Chapter 10. Installing with RHEL KVM on IBM Z and LinuxONE

10.1. Installing a cluster with RHEL KVM on IBM Z and LinuxONE

In OpenShift Container Platform version 4.7, you can install a cluster on IBM Z or LinuxONE infrastructure that you provision.

Note

While this document refers only to IBM Z, all information in it also applies to LinuxONE.

Important

Additional considerations exist for non-bare metal platforms. Review the information in the guidelines for deploying OpenShift Container Platform on non-tested platforms before you install an OpenShift Container Platform cluster.

10.1.1. Prerequisites

Before you begin the installation process, you must clean the installation directory. This ensures that the required installation files are created and updated during the installation process.
Provision persistent storage using NFS for your cluster. To deploy a private image registry, your storage must provide ReadWriteMany access modes.
Review details about the OpenShift Container Platform installation and update processes.
If you use a firewall, you must configure it to allow the sites that your cluster requires access to.
RHEL Kernel Virtual Machine (KVM) system that is hosted on the logical partition (LPAR) and based on RHEL 8.4 or later
Note
Be sure to also review this site list if you are configuring a proxy.

10.1.2. Internet access for OpenShift Container Platform

In OpenShift Container Platform 4.7, you require access to the Internet to install your cluster.

You must have Internet access to:

Access OpenShift Cluster Manager to download the installation program and perform subscription management. If the cluster has internet access and you do not disable Telemetry, that service automatically entitles your cluster.
Access Quay.io to obtain the packages that are required to install your cluster.
Obtain the packages that are required to perform cluster updates.

Important

If your cluster cannot have direct Internet access, you can perform a restricted network installation on some types of infrastructure that you provision. During that process, you download the content that is required and use it to populate a mirror registry with the packages that you need to install a cluster and generate the installation program. With some installation types, the environment that you install your cluster in will not require Internet access. Before you update the cluster, you update the content of the mirror registry.

10.1.3. Machine requirements for a cluster with user-provisioned infrastructure

For a cluster that contains user-provisioned infrastructure, you must deploy all of the required machines.

One or more KVM host machines based on RHEL 8.4 or later. Each RHEL KVM host machine must have libvirt installed and running. The virtual machines are provisioned under each RHEL KVM host machine.

10.1.3.1. Required machines

The smallest OpenShift Container Platform clusters require the following nodes:

One temporary bootstrap machine
Three control plane, or master, machines
At least two compute machines, which are also known as worker machines

Note

The cluster requires the bootstrap machine to deploy the OpenShift Container Platform cluster on the three control plane machines. You can remove the bootstrap machine after you install the cluster.

Important

To improve high availability of your cluster, distribute the control plane machines over different RHEL instances on at least two physical machines.

The bootstrap, control plane, and compute machines must use Red Hat Enterprise Linux CoreOS (RHCOS) as the operating system.

See Red Hat Enterprise Linux technology capabilities and limits.

10.1.3.2. Network connectivity requirements

The OpenShift Container Platform installer creates the Ignition files, which are necessary for all the Red Hat Enterprise Linux CoreOS (RHCOS) virtual machines. The automated installation of OpenShift Container Platform is performed by the bootstrap machine. It starts the installation of OpenShift Container Platform on each node, starts the Kubernetes cluster, and then finishes. During this bootstrap, the virtual machine must have an established network connection either through a Dynamic Host Configuration Protocol (DHCP) server or static IP address.

10.1.3.3. IBM Z network connectivity requirements

To install on IBM Z under RHEL KVM, you need:

A RHEL KVM host configured with an OSA or RoCE network adapter.
Either a RHEL KVM host that is configured to use bridged networking in libvirt or MacVTap to connect the network to the guests.
See Types of virtual network connections.

10.1.3.4. Host machine resource requirements

The RHEL KVM host in your environment must meet the following requirements to host the virtual machines that you plan for the OpenShift Container Platform environment. See Getting started with virtualization.

You can install OpenShift Container Platform version 4.7 on the following IBM hardware:

IBM z15 (all models), IBM z14 (all models), IBM z13, and IBM z13s
LinuxONE, any version

10.1.3.5. Minimum IBM Z system environment

Hardware requirements

The equivalent of six IFLs, which are SMT2 enabled, for each cluster.
At least one network connection to both connect to the LoadBalancer service and to serve data for traffic outside the cluster.

Note

You can use dedicated or shared IFLs to assign sufficient compute resources. Resource sharing is one of the key strengths of IBM Z. However, you must adjust capacity correctly on each hypervisor layer and ensure sufficient resources for every OpenShift Container Platform cluster.

Important

Since the overall performance of the cluster can be impacted, the LPARs that are used to setup the OpenShift Container Platform clusters must provide sufficient compute capacity. In this context, LPAR weight management, entitlements, and CPU shares on the hypervisor level play an important role.

Operating system requirements

One LPAR running RHEL 8.4 or later with KVM, which is managed by libvirt

On your RHEL KVM host, set up:

Three guest virtual machines for OpenShift Container Platform control plane machines
Two guest virtual machines for OpenShift Container Platform compute machines
One guest virtual machine for the temporary OpenShift Container Platform bootstrap machine

10.1.3.6. Minimum resource requirements

Each cluster virtual machine must meet the following minimum requirements:

Virtual Machine	Operating System	vCPU ^[1]	Virtual RAM	Storage	IOPS
Bootstrap	RHCOS	4	16 GB	100 GB	N/A
Control plane	RHCOS	4	16 GB	100 GB	N/A
Compute	RHCOS	2	8 GB	100 GB	N/A

One physical core (IFL) provides two logical cores (threads) when SMT-2 is enabled. The hypervisor can provide two or more vCPUs.

10.1.3.7. Preferred IBM Z system environment

Hardware requirements

Three LPARS that each have the equivalent of six IFLs, which are SMT2 enabled, for each cluster.
Two network connections to connect to both connect to the LoadBalancer service and to serve data for traffic outside the cluster.

Operating system requirements

For high availability, two or three LPARs running RHEL 8.4 or later with KVM, which are managed by libvirt.

On your RHEL KVM host, set up:

Three guest virtual machines for OpenShift Container Platform control plane machines, distributed across the RHEL KVM host machines.
At least six guest virtual machines for OpenShift Container Platform compute machines, distributed across the RHEL KVM host machines.
One guest virtual machine for the temporary OpenShift Container Platform bootstrap machine.
To ensure the availability of integral components in an overcommitted environment, increase the priority of the control plane by using cpu_shares. Do the same for infrastructure nodes, if they exist. See schedinfo in IBM Documentation.

10.1.3.8. Preferred resource requirements

The preferred requirements for each cluster virtual machine are:

Virtual Machine	Operating System	vCPU	Virtual RAM	Storage
Bootstrap	RHCOS	4	16 GB	120 GB
Control plane	RHCOS	8	16 GB	120 GB
Compute	RHCOS	6	8 GB	120 GB

10.1.3.9. Certificate signing requests management

Because your cluster has limited access to automatic machine management when you use infrastructure that you provision, you must provide a mechanism for approving cluster certificate signing requests (CSRs) after installation. The kube-controller-manager only approves the kubelet client CSRs. The machine-approver cannot guarantee the validity of a serving certificate that is requested by using kubelet credentials because it cannot confirm that the correct machine issued the request. You must determine and implement a method of verifying the validity of the kubelet serving certificate requests and approving them.

Additional resources

Recommended host practices for IBM Z & LinuxONE environments

10.1.4. Creating the user-provisioned infrastructure

Before you deploy an OpenShift Container Platform cluster that uses user-provisioned infrastructure, you must create the underlying infrastructure.

Prerequisites

Review the OpenShift Container Platform 4.x Tested Integrations page before you create the supporting infrastructure for your cluster.

Procedure

Configure DHCP or set static IP addresses on each node.
Choose to perform either a fast track installation of Red Hat Enterprise Linux CoreOS (RHCOS) or a full installation of Red Hat Enterprise Linux CoreOS (RHCOS). For the full installation you must set up an HTTP or HTTPS server to provide Ignition files and install images to the cluster nodes. For the fast track installation an HTTP or HTTPS server is not required, however, a DHCP server is required. See sections “Fast-track installation: Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines" and “Full installation: Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines".
Provision the required load balancers.
Configure the ports for your machines.
Configure DNS.
Ensure network connectivity.

10.1.4.1. Networking requirements for user-provisioned infrastructure

All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require network in initramfs during boot to fetch Ignition config from the machine config server.

During the initial boot, the machines require either a DHCP server or that static IP addresses be set on each host in the cluster to establish a network connection, which allows them to download their Ignition config files.

It is recommended to use the DHCP server to manage the machines for the cluster long-term. Ensure that the DHCP server is configured to provide persistent IP addresses and host names to the cluster machines.

The Kubernetes API server must be able to resolve the node names of the cluster machines. If the API servers and worker nodes are in different zones, you can configure a default DNS search zone to allow the API server to resolve the node names. Another supported approach is to always refer to hosts by their fully-qualified domain names in both the node objects and all DNS requests.

You must configure the network connectivity between machines to allow cluster components to communicate. Each machine must be able to resolve the host names of all other machines in the cluster.

Note

The RHEL KVM host must be configured to use bridged networking in libvirt or MacVTap to connect the network to the virtual machines. The virtual machines must have access to the network, which is attached to the RHEL KVM host. Virtual Networks, for example network address translation (NAT), within KVM are not a supported configuration.

Table 10.1. All machines to all machines
Protocol	Port	Description
ICMP	N/A	Network reachability tests
TCP	`1936`	Metrics
	`9000`-`9999`	Host level services, including the node exporter on ports `9100`-`9101` and the Cluster Version Operator on port `9099`.
	`10250`-`10259`	The default ports that Kubernetes reserves
	`10256`	openshift-sdn
UDP	`4789`	VXLAN and Geneve
	`6081`	VXLAN and Geneve
	`9000`-`9999`	Host level services, including the node exporter on ports `9100`-`9101`.
TCP/UDP	`30000`-`32767`	Kubernetes node port

Table 10.2. All machines to control plane
Protocol	Port	Description
TCP	`6443`	Kubernetes API

Table 10.3. Control plane machines to control plane machines
Protocol	Port	Description
TCP	`2379`-`2380`	etcd server and peer ports

Network topology requirements

The infrastructure that you provision for your cluster must meet the following network topology requirements.

Important

OpenShift Container Platform requires all nodes to have internet access to pull images for platform containers and provide telemetry data to Red Hat.

Load balancers

Before you install OpenShift Container Platform, you must provision two load balancers that meet the following requirements:

API load balancer: Provides a common endpoint for users, both human and machine, to interact with and configure the platform. Configure the following conditions:

Layer 4 load balancing only. This can be referred to as Raw TCP, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the API routes.
A stateless load balancing algorithm. The options vary based on the load balancer implementation.

Important

Do not configure session persistence for an API load balancer.

Configure the following ports on both the front and back of the load balancers:

Table 10.4. API load balancer
Port	Back-end machines (pool members)	Internal	External	Description
`6443`	Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane. You must configure the `/readyz` endpoint for the API server health check probe.	X	X	Kubernetes API server
`22623`	Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane.	X		Machine config server

Note

The load balancer must be configured to take a maximum of 30 seconds from the time the API server turns off the /readyz endpoint to the removal of the API server instance from the pool. Within the time frame after /readyz returns an error or becomes healthy, the endpoint must have been removed or added. Probing every 5 or 10 seconds, with two successful requests to become healthy and three to become unhealthy, are well-tested values.

Application Ingress load balancer: Provides an Ingress point for application traffic flowing in from outside the cluster. Configure the following conditions:

Layer 4 load balancing only. This can be referred to as Raw TCP, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the Ingress routes.
A connection-based or session-based persistence is recommended, based on the options available and types of applications that will be hosted on the platform.

Configure the following ports on both the front and back of the load balancers:

Table 10.5. Application Ingress load balancer
Port	Back-end machines (pool members)	Internal	External	Description
`443`	The machines that run the Ingress router pods, compute, or worker, by default.	X	X	HTTPS traffic
`80`	The machines that run the Ingress router pods, compute, or worker, by default.	X	X	HTTP traffic

Tip

If the true IP address of the client can be seen by the load balancer, enabling source IP-based session persistence can improve performance for applications that use end-to-end TLS encryption.

Note

A working configuration for the Ingress router is required for an OpenShift Container Platform cluster. You must configure the Ingress router after the control plane initializes.

NTP configuration

OpenShift Container Platform clusters are configured to use a public Network Time Protocol (NTP) server by default. If you want to use a local enterprise NTP server, or if your cluster is being deployed in a disconnected network, you can configure the cluster to use a specific time server. For more information, see the documentation for Configuring chrony time service.

If a DHCP server provides NTP server information, the chrony time service on the Red Hat Enterprise Linux CoreOS (RHCOS) machines read the information and can sync the clock with the NTP servers.

Additional resources

Configuring chrony time service

10.1.4.2. User-provisioned DNS requirements

DNS is used for name resolution and reverse name resolution. DNS A/AAAA or CNAME records are used for name resolution and PTR records are used for reverse name resolution. The reverse records are important because Red Hat Enterprise Linux CoreOS (RHCOS) uses the reverse records to set the host name for all the nodes. Additionally, the reverse records are used to generate the certificate signing requests (CSR) that OpenShift Container Platform needs to operate.

The following DNS records are required for an OpenShift Container Platform cluster that uses user-provisioned infrastructure. In each record, <cluster_name> is the cluster name and <base_domain> is the cluster base domain that you specify in the install-config.yaml file. A complete DNS record takes the form: <component>.<cluster_name>.<base_domain>..

Table 10.6. Required DNS records
Component	Record	Description
Kubernetes API	`api.<cluster_name>.<base_domain>.`	Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.
Kubernetes API	`api-int.<cluster_name>.<base_domain>.`	Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. These records must be resolvable from all the nodes within the cluster. Important The API server must be able to resolve the worker nodes by the host names that are recorded in Kubernetes. If the API server cannot resolve the node names, then proxied API calls can fail, and you cannot retrieve logs from pods.
Routes	`*.apps.<cluster_name>.<base_domain>.`	Add a wildcard DNS A/AAAA or CNAME record that refers to the load balancer that targets the machines that run the Ingress router pods, which are the worker nodes by default. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.
Bootstrap	`bootstrap.<cluster_name>.<base_domain>.`	Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the bootstrap machine. These records must be resolvable by the nodes within the cluster.
Master hosts	`<master><n>.<cluster_name>.<base_domain>.`	DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the control plane nodes (also known as the master nodes). These records must be resolvable by the nodes within the cluster.
Worker hosts	`<worker><n>.<cluster_name>.<base_domain>.`	Add DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the worker nodes. These records must be resolvable by the nodes within the cluster.

Tip

You can use the nslookup <hostname> command to verify name resolution. You can use the dig -x <ip_address> command to verify reverse name resolution for the PTR records.

The following example of a BIND zone file shows sample A records for name resolution. The purpose of the example is to show the records that are needed. The example is not meant to provide advice for choosing one name resolution service over another.

Example 10.1. Sample DNS zone database

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
	IN	MX 10	smtp.example.com.
;
;
ns1	IN	A	192.168.1.5
smtp	IN	A	192.168.1.5
;
helper	IN	A	192.168.1.5
helper.ocp4	IN	A	192.168.1.5
;
; The api identifies the IP of your load balancer.
api.ocp4		IN	A	192.168.1.5
api-int.ocp4		IN	A	192.168.1.5
;
; The wildcard also identifies the load balancer.
*.apps.ocp4		IN	A	192.168.1.5
;
; Create an entry for the bootstrap host.
bootstrap.ocp4	IN	A	192.168.1.96
;
; Create entries for the master hosts.
master0.ocp4		IN	A	192.168.1.97
master1.ocp4		IN	A	192.168.1.98
master2.ocp4		IN	A	192.168.1.99
;
; Create entries for the worker hosts.
worker0.ocp4		IN	A	192.168.1.11
worker1.ocp4		IN	A	192.168.1.7
;
;EOF

The following example BIND zone file shows sample PTR records for reverse name resolution.

Example 10.2. Sample DNS zone database for reverse records

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
;
; The syntax is "last octet" and the host must have an FQDN
; with a trailing dot.
97	IN	PTR	master0.ocp4.example.com.
98	IN	PTR	master1.ocp4.example.com.
99	IN	PTR	master2.ocp4.example.com.
;
96	IN	PTR	bootstrap.ocp4.example.com.
;
5	IN	PTR	api.ocp4.example.com.
5	IN	PTR	api-int.ocp4.example.com.
;
11	IN	PTR	worker0.ocp4.example.com.
7	IN	PTR	worker1.ocp4.example.com.
;
;EOF

10.1.5. Generating an SSH private key and adding it to the agent

If you want to perform installation debugging or disaster recovery on your cluster, you must provide an SSH key to both your ssh-agent and the installation program. You can use this key to access the bootstrap machine in a public cluster to troubleshoot installation issues.

Note

In a production environment, you require disaster recovery and debugging.

Important

Do not skip this procedure in production environments where disaster recovery and debugging is required.

You can use this key to SSH into the master nodes as the user core. When you deploy the cluster, the key is added to the core user’s ~/.ssh/authorized_keys list.

Procedure

If you do not have an SSH key that is configured for password-less authentication on your computer, create one. For example, on a computer that uses a Linux operating system, run the following command:
```
$ ssh-keygen -t ed25519 -N '' \
    -f <path>/<file_name> 1
```
1
Specify the path and file name, such as ~/.ssh/id_rsa, of the new SSH key. If you have an existing key pair, ensure your public key is in the your ~/.ssh directory.
Running this command generates an SSH key that does not require a password in the location that you specified.
Note
If you plan to install an OpenShift Container Platform cluster that uses FIPS Validated / Modules in Process cryptographic libraries on the x86_64 architecture, do not create a key that uses the ed25519 algorithm. Instead, create a key that uses the rsa or ecdsa algorithm.
Start the ssh-agent process as a background task:
```
$ eval "$(ssh-agent -s)"
```
Example output
```
Agent pid 31874
```
Note
If your cluster is in FIPS mode, only use FIPS-compliant algorithms to generate the SSH key. The key must be either RSA or ECDSA.
Add your SSH private key to the ssh-agent:
```
$ ssh-add <path>/<file_name> 1
```
Example output
```
Identity added: /home/<you>/<path>/<file_name> (<computer_name>)
```
1
Specify the path and file name for your SSH private key, such as ~/.ssh/id_rsa

Next steps

When you install OpenShift Container Platform, provide the SSH public key to the installation program.

10.1.6. Obtaining the installation program

Before you install OpenShift Container Platform, download the installation file on your provisioning machine.

Prerequisites

You have a machine that runs Linux, for example Red Hat Enterprise Linux 8, with 500 MB of local disk space

Procedure

Access the Infrastructure Provider page on the OpenShift Cluster Manager site. If you have a Red Hat account, log in with your credentials. If you do not, create an account.
Select your infrastructure provider.
Navigate to the page for your installation type, download the installation program for your operating system, and place the file in the directory where you will store the installation configuration files.
Important
The installation program creates several files on the computer that you use to install your cluster. You must keep the installation program and the files that the installation program creates after you finish installing the cluster. Both files are required to delete the cluster.
Important
Deleting the files created by the installation program does not remove your cluster, even if the cluster failed during installation. To remove your cluster, complete the OpenShift Container Platform uninstallation procedures for your specific cloud provider.
Extract the installation program. For example, on a computer that uses a Linux operating system, run the following command:
```
$ tar xvf openshift-install-linux.tar.gz
```
Download your installation pull secret from the Red Hat OpenShift Cluster Manager. This pull secret allows you to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OpenShift Container Platform components.

10.1.7. Installing the OpenShift CLI by downloading the binary

You can install the OpenShift CLI (oc) to interact with OpenShift Container Platform from a command-line interface. You can install oc on Linux, Windows, or macOS.

Important

If you installed an earlier version of oc, you cannot use it to complete all of the commands in OpenShift Container Platform 4.7. Download and install the new version of oc.

10.1.7.1. Installing the OpenShift CLI on Linux

You can install the OpenShift CLI (oc) binary on Linux by using the following procedure.

Procedure

Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
Select the appropriate version in the Version drop-down menu.
Click Download Now next to the OpenShift v4.7 Linux Client entry and save the file.
Unpack the archive:
```
$ tar xvzf <file>
```
Place the oc binary in a directory that is on your PATH.
To check your PATH, execute the following command:
```
$ echo $PATH
```

After you install the OpenShift CLI, it is available using the oc command:

$ oc <command>

10.1.7.2. Installing the OpenShift CLI on Windows

You can install the OpenShift CLI (oc) binary on Windows by using the following procedure.

Procedure

Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
Select the appropriate version in the Version drop-down menu.
Click Download Now next to the OpenShift v4.7 Windows Client entry and save the file.
Unzip the archive with a ZIP program.
Move the oc binary to a directory that is on your PATH.
To check your PATH, open the command prompt and execute the following command:
```
C:\> path
```

After you install the OpenShift CLI, it is available using the oc command:

C:\> oc <command>

10.1.7.3. Installing the OpenShift CLI on macOS

You can install the OpenShift CLI (oc) binary on macOS by using the following procedure.

Procedure

Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
Select the appropriate version in the Version drop-down menu.
Click Download Now next to the OpenShift v4.7 MacOSX Client entry and save the file.
Unpack and unzip the archive.
Move the oc binary to a directory on your PATH.
To check your PATH, open a terminal and execute the following command:
```
$ echo $PATH
```

After you install the OpenShift CLI, it is available using the oc command:

$ oc <command>

10.1.8. Manually creating the installation configuration file

For installations of OpenShift Container Platform that use user-provisioned infrastructure, you manually generate your installation configuration file.

Prerequisites

Obtain the OpenShift Container Platform installation program and the access token for your cluster.

Procedure

Create an installation directory to store your required installation assets in:
```
$ mkdir <installation_directory>
```
Important
You must create a directory. Some installation assets, like bootstrap X.509 certificates have short expiration intervals, so you must not reuse an installation directory. If you want to reuse individual files from another cluster installation, you can copy them into your directory. However, the file names for the installation assets might change between releases. Use caution when copying installation files from an earlier OpenShift Container Platform version.
Customize the following install-config.yaml file template and save it in the <installation_directory>.
Note
You must name this configuration file install-config.yaml.
Back up the install-config.yaml file so that you can use it to install multiple clusters.
Important
The install-config.yaml file is consumed during the next step of the installation process. You must back it up now.

10.1.8.1. Sample install-config.yaml file for IBM Z

You can customize the install-config.yaml file to specify more details about your OpenShift Container Platform cluster’s platform or modify the values of the required parameters.

apiVersion: v1
baseDomain: example.com 1
compute: 2
- hyperthreading: Enabled 3
  name: worker
  replicas: 0 4
  architecture : s390x
controlPlane: 5
  hyperthreading: Enabled 6
  name: master
  replicas: 3 7
  architecture : s390x
metadata:
  name: test 8
networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14 9
    hostPrefix: 23 10
  networkType: OpenShiftSDN
  serviceNetwork: 11
  - 172.30.0.0/16
platform:
  none: {} 12
fips: false 13
pullSecret: '{"auths": ...}' 14
sshKey: 'ssh-ed25519 AAAA...' 15

1

The base domain of the cluster. All DNS records must be sub-domains of this base and include the cluster name.

2 5

The controlPlane section is a single mapping, but the compute section is a sequence of mappings. To meet the requirements of the different data structures, the first line of the compute section must begin with a hyphen, -, and the first line of the controlPlane section must not. Only one control plane pool is used.

3 6

Whether to enable or disable simultaneous multithreading (SMT), or hyperthreading. By default, SMT is enabled to increase the performance of your machines' cores. You can disable it by setting the parameter value to Disabled. If you disable SMT, you must disable it in all cluster machines; this includes both control plane and compute machines.

Note

Simultaneous multithreading (SMT) is enabled by default. If SMT is not enabled in your BIOS settings, the hyperthreading parameter has no effect.

Important

If you disable hyperthreading, whether in the BIOS or in the install-config.yaml, ensure that your capacity planning accounts for the dramatically decreased machine performance.

4

You must set the value of the replicas parameter to 0. This parameter controls the number of workers that the cluster creates and manages for you, which are functions that the cluster does not perform when you use user-provisioned infrastructure. You must manually deploy worker machines for the cluster to use before you finish installing OpenShift Container Platform.

7

The number of control plane machines that you add to the cluster. Because the cluster uses these values as the number of etcd endpoints in the cluster, the value must match the number of control plane machines that you deploy.

8

The cluster name that you specified in your DNS records.

9

A block of IP addresses from which pod IP addresses are allocated. This block must not overlap with existing physical networks. These IP addresses are used for the pod network. If you need to access the pods from an external network, you must configure load balancers and routers to manage the traffic.

Note

Class E CIDR range is reserved for a future use. To use the Class E CIDR range, you must ensure your networking environment accepts the IP addresses within the Class E CIDR range.

10

The subnet prefix length to assign to each individual node. For example, if hostPrefix is set to 23, then each node is assigned a /23 subnet out of the given cidr, which allows for 510 (2^(32 - 23) - 2) pod IPs addresses. If you are required to provide access to nodes from an external network, configure load balancers and routers to manage the traffic.

11

The IP address pool to use for service IP addresses. You can enter only one IP address pool. This block must not overlap with existing physical networks. If you need to access the services from an external network, configure load balancers and routers to manage the traffic.

12

You must set the platform to none. You cannot provide additional platform configuration variables for IBM Z infrastructure.

Warning

Red Hat Virtualization does not currently support installation with user-provisioned infrastructure on the oVirt platform. Therefore, you must set the platform to none, allowing OpenShift Container Platform to identify each node as a bare-metal node and the cluster as a bare-metal cluster. This is the same as installing a cluster on any platform, and has the following limitations:

There will be no cluster provider so you must manually add each machine and there will be no node scaling capabilities.
The oVirt CSI driver will not be installed and there will be no CSI capabilities.

13

Whether to enable or disable FIPS mode. By default, FIPS mode is not enabled. If FIPS mode is enabled, the Red Hat Enterprise Linux CoreOS (RHCOS) machines that OpenShift Container Platform runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with RHCOS instead.

Important

The use of FIPS Validated / Modules in Process cryptographic libraries is only supported on OpenShift Container Platform deployments on the x86_64 architecture.

14

The pull secret from the Red Hat OpenShift Cluster Manager. This pull secret allows you to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OpenShift Container Platform components.

15

The public portion of the default SSH key for the core user in Red Hat Enterprise Linux CoreOS (RHCOS).

Note

For production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your ssh-agent process uses.

10.1.9. Configuring the cluster-wide proxy during installation

Production environments can deny direct access to the Internet and instead have an HTTP or HTTPS proxy available. You can configure a new OpenShift Container Platform cluster to use a proxy by configuring the proxy settings in the install-config.yaml file.

Prerequisites

You have an existing install-config.yaml file.
You reviewed the sites that your cluster requires access to and determined whether any of them need to bypass the proxy. By default, all cluster egress traffic is proxied, including calls to hosting cloud provider APIs. You added sites to the Proxy object’s spec.noProxy field to bypass the proxy if necessary.
Note
The Proxy object status.noProxy field is populated with the values of the networking.machineNetwork[].cidr, networking.clusterNetwork[].cidr, and networking.serviceNetwork[] fields from your installation configuration.
For installations on Amazon Web Services (AWS), Google Cloud Platform (GCP), Microsoft Azure, and Red Hat OpenStack Platform (RHOSP), the Proxy object status.noProxy field is also populated with the instance metadata endpoint (169.254.169.254).

Procedure

Edit your install-config.yaml file and add the proxy settings. For example:
```
apiVersion: v1
baseDomain: my.domain.com
proxy:
  httpProxy: http://<username>:<pswd>@<ip>:<port> 1
  httpsProxy: https://<username>:<pswd>@<ip>:<port> 2
  noProxy: example.com 3
additionalTrustBundle: | 4
    -----BEGIN CERTIFICATE-----
    <MY_TRUSTED_CA_CERT>
    -----END CERTIFICATE-----
...
```
1
A proxy URL to use for creating HTTP connections outside the cluster. The URL scheme must be http.
2
A proxy URL to use for creating HTTPS connections outside the cluster.
3
A comma-separated list of destination domain names, IP addresses, or other network CIDRs to exclude from proxying. Preface a domain with . to match subdomains only. For example, .y.com matches x.y.com, but not y.com. Use * to bypass the proxy for all destinations.
4
If provided, the installation program generates a config map that is named user-ca-bundle in the openshift-config namespace to hold the additional CA certificates. If you provide additionalTrustBundle and at least one proxy setting, the Proxy object is configured to reference the user-ca-bundle config map in the trustedCA field. The Cluster Network Operator then creates a trusted-ca-bundle config map that merges the contents specified for the trustedCA parameter with the RHCOS trust bundle. The additionalTrustBundle field is required unless the proxy’s identity certificate is signed by an authority from the RHCOS trust bundle.
Note
The installation program does not support the proxy readinessEndpoints field.
Save the file and reference it when installing OpenShift Container Platform.

The installation program creates a cluster-wide proxy that is named cluster that uses the proxy settings in the provided install-config.yaml file. If no proxy settings are provided, a cluster Proxy object is still created, but it will have a nil spec.

Note

Only the Proxy object named cluster is supported, and no additional proxies can be created.

10.1.10. Creating the Kubernetes manifest and Ignition config files

Because you must modify some cluster definition files and manually start the cluster machines, you must generate the Kubernetes manifest and Ignition config files that the cluster needs to make its machines.

The installation configuration file transforms into the Kubernetes manifests. The manifests wrap into the Ignition configuration files, which are later used to create the cluster.

Important

The Ignition config files that the installation program generates contain certificates that expire after 24 hours, which are then renewed at that time. If the cluster is shut down before renewing the certificates and the cluster is later restarted after the 24 hours have elapsed, the cluster automatically recovers the expired certificates. The exception is that you must manually approve the pending node-bootstrapper certificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information.

Note

The installation program that generates the manifest and Ignition files is architecture specific and can be obtained from the client image mirror. The Linux version of the installation program runs on s390x only. This installer program is also available as a Mac OS version.

Prerequisites

You obtained the OpenShift Container Platform installation program.
You created the install-config.yaml installation configuration file.

Procedure

Change to the directory that contains the installation program and generate the Kubernetes manifests for the cluster:
```
$ ./openshift-install create manifests --dir <installation_directory> 1
```
1
For <installation_directory>, specify the installation directory that contains the install-config.yaml file you created.
Warning
If you are installing a three-node cluster, skip the following step to allow the control plane nodes to be schedulable.
Important
When you configure control plane nodes from the default unschedulable to schedulable, additional subscriptions are required. This is because control plane nodes then become worker nodes.
Check that the mastersSchedulable parameter in the <installation_directory>/manifests/cluster-scheduler-02-config.yml Kubernetes manifest file is set to false. This setting prevents pods from being scheduled on the control plane machines:
1. Open the <installation_directory>/manifests/cluster-scheduler-02-config.yml file.
2. Locate the mastersSchedulable parameter and ensure that it is set to false.
3. Save and exit the file.
To create the Ignition configuration files, run the following command from the directory that contains the installation program:
```
$ ./openshift-install create ignition-configs --dir <installation_directory> 1
```
1
For <installation_directory>, specify the same installation directory.
The following files are generated in the directory:
```
.
├── auth
│   ├── kubeadmin-password
│   └── kubeconfig
├── bootstrap.ign
├── master.ign
├── metadata.json
└── worker.ign
```

10.1.11. Fast-track installation: Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines

Before you install a cluster on IBM Z infrastructure that you provision, you must install RHCOS as Red Hat Enterprise Linux (RHEL) guest virtual machines for the cluster to use. Complete the following steps to create the machines in a fast-track installation of Red Hat Enterprise Linux CoreOS (RHCOS), importing a prepackaged Red Hat Enterprise Linux CoreOS (RHCOS) QEMU copy-on-write (QCOW2) disk image.

Prerequisites

At least one LPAR running RHEL 8.4 with KVM, referred to as RHEL KVM host in this procedure.
The KVM/QEMU hypervisor is installed on the RHEL KVM host.
A domain name server (DNS) that can perform hostname and reverse lookup for the nodes.
A DHCP server that provides IP addresses.

Procedure

Obtain the RHEL QEMU copy-on-write (QCOW2) disk image file from the Product Downloads page on the Red Hat Customer Portal or from the RHCOS image mirror page.
Important
The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Only use the appropriate RHCOS QCOW2 image described in the following procedure.
Download the QCOW2 disk image and Ignition files to a common directory on the RHEL KVM host.
For example: /var/lib/libvirt/images
Note
The Ignition files are generated by the OpenShift Container Platform installer.

Create a new disk image with the QCOW2 disk image backing file for each KVM guest node.

$ qemu-img create -f qcow2 -F qcow2 -b /var/lib/libvirt/images/{source_rhcos_qemu} /var/lib/libvirt/images/{vmname}.qcow2 {size}

Create the new KVM guest nodes using the Ignition file and the new disk image.

$ virt-install --noautoconsole \
   --connect qemu:///system \
   --name {vn_name} \
   --memory {memory} \
   --vcpus {vcpus} \
   --disk {disk} \
   --import \
   --network network={network},mac={mac} \
   --qemu-commandline="-drive \
if=none,id=ignition,format=raw,file={ign_file},readonly=on -device virtio-blk,serial=ignition,drive=ignition"

10.1.12. Full installation: Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines

Before you install a cluster on IBM Z infrastructure that you provision, you must install RHCOS as Red Hat Enterprise Linux (RHEL) guest virtual machines for the cluster to use. Complete the following steps to create the machines in a full installation on a new QEMU copy-on-write (QCOW2) disk image.

Prerequisites

At least 1 LPAR running RHEL 8.3 with KVM, referred to as RHEL KVM host in this procedure.
The KVM/QEMU hypervisor is installed on the RHEL KVM host.
A domain name server (DNS) that can perform hostname and reverse lookup for the nodes.
An HTTP or HTTPS server is set up.

Procedure

Obtain the RHEL kernel, initramfs, and rootfs files from the Product Downloads page on the Red Hat Customer Portal or from the RHCOS image mirror page.
Important
The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Only use the appropriate RHCOS QCOW2 image described in the following procedure.
The file names contain the OpenShift Container Platform version number. They resemble the following examples:
- kernel: rhcos-<version>-live-kernel-<architecture>
- initramfs: rhcos-<version>-live-initramfs.<architecture>.img
- rootfs: rhcos-<version>-live-rootfs.<architecture>.img
Move the downloaded RHEL live kernel, initramfs, and rootfs as well as the Ignition files to an HTTP or HTTPS server before you launch virt-install.
Note
The Ignition files are generated by the OpenShift Container Platform installer.

Create the new KVM guest nodes using the RHEL kernel, initramfs, and Ignition files, the new disk image, and adjusted parm line arguments.

For --location, specify the location of the kernel/initrd on the HTTP or HTTPS server.
For coreos.inst.ignition_url=, specify the Ignition file for the machine role. Use bootstrap.ign, master.ign, or worker.ign. Only HTTP and HTTPS protocols are supported.

For coreos.live.rootfs_url=, specify the matching rootfs artifact for the kernel and initramfs you are booting. Only HTTP and HTTPS protocols are supported.

$ virt-install \
   --connect qemu:///system \
   --name {vn_name} \
   --vcpus {vcpus} \
   --memory {memory_mb} \
   --disk {vn_name}.qcow2,size={image_size| default(10,true)} \
   --network network={virt_network_parm} \
   --boot hd \
   --location {media_location},kernel={rhcos_kernel},initrd={rhcos_initrd} \
   --extra-args "rd.neednet=1 dfltcc=off coreos.inst=yes coreos.inst.install_dev=vda coreos.live.rootfs_url={rhcos_liveos} ip={ip}::{default_gateway}:{subnet_mask_length}:{vn_name}:enc1:none:{MTU} nameserver={dns} coreos.inst.ignition_url={rhcos_ign}" \
   --noautoconsole \
   --wait

Note

dfltcc=off is required for IBM z15 and LinuxONE III.

10.1.13. Creating the cluster

To create the OpenShift Container Platform cluster, you wait for the bootstrap process to complete on the machines that you provisioned by using the Ignition config files that you generated with the installation program.

Prerequisites

Create the required infrastructure for the cluster.
You obtained the installation program and generated the Ignition config files for your cluster.
You used the Ignition config files to create RHCOS machines for your cluster.
Your machines have direct Internet access or have an HTTP or HTTPS proxy available.

Procedure

Monitor the bootstrap process:
```
$ ./openshift-install --dir <installation_directory> wait-for bootstrap-complete \ 1
    --log-level=info 2
```
1
For <installation_directory>, specify the path to the directory that you stored the installation files in.
2
To view different installation details, specify warn, debug, or error instead of info.
Example output
```
INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443...
INFO API v1.20.0 up
INFO Waiting up to 30m0s for bootstrapping to complete...
INFO It is now safe to remove the bootstrap resources
```
The command succeeds when the Kubernetes API server signals that it has been bootstrapped on the control plane machines.
After bootstrap process is complete, remove the bootstrap machine from the load balancer.
Important
You must remove the bootstrap machine from the load balancer at this point. You can also remove or reformat the machine itself.

10.1.14. Logging in to the cluster by using the CLI

You can log in to your cluster as a default system user by exporting the cluster kubeconfig file. The kubeconfig file contains information about the cluster that is used by the CLI to connect a client to the correct cluster and API server. The file is specific to a cluster and is created during OpenShift Container Platform installation.

Prerequisites

You deployed an OpenShift Container Platform cluster.
You installed the oc CLI.

Procedure

Export the kubeadmin credentials:
```
$ export KUBECONFIG=<installation_directory>/auth/kubeconfig 1
```
1
For <installation_directory>, specify the path to the directory that you stored the installation files in.
Verify you can run oc commands successfully using the exported configuration:
```
$ oc whoami
```
Example output
```
system:admin
```

10.1.15. Approving the certificate signing requests for your machines

When you add machines to a cluster, two pending certificate signing requests (CSRs) are generated for each machine that you added. You must confirm that these CSRs are approved or, if necessary, approve them yourself. The client requests must be approved first, followed by the server requests.

Prerequisites

You added machines to your cluster.

Procedure

Confirm that the cluster recognizes the machines:
```
$ oc get nodes
```
Example output
```
NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  63m  v1.20.0
master-1  Ready     master  63m  v1.20.0
master-2  Ready     master  64m  v1.20.0
```
The output lists all of the machines that you created.
Note
The preceding output might not include the compute nodes, also known as worker nodes, until some CSRs are approved.

Review the pending CSRs and ensure that you see the client requests with the Pending or Approved status for each machine that you added to the cluster:

$ oc get csr

Example output

NAME        AGE   REQUESTOR                                   CONDITION
csr-mddf5   20m   system:node:master-01.example.com   Approved,Issued
csr-z5rln   16m   system:node:worker-21.example.com   Approved,Issued

If the CSRs were not approved, after all of the pending CSRs for the machines you added are in Pending status, approve the CSRs for your cluster machines:
Note
Because the CSRs rotate automatically, approve your CSRs within an hour of adding the machines to the cluster. If you do not approve them within an hour, the certificates will rotate, and more than two certificates will be present for each node. You must approve all of these certificates. Once the client CSR is approved, the Kubelet creates a secondary CSR for the serving certificate, which requires manual approval. Then, subsequent serving certificate renewal requests are automatically approved by the machine-approver if the Kubelet requests a new certificate with identical parameters.
Note
For clusters running on platforms that are not machine API enabled, such as bare metal and other user-provisioned infrastructure, you must implement a method of automatically approving the kubelet serving certificate requests (CSRs). If a request is not approved, then the oc exec, oc rsh, and oc logs commands cannot succeed, because a serving certificate is required when the API server connects to the kubelet. Any operation that contacts the Kubelet endpoint requires this certificate approval to be in place. The method must watch for new CSRs, confirm that the CSR was submitted by the node-bootstrapper service account in the system:node or system:admin groups, and confirm the identity of the node.
- To approve them individually, run the following command for each valid CSR:
```
$ oc adm certificate approve <csr_name> 1
```
  1
  <csr_name> is the name of a CSR from the list of current CSRs.
- To approve all pending CSRs, run the following command:
```
$ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs --no-run-if-empty oc adm certificate approve
```
  Note
  Some Operators might not become available until some CSRs are approved.

Now that your client requests are approved, you must review the server requests for each machine that you added to the cluster:

$ oc get csr

Example output

NAME        AGE     REQUESTOR                                                                   CONDITION
csr-bfd72   5m26s   system:node:ip-10-0-50-126.us-east-2.compute.internal                       Pending
csr-c57lv   5m26s   system:node:ip-10-0-95-157.us-east-2.compute.internal                       Pending
...

If the remaining CSRs are not approved, and are in the Pending status, approve the CSRs for your cluster machines:
- To approve them individually, run the following command for each valid CSR:
```
$ oc adm certificate approve <csr_name> 1
```
  1
  <csr_name> is the name of a CSR from the list of current CSRs.
- To approve all pending CSRs, run the following command:
```
$ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve
```

After all client and server CSRs have been approved, the machines have the Ready status. Verify this by running the following command:

$ oc get nodes

Example output

NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  73m  v1.20.0
master-1  Ready     master  73m  v1.20.0
master-2  Ready     master  74m  v1.20.0
worker-0  Ready     worker  11m  v1.20.0
worker-1  Ready     worker  11m  v1.20.0

Note

It can take a few minutes after approval of the server CSRs for the machines to transition to the Ready status.

Additional information

For more information on CSRs, see Certificate Signing Requests.

10.1.16. Initial Operator configuration

After the control plane initializes, you must immediately configure some Operators so that they all become available.

Prerequisites

Your control plane has initialized.

Procedure

Watch the cluster components come online:

$ watch -n5 oc get clusteroperators

Example output

NAME                                       VERSION AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.7.0   True        False         False      3h56m
baremetal                                  4.7.0   True        False         False      29h
cloud-credential                           4.7.0   True        False         False      29h
cluster-autoscaler                         4.7.0   True        False         False      29h
config-operator                            4.7.0   True        False         False      6h39m
console                                    4.7.0   True        False         False      3h59m
csi-snapshot-controller                    4.7.0   True        False         False      4h12m
dns                                        4.7.0   True        False         False      4h15m
etcd                                       4.7.0   True        False         False      29h
image-registry                             4.7.0   True        False         False      3h59m
ingress                                    4.7.0   True        False         False      4h30m
insights                                   4.7.0   True        False         False      29h
kube-apiserver                             4.7.0   True        False         False      29h
kube-controller-manager                    4.7.0   True        False         False      29h
kube-scheduler                             4.7.0   True        False         False      29h
kube-storage-version-migrator              4.7.0   True        False         False      4h2m
machine-api                                4.7.0   True        False         False      29h
machine-approver                           4.7.0   True        False         False      6h34m
machine-config                             4.7.0   True        False         False      3h56m
marketplace                                4.7.0   True        False         False      4h2m
monitoring                                 4.7.0   True        False         False      6h31m
network                                    4.7.0   True        False         False      29h
node-tuning                                4.7.0   True        False         False      4h30m
openshift-apiserver                        4.7.0   True        False         False      3h56m
openshift-controller-manager               4.7.0   True        False         False      4h36m
openshift-samples                          4.7.0   True        False         False      4h30m
operator-lifecycle-manager                 4.7.0   True        False         False      29h
operator-lifecycle-manager-catalog         4.7.0   True        False         False      29h
operator-lifecycle-manager-packageserver   4.7.0   True        False         False      3h59m
service-ca                                 4.7.0   True        False         False      29h
storage                                    4.7.0   True        False         False      4h30m

Configure the Operators that are not available.

10.1.16.1. Image registry storage configuration

The Image Registry Operator is not initially available for platforms that do not provide default storage. After installation, you must configure your registry to use storage so that the Registry Operator is made available.

Instructions are shown for configuring a persistent volume, which is required for production clusters. Where applicable, instructions are shown for configuring an empty directory as the storage location, which is available for only non-production clusters.

Additional instructions are provided for allowing the image registry to use block storage types by using the Recreate rollout strategy during upgrades.

10.1.16.1.1. Configuring registry storage for IBM Z

As a cluster administrator, following installation you must configure your registry to use storage.

Prerequisites

Cluster administrator permissions.
A cluster on IBM Z.
Persistent storage provisioned for your cluster.
Important
OpenShift Container Platform supports ReadWriteOnce access for image registry storage when you have only one replica. To deploy an image registry that supports high availability with two or more replicas, ReadWriteMany access is required.
Must have 100Gi capacity.

Procedure

To configure your registry to use storage, change the spec.storage.pvc in the configs.imageregistry/cluster resource.
Note
When using shared storage, review your security settings to prevent outside access.
Verify that you do not have a registry pod:
```
$ oc get pod -n openshift-image-registry -l docker-registry=default
```
Example output
```
No resourses found in openshift-image-registry namespace
```
Note
If you do have a registry pod in your output, you do not need to continue with this procedure.
Check the registry configuration:
```
$ oc edit configs.imageregistry.operator.openshift.io
```
Example output
```
storage:
  pvc:
    claim:
```
Leave the claim field blank to allow the automatic creation of an image-registry-storage PVC.

Check the clusteroperator status:

$ oc get clusteroperator image-registry

Example output

NAME             VERSION                              AVAILABLE   PROGRESSING   DEGRADED   SINCE   MESSAGE
image-registry   4.7                                  True        False         False      6h50m

Ensure that your registry is set to managed to enable building and pushing of images.
- Run:
```
$ oc edit configs.imageregistry/cluster
```
  Then, change the line
```
managementState: Removed
```
  to
```
managementState: Managed
```

10.1.16.1.2. Configuring storage for the image registry in non-production clusters

You must configure storage for the Image Registry Operator. For non-production clusters, you can set the image registry to an empty directory. If you do so, all images are lost if you restart the registry.

Procedure

To set the image registry storage to an empty directory:
```
$ oc patch configs.imageregistry.operator.openshift.io cluster --type merge --patch '{"spec":{"storage":{"emptyDir":{}}}}'
```
Warning
Configure this option for only non-production clusters.
If you run this command before the Image Registry Operator initializes its components, the oc patch command fails with the following error:
```
Error from server (NotFound): configs.imageregistry.operator.openshift.io "cluster" not found
```
Wait a few minutes and run the command again.

10.1.17. Completing installation on user-provisioned infrastructure

After you complete the Operator configuration, you can finish installing the cluster on infrastructure that you provide.

Prerequisites

Your control plane has initialized.
You have completed the initial Operator configuration.

Procedure

Confirm that all the cluster components are online with the following command:

$ watch -n5 oc get clusteroperators

Example output

NAME                                       VERSION AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.7.0   True        False         False      3h56m
baremetal                                  4.7.0   True        False         False      29h
cloud-credential                           4.7.0   True        False         False      29h
cluster-autoscaler                         4.7.0   True        False         False      29h
config-operator                            4.7.0   True        False         False      6h39m
console                                    4.7.0   True        False         False      3h59m
csi-snapshot-controller                    4.7.0   True        False         False      4h12m
dns                                        4.7.0   True        False         False      4h15m
etcd                                       4.7.0   True        False         False      29h
image-registry                             4.7.0   True        False         False      3h59m
ingress                                    4.7.0   True        False         False      4h30m
insights                                   4.7.0   True        False         False      29h
kube-apiserver                             4.7.0   True        False         False      29h
kube-controller-manager                    4.7.0   True        False         False      29h
kube-scheduler                             4.7.0   True        False         False      29h
kube-storage-version-migrator              4.7.0   True        False         False      4h2m
machine-api                                4.7.0   True        False         False      29h
machine-approver                           4.7.0   True        False         False      6h34m
machine-config                             4.7.0   True        False         False      3h56m
marketplace                                4.7.0   True        False         False      4h2m
monitoring                                 4.7.0   True        False         False      6h31m
network                                    4.7.0   True        False         False      29h
node-tuning                                4.7.0   True        False         False      4h30m
openshift-apiserver                        4.7.0   True        False         False      3h56m
openshift-controller-manager               4.7.0   True        False         False      4h36m
openshift-samples                          4.7.0   True        False         False      4h30m
operator-lifecycle-manager                 4.7.0   True        False         False      29h
operator-lifecycle-manager-catalog         4.7.0   True        False         False      29h
operator-lifecycle-manager-packageserver   4.7.0   True        False         False      3h59m
service-ca                                 4.7.0   True        False         False      29h
storage                                    4.7.0   True        False         False      4h30m

Alternatively, the following command notifies you when all of the clusters are available. It also retrieves and displays credentials:

$ ./openshift-install --dir <installation_directory> wait-for install-complete 1

1: For <installation_directory>, specify the path to the directory that you stored the installation files in.

Example output

INFO Waiting up to 30m0s for the cluster to initialize...

The command succeeds when the Cluster Version Operator finishes deploying the OpenShift Container Platform cluster from Kubernetes API server.

Important

The Ignition config files that the installation program generates contain certificates that expire after 24 hours, which are then renewed at that time. If the cluster is shut down before renewing the certificates and the cluster is later restarted after the 24 hours have elapsed, the cluster automatically recovers the expired certificates. The exception is that you must manually approve the pending node-bootstrapper certificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information.
It is recommended that you use Ignition config files within 12 hours after they are generated because the 24-hour certificate rotates from 16 to 22 hours after the cluster is installed. By using the Ignition config files within 12 hours, you can avoid installation failure if the certificate update runs during installation.

Confirm that the Kubernetes API server is communicating with the pods.

To view a list of all pods, use the following command:

$ oc get pods --all-namespaces

Example output

NAMESPACE                         NAME                                            READY   STATUS      RESTARTS   AGE
openshift-apiserver-operator      openshift-apiserver-operator-85cb746d55-zqhs8   1/1     Running     1          9m
openshift-apiserver               apiserver-67b9g                                 1/1     Running     0          3m
openshift-apiserver               apiserver-ljcmx                                 1/1     Running     0          1m
openshift-apiserver               apiserver-z25h4                                 1/1     Running     0          2m
openshift-authentication-operator authentication-operator-69d5d8bf84-vh2n8        1/1     Running     0          5m
...

View the logs for a pod that is listed in the output of the previous command by using the following command:
```
$ oc logs <pod_name> -n <namespace> 1
```
1
Specify the pod name and namespace, as shown in the output of the previous command.
If the pod logs display, the Kubernetes API server can communicate with the cluster machines.

For an installation with Fibre Channel Protocol (FCP), additional steps are required to enable multipathing. Do not enable multipathing during installation.
See "Enabling multipathing with kernel arguments on RHCOS" in the Post-installation configuration documentation for more information.
1. All the worker nodes are restarted. To monitor the process, enter the following command:
```
$ oc get nodes -w
```
  Note
  If you have additional machine types such as infrastructure nodes, repeat the process for these types.

10.1.18. Telemetry access for OpenShift Container Platform

In OpenShift Container Platform 4.7, the Telemetry service, which runs by default to provide metrics about cluster health and the success of updates, requires internet access. If your cluster is connected to the internet, Telemetry runs automatically, and your cluster is registered to OpenShift Cluster Manager.

After you confirm that your OpenShift Cluster Manager inventory is correct, either maintained automatically by Telemetry or manually by using OpenShift Cluster Manager, use subscription watch to track your OpenShift Container Platform subscriptions at the account or multi-cluster level.

Additional resources

See About remote health monitoring for more information about the Telemetry service

10.1.19. Collecting debugging information

You can gather debugging information that might help you to troubleshoot and debug certain issues with an OpenShift Container Platform installation on IBM Z.

Prerequisites

The oc CLI tool installed.

Procedure

Log in to the cluster:
```
$ oc login -u <username>
```
On the node you want to gather hardware information about, start a debugging container:
```
$ oc debug node/<nodename>
```
Change to the /host file system and start toolbox:
```
$ chroot /host
$ toolbox
```
Collect the dbginfo data:
```
$ dbginfo.sh
```
You can then retrieve the data, for example, using scp.

Additional resources

See also How to generate SOSREPORT within OpenShift4 nodes without SSH.

10.1.20. Next steps

Customize your cluster.
If necessary, you can opt out of remote health reporting.

10.2. Installing a cluster with RHEL KVM on IBM Z and LinuxONE in a restricted network

In OpenShift Container Platform version 4.7, you can install a cluster on IBM Z and LinuxONE infrastructure that you provision in a restricted network.

Note

While this document refers to only IBM Z, all information in it also applies to LinuxONE.

Important

10.2.1. Prerequisites

Create a registry on your mirror host and obtain the imageContentSources data for your version of OpenShift Container Platform.
Move or remove any existing installation files, before you begin the installation process. This ensures that the required installation files are created and updated during the installation process.
Important
Ensure that installation steps are done from a machine with access to the installation media.
* You provisioned persistent storage using NFS for your cluster. To deploy a private image registry, you must set up persistent storage with ReadWriteMany access.
Review details about the OpenShift Container Platform installation and update processes.
If you use a firewall, you must configure it to allow the sites that your cluster requires access to.
You provisioned a RHEL Kernel Virtual Machine (KVM) system that is hosted on the logical partition (LPAR) and based on RHEL 8.4 or later.
Note
Be sure to also review this site list if you are configuring a proxy.

10.2.2. About installations in restricted networks

In OpenShift Container Platform 4.7, you can perform an installation that does not require an active connection to the Internet to obtain software components. Restricted network installations can be completed using installer-provisioned infrastructure or user-provisioned infrastructure, depending on the cloud platform to which you are installing the cluster.

If you choose to perform a restricted network installation on a cloud platform, you still require access to its cloud APIs. Some cloud functions, like Amazon Web Service’s Route 53 DNS and IAM services, require internet access. Depending on your network, you might require less Internet access for an installation on bare metal hardware or on VMware vSphere.

To complete a restricted network installation, you must create a registry that mirrors the contents of the OpenShift Container Platform registry and contains the installation media. You can create this registry on a mirror host, which can access both the Internet and your closed network, or by using other methods that meet your restrictions.

Important

Because of the complexity of the configuration for user-provisioned installations, consider completing a standard user-provisioned infrastructure installation before you attempt a restricted network installation using user-provisioned infrastructure. Completing this test installation might make it easier to isolate and troubleshoot any issues that might arise during your installation in a restricted network.

10.2.2.1. Additional limits

Clusters in restricted networks have the following additional limitations and restrictions:

The ClusterVersion status includes an Unable to retrieve available updates error.
By default, you cannot use the contents of the Developer Catalog because you cannot access the required image stream tags.

10.2.3. Machine requirements for a cluster with user-provisioned infrastructure

For a cluster that contains user-provisioned infrastructure, you must deploy all of the required machines.

One or more KVM host machines based on RHEL 8.4 or later. Each RHEL KVM host machine must have libvirt installed and running. The virtual machines are provisioned under each RHEL KVM host machine.

10.2.3.1. Required machines

The smallest OpenShift Container Platform clusters require the following nodes:

One temporary bootstrap machine
Three control plane, or master, machines
At least two compute machines, which are also known as worker machines

Note

The cluster requires the bootstrap machine to deploy the OpenShift Container Platform cluster on the three control plane machines. You can remove the bootstrap machine after you install the cluster.

Important

To improve high availability of your cluster, distribute the control plane machines over different RHEL instances on at least two physical machines.

The bootstrap, control plane, and compute machines must use Red Hat Enterprise Linux CoreOS (RHCOS) as the operating system.

See Red Hat Enterprise Linux technology capabilities and limits.

10.2.3.2. Network connectivity requirements

10.2.3.3. IBM Z network connectivity requirements

To install on IBM Z under RHEL KVM, you need:

A RHEL KVM host configured with an OSA or RoCE network adapter.
Either a RHEL KVM host that is configured to use bridged networking in libvirt or MacVTap to connect the network to the guests.
See Types of virtual network connections.

10.2.3.4. Host machine resource requirements

You can install OpenShift Container Platform version 4.7 on the following IBM hardware:

IBM z15 (all models), IBM z14 (all models), IBM z13, and IBM z13s
LinuxONE, any version

10.2.3.5. Minimum IBM Z system environment

Hardware requirements

The equivalent of six IFLs, which are SMT2 enabled, for each cluster.
At least one network connection to both connect to the LoadBalancer service and to serve data for traffic outside the cluster.

Note

Important

Operating system requirements

One LPAR running RHEL 8.4 or later with KVM, which is managed by libvirt

On your RHEL KVM host, set up:

Three guest virtual machines for OpenShift Container Platform control plane machines
Two guest virtual machines for OpenShift Container Platform compute machines
One guest virtual machine for the temporary OpenShift Container Platform bootstrap machine

10.2.3.6. Minimum resource requirements

Each cluster virtual machine must meet the following minimum requirements:

Virtual Machine	Operating System	vCPU ^[1]	Virtual RAM	Storage	IOPS
Bootstrap	RHCOS	4	16 GB	100 GB	N/A
Control plane	RHCOS	4	16 GB	100 GB	N/A
Compute	RHCOS	2	8 GB	100 GB	N/A

One physical core (IFL) provides two logical cores (threads) when SMT-2 is enabled. The hypervisor can provide two or more vCPUs.

10.2.3.7. Preferred IBM Z system environment

Hardware requirements

Three LPARS that each have the equivalent of six IFLs, which are SMT2 enabled, for each cluster.
Two network connections to connect to both connect to the LoadBalancer service and to serve data for traffic outside the cluster.

Operating system requirements

For high availability, two or three LPARs running RHEL 8.4 or later with KVM, which are managed by libvirt.

On your RHEL KVM host, set up:

Three guest virtual machines for OpenShift Container Platform control plane machines, distributed across the RHEL KVM host machines.
At least six guest virtual machines for OpenShift Container Platform compute machines, distributed across the RHEL KVM host machines.
One guest virtual machine for the temporary OpenShift Container Platform bootstrap machine.
To ensure the availability of integral components in an overcommitted environment, increase the priority of the control plane by using cpu_shares. Do the same for infrastructure nodes, if they exist. See schedinfo in IBM Documentation.

10.2.3.8. Preferred resource requirements

The preferred requirements for each cluster virtual machine are:

Virtual Machine	Operating System	vCPU	Virtual RAM	Storage
Bootstrap	RHCOS	4	16 GB	120 GB
Control plane	RHCOS	8	16 GB	120 GB
Compute	RHCOS	6	8 GB	120 GB

10.2.3.9. Certificate signing requests management

10.2.4. Internet access for OpenShift Container Platform

In OpenShift Container Platform 4.7, you require access to the Internet to obtain the images that are necessary to install your cluster.

You must have Internet access to:

Access OpenShift Cluster Manager to download the installation program and perform subscription management. If the cluster has internet access and you do not disable Telemetry, that service automatically entitles your cluster.
Access Quay.io to obtain the packages that are required to install your cluster.
Obtain the packages that are required to perform cluster updates.

Important

Additional resources

Recommended host practices for IBM Z & LinuxONE environments

10.2.5. Creating the user-provisioned infrastructure

Before you deploy an OpenShift Container Platform cluster that uses user-provisioned infrastructure, you must create the underlying infrastructure.

Prerequisites

Review the OpenShift Container Platform 4.x Tested Integrations page before you create the supporting infrastructure for your cluster.

Procedure

Set up static IP addresses.
Set up an HTTP or HTTPS server to provide Ignition files to the cluster nodes.
Choose to perform either a fast track installation of Red Hat Enterprise Linux CoreOS (RHCOS) or a full installation of Red Hat Enterprise Linux CoreOS (RHCOS). For the full installation you must set up an HTTP or HTTPS server to provide Ignition files and install images to the cluster nodes. For the fast track installation an HTTP or HTTPS server is not required, however, a DHCP server is required. See sections “Fast-track installation: Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines" and “Full installation: Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines".
Provision the required load balancers.
Configure the ports for your machines.
Configure DNS.
Ensure network connectivity.

10.2.5.1. Networking requirements for user-provisioned infrastructure

All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require network in initramfs during boot to fetch Ignition config from the machine config server.

During the initial boot, the machines require an HTTP or HTTPS server to establish a network connection to download their Ignition config files.

Ensure that the machines have persistent IP addresses and host names.

You must configure the network connectivity between machines to allow cluster components to communicate. Each machine must be able to resolve the host names of all other machines in the cluster.

Table 10.7. All machines to all machines
Protocol	Port	Description
ICMP	N/A	Network reachability tests
TCP	`1936`	Metrics
	`9000`-`9999`	Host level services, including the node exporter on ports `9100`-`9101` and the Cluster Version Operator on port `9099`.
	`10250`-`10259`	The default ports that Kubernetes reserves
	`10256`	openshift-sdn
UDP	`4789`	VXLAN and Geneve
	`6081`	VXLAN and Geneve
	`9000`-`9999`	Host level services, including the node exporter on ports `9100`-`9101`.
TCP/UDP	`30000`-`32767`	Kubernetes node port

Table 10.8. All machines to control plane
Protocol	Port	Description
TCP	`6443`	Kubernetes API

Table 10.9. Control plane machines to control plane machines
Protocol	Port	Description
TCP	`2379`-`2380`	etcd server and peer ports

Network topology requirements

The infrastructure that you provision for your cluster must meet the following network topology requirements.

Important

OpenShift Container Platform requires all nodes to have internet access to pull images for platform containers and provide telemetry data to Red Hat.

Load balancers

Before you install OpenShift Container Platform, you must provision two load balancers that meet the following requirements:

API load balancer: Provides a common endpoint for users, both human and machine, to interact with and configure the platform. Configure the following conditions:

Layer 4 load balancing only. This can be referred to as Raw TCP, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the API routes.
A stateless load balancing algorithm. The options vary based on the load balancer implementation.

Important

Do not configure session persistence for an API load balancer.

Configure the following ports on both the front and back of the load balancers:

Table 10.10. API load balancer
Port	Back-end machines (pool members)	Internal	External	Description
`6443`	Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane. You must configure the `/readyz` endpoint for the API server health check probe.	X	X	Kubernetes API server
`22623`	Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane.	X		Machine config server

Note

Application Ingress load balancer: Provides an Ingress point for application traffic flowing in from outside the cluster. Configure the following conditions:

Layer 4 load balancing only. This can be referred to as Raw TCP, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the Ingress routes.
A connection-based or session-based persistence is recommended, based on the options available and types of applications that will be hosted on the platform.

Configure the following ports on both the front and back of the load balancers:

Table 10.11. Application Ingress load balancer
Port	Back-end machines (pool members)	Internal	External	Description
`443`	The machines that run the Ingress router pods, compute, or worker, by default.	X	X	HTTPS traffic
`80`	The machines that run the Ingress router pods, compute, or worker, by default.	X	X	HTTP traffic

Tip

If the true IP address of the client can be seen by the load balancer, enabling source IP-based session persistence can improve performance for applications that use end-to-end TLS encryption.

Note

A working configuration for the Ingress router is required for an OpenShift Container Platform cluster. You must configure the Ingress router after the control plane initializes.

NTP configuration

Additional resources

Configuring chrony time service

10.2.5.2. User-provisioned DNS requirements

Table 10.12. Required DNS records
Component	Record	Description
Kubernetes API	`api.<cluster_name>.<base_domain>.`	Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.
Kubernetes API	`api-int.<cluster_name>.<base_domain>.`	Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. These records must be resolvable from all the nodes within the cluster. Important The API server must be able to resolve the worker nodes by the host names that are recorded in Kubernetes. If the API server cannot resolve the node names, then proxied API calls can fail, and you cannot retrieve logs from pods.
Routes	`*.apps.<cluster_name>.<base_domain>.`	Add a wildcard DNS A/AAAA or CNAME record that refers to the load balancer that targets the machines that run the Ingress router pods, which are the worker nodes by default. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.
Bootstrap	`bootstrap.<cluster_name>.<base_domain>.`	Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the bootstrap machine. These records must be resolvable by the nodes within the cluster.
Master hosts	`<master><n>.<cluster_name>.<base_domain>.`	DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the control plane nodes (also known as the master nodes). These records must be resolvable by the nodes within the cluster.
Worker hosts	`<worker><n>.<cluster_name>.<base_domain>.`	Add DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the worker nodes. These records must be resolvable by the nodes within the cluster.

Tip

You can use the nslookup <hostname> command to verify name resolution. You can use the dig -x <ip_address> command to verify reverse name resolution for the PTR records.

Example 10.3. Sample DNS zone database

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
	IN	MX 10	smtp.example.com.
;
;
ns1	IN	A	192.168.1.5
smtp	IN	A	192.168.1.5
;
helper	IN	A	192.168.1.5
helper.ocp4	IN	A	192.168.1.5
;
; The api identifies the IP of your load balancer.
api.ocp4		IN	A	192.168.1.5
api-int.ocp4		IN	A	192.168.1.5
;
; The wildcard also identifies the load balancer.
*.apps.ocp4		IN	A	192.168.1.5
;
; Create an entry for the bootstrap host.
bootstrap.ocp4	IN	A	192.168.1.96
;
; Create entries for the master hosts.
master0.ocp4		IN	A	192.168.1.97
master1.ocp4		IN	A	192.168.1.98
master2.ocp4		IN	A	192.168.1.99
;
; Create entries for the worker hosts.
worker0.ocp4		IN	A	192.168.1.11
worker1.ocp4		IN	A	192.168.1.7
;
;EOF

The following example BIND zone file shows sample PTR records for reverse name resolution.

Example 10.4. Sample DNS zone database for reverse records

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
;
; The syntax is "last octet" and the host must have an FQDN
; with a trailing dot.
97	IN	PTR	master0.ocp4.example.com.
98	IN	PTR	master1.ocp4.example.com.
99	IN	PTR	master2.ocp4.example.com.
;
96	IN	PTR	bootstrap.ocp4.example.com.
;
5	IN	PTR	api.ocp4.example.com.
5	IN	PTR	api-int.ocp4.example.com.
;
11	IN	PTR	worker0.ocp4.example.com.
7	IN	PTR	worker1.ocp4.example.com.
;
;EOF

10.2.6. Generating an SSH private key and adding it to the agent

Note

In a production environment, you require disaster recovery and debugging.

Important

Do not skip this procedure in production environments where disaster recovery and debugging is required.

You can use this key to SSH into the master nodes as the user core. When you deploy the cluster, the key is added to the core user’s ~/.ssh/authorized_keys list.

Procedure

If you do not have an SSH key that is configured for password-less authentication on your computer, create one. For example, on a computer that uses a Linux operating system, run the following command:
```
$ ssh-keygen -t ed25519 -N '' \
    -f <path>/<file_name> 1
```
1
Specify the path and file name, such as ~/.ssh/id_rsa, of the new SSH key. If you have an existing key pair, ensure your public key is in the your ~/.ssh directory.
Running this command generates an SSH key that does not require a password in the location that you specified.
Note
If you plan to install an OpenShift Container Platform cluster that uses FIPS Validated / Modules in Process cryptographic libraries on the x86_64 architecture, do not create a key that uses the ed25519 algorithm. Instead, create a key that uses the rsa or ecdsa algorithm.
Start the ssh-agent process as a background task:
```
$ eval "$(ssh-agent -s)"
```
Example output
```
Agent pid 31874
```
Note
If your cluster is in FIPS mode, only use FIPS-compliant algorithms to generate the SSH key. The key must be either RSA or ECDSA.
Add your SSH private key to the ssh-agent:
```
$ ssh-add <path>/<file_name> 1
```
Example output
```
Identity added: /home/<you>/<path>/<file_name> (<computer_name>)
```
1
Specify the path and file name for your SSH private key, such as ~/.ssh/id_rsa

Next steps

When you install OpenShift Container Platform, provide the SSH public key to the installation program.

10.2.7. Manually creating the installation configuration file

For installations of OpenShift Container Platform that use user-provisioned infrastructure, you manually generate your installation configuration file.

Prerequisites

Obtain the OpenShift Container Platform installation program and the access token for your cluster.

Procedure

Create an installation directory to store your required installation assets in:
```
$ mkdir <installation_directory>
```
Important
You must create a directory. Some installation assets, like bootstrap X.509 certificates have short expiration intervals, so you must not reuse an installation directory. If you want to reuse individual files from another cluster installation, you can copy them into your directory. However, the file names for the installation assets might change between releases. Use caution when copying installation files from an earlier OpenShift Container Platform version.
Customize the following install-config.yaml file template and save it in the <installation_directory>.
Note
You must name this configuration file install-config.yaml.
Back up the install-config.yaml file so that you can use it to install multiple clusters.
Important
The install-config.yaml file is consumed during the next step of the installation process. You must back it up now.

10.2.7.1. Sample install-config.yaml file for IBM Z

You can customize the install-config.yaml file to specify more details about your OpenShift Container Platform cluster’s platform or modify the values of the required parameters.

apiVersion: v1
baseDomain: example.com 1
compute: 2
- hyperthreading: Enabled 3
  name: worker
  replicas: 0 4
  architecture : s390x
controlPlane: 5
  hyperthreading: Enabled 6
  name: master
  replicas: 3 7
  architecture : s390x
metadata:
  name: test 8
networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14 9
    hostPrefix: 23 10
  networkType: OpenShiftSDN
  serviceNetwork: 11
  - 172.30.0.0/16
platform:
  none: {} 12
fips: false 13
pullSecret: '{"auths":{"<local_registry>": {"auth": "<credentials>","email": "you@example.com"}}}' 14
sshKey: 'ssh-ed25519 AAAA...' 15
additionalTrustBundle: | 16
  -----BEGIN CERTIFICATE-----
  ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
  -----END CERTIFICATE-----
imageContentSources: 17
- mirrors:
  - <local_repository>/ocp4/openshift4
  source: quay.io/openshift-release-dev/ocp-release
- mirrors:
  - <local_repository>/ocp4/openshift4
  source: quay.io/openshift-release-dev/ocp-v4.0-art-dev

1

The base domain of the cluster. All DNS records must be sub-domains of this base and include the cluster name.

2 5

3 6

Note

Simultaneous multithreading (SMT) is enabled by default. If SMT is not enabled in your BIOS settings, the hyperthreading parameter has no effect.

Important

If you disable hyperthreading, whether in the BIOS or in the install-config.yaml, ensure that your capacity planning accounts for the dramatically decreased machine performance.

4

7

8

The cluster name that you specified in your DNS records.

9

Note

Class E CIDR range is reserved for a future use. To use the Class E CIDR range, you must ensure your networking environment accepts the IP addresses within the Class E CIDR range.

10

11

12

You must set the platform to none. You cannot provide additional platform configuration variables for IBM Z infrastructure.

Warning

There will be no cluster provider so you must manually add each machine and there will be no node scaling capabilities.
The oVirt CSI driver will not be installed and there will be no CSI capabilities.

13

Important

The use of FIPS Validated / Modules in Process cryptographic libraries is only supported on OpenShift Container Platform deployments on the x86_64 architecture.

14

For <local_registry>, specify the registry domain name, and optionally the port, that your mirror registry uses to serve content. For example, registry.example.com or registry.example.com:5000. For <credentials>, specify the base64-encoded user name and password for your mirror registry.

15

The public portion of the default SSH key for the core user in Red Hat Enterprise Linux CoreOS (RHCOS).

Note

For production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your ssh-agent process uses.

16

Add the additionalTrustBundle parameter and value. The value must be the contents of the certificate file that you used for your mirror registry, which can be an existing, trusted certificate authority or the self-signed certificate that you generated for the mirror registry.

17

Provide the imageContentSources section from the output of the command to mirror the repository.

10.2.7.2. Configuring the cluster-wide proxy during installation

Prerequisites

You have an existing install-config.yaml file.
You reviewed the sites that your cluster requires access to and determined whether any of them need to bypass the proxy. By default, all cluster egress traffic is proxied, including calls to hosting cloud provider APIs. You added sites to the Proxy object’s spec.noProxy field to bypass the proxy if necessary.
Note
The Proxy object status.noProxy field is populated with the values of the networking.machineNetwork[].cidr, networking.clusterNetwork[].cidr, and networking.serviceNetwork[] fields from your installation configuration.
For installations on Amazon Web Services (AWS), Google Cloud Platform (GCP), Microsoft Azure, and Red Hat OpenStack Platform (RHOSP), the Proxy object status.noProxy field is also populated with the instance metadata endpoint (169.254.169.254).

Procedure

Edit your install-config.yaml file and add the proxy settings. For example:
```
apiVersion: v1
baseDomain: my.domain.com
proxy:
  httpProxy: http://<username>:<pswd>@<ip>:<port> 1
  httpsProxy: https://<username>:<pswd>@<ip>:<port> 2
  noProxy: example.com 3
additionalTrustBundle: | 4
    -----BEGIN CERTIFICATE-----
    <MY_TRUSTED_CA_CERT>
    -----END CERTIFICATE-----
...
```
1
A proxy URL to use for creating HTTP connections outside the cluster. The URL scheme must be http.
2
A proxy URL to use for creating HTTPS connections outside the cluster.
3
A comma-separated list of destination domain names, IP addresses, or other network CIDRs to exclude from proxying. Preface a domain with . to match subdomains only. For example, .y.com matches x.y.com, but not y.com. Use * to bypass the proxy for all destinations.
4
If provided, the installation program generates a config map that is named user-ca-bundle in the openshift-config namespace to hold the additional CA certificates. If you provide additionalTrustBundle and at least one proxy setting, the Proxy object is configured to reference the user-ca-bundle config map in the trustedCA field. The Cluster Network Operator then creates a trusted-ca-bundle config map that merges the contents specified for the trustedCA parameter with the RHCOS trust bundle. The additionalTrustBundle field is required unless the proxy’s identity certificate is signed by an authority from the RHCOS trust bundle.
Note
The installation program does not support the proxy readinessEndpoints field.
Save the file and reference it when installing OpenShift Container Platform.

Note

Only the Proxy object named cluster is supported, and no additional proxies can be created.

10.2.8. Creating the Kubernetes manifest and Ignition config files

The installation configuration file transforms into the Kubernetes manifests. The manifests wrap into the Ignition configuration files, which are later used to create the cluster.

Important

Note

Prerequisites

You obtained the OpenShift Container Platform installation program. For a restricted network installation, these files are on your mirror host.
You created the install-config.yaml installation configuration file.

Procedure

Change to the directory that contains the installation program and generate the Kubernetes manifests for the cluster:
```
$ ./openshift-install create manifests --dir <installation_directory> 1
```
1
For <installation_directory>, specify the installation directory that contains the install-config.yaml file you created.
Warning
If you are installing a three-node cluster, skip the following step to allow the control plane nodes to be schedulable.
Important
When you configure control plane nodes from the default unschedulable to schedulable, additional subscriptions are required. This is because control plane nodes then become worker nodes.
Check that the mastersSchedulable parameter in the <installation_directory>/manifests/cluster-scheduler-02-config.yml Kubernetes manifest file is set to false. This setting prevents pods from being scheduled on the control plane machines:
1. Open the <installation_directory>/manifests/cluster-scheduler-02-config.yml file.
2. Locate the mastersSchedulable parameter and ensure that it is set to false.
3. Save and exit the file.
To create the Ignition configuration files, run the following command from the directory that contains the installation program:
```
$ ./openshift-install create ignition-configs --dir <installation_directory> 1
```
1
For <installation_directory>, specify the same installation directory.
The following files are generated in the directory:
```
.
├── auth
│   ├── kubeadmin-password
│   └── kubeconfig
├── bootstrap.ign
├── master.ign
├── metadata.json
└── worker.ign
```

10.2.9. Fast-track installation: Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines

Prerequisites

At least one LPAR running RHEL 8.4 with KVM, referred to as RHEL KVM host in this procedure.
The KVM/QEMU hypervisor is installed on the RHEL KVM host.
A domain name server (DNS) that can perform hostname and reverse lookup for the nodes.
A DHCP server that provides IP addresses.

Procedure

Obtain the RHEL QEMU copy-on-write (QCOW2) disk image file from the Product Downloads page on the Red Hat Customer Portal or from the RHCOS image mirror page.
Important
The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Only use the appropriate RHCOS QCOW2 image described in the following procedure.
Download the QCOW2 disk image and Ignition files to a common directory on the RHEL KVM host.
For example: /var/lib/libvirt/images
Note
The Ignition files are generated by the OpenShift Container Platform installer.

Create a new disk image with the QCOW2 disk image backing file for each KVM guest node.

$ qemu-img create -f qcow2 -F qcow2 -b /var/lib/libvirt/images/{source_rhcos_qemu} /var/lib/libvirt/images/{vmname}.qcow2 {size}

Create the new KVM guest nodes using the Ignition file and the new disk image.

$ virt-install --noautoconsole \
   --connect qemu:///system \
   --name {vn_name} \
   --memory {memory} \
   --vcpus {vcpus} \
   --disk {disk} \
   --import \
   --network network={network},mac={mac} \
   --qemu-commandline="-drive \
if=none,id=ignition,format=raw,file={ign_file},readonly=on -device virtio-blk,serial=ignition,drive=ignition"

10.2.10. Full installation: Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines

Before you install a cluster on IBM Z infrastructure that you provision, you must install RHCOS as Red Hat Enterprise Linux (RHEL) guest virtual machines for the cluster to use. Complete the following steps to create the machines in a full installation on a new QEMU copy-on-write (QCOW2) disk image.

Prerequisites

At least 1 LPAR running RHEL 8.3 with KVM, referred to as RHEL KVM host in this procedure.
The KVM/QEMU hypervisor is installed on the RHEL KVM host.
A domain name server (DNS) that can perform hostname and reverse lookup for the nodes.
An HTTP or HTTPS server is set up.

Procedure

Obtain the RHEL kernel, initramfs, and rootfs files from the Product Downloads page on the Red Hat Customer Portal or from the RHCOS image mirror page.
Important
The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Only use the appropriate RHCOS QCOW2 image described in the following procedure.
The file names contain the OpenShift Container Platform version number. They resemble the following examples:
- kernel: rhcos-<version>-live-kernel-<architecture>
- initramfs: rhcos-<version>-live-initramfs.<architecture>.img
- rootfs: rhcos-<version>-live-rootfs.<architecture>.img
Move the downloaded RHEL live kernel, initramfs, and rootfs as well as the Ignition files to an HTTP or HTTPS server before you launch virt-install.
Note
The Ignition files are generated by the OpenShift Container Platform installer.

Create the new KVM guest nodes using the RHEL kernel, initramfs, and Ignition files, the new disk image, and adjusted parm line arguments.

For --location, specify the location of the kernel/initrd on the HTTP or HTTPS server.
For coreos.inst.ignition_url=, specify the Ignition file for the machine role. Use bootstrap.ign, master.ign, or worker.ign. Only HTTP and HTTPS protocols are supported.

For coreos.live.rootfs_url=, specify the matching rootfs artifact for the kernel and initramfs you are booting. Only HTTP and HTTPS protocols are supported.

$ virt-install \
   --connect qemu:///system \
   --name {vn_name} \
   --vcpus {vcpus} \
   --memory {memory_mb} \
   --disk {vn_name}.qcow2,size={image_size| default(10,true)} \
   --network network={virt_network_parm} \
   --boot hd \
   --location {media_location},kernel={rhcos_kernel},initrd={rhcos_initrd} \
   --extra-args "rd.neednet=1 dfltcc=off coreos.inst=yes coreos.inst.install_dev=vda coreos.live.rootfs_url={rhcos_liveos} ip={ip}::{default_gateway}:{subnet_mask_length}:{vn_name}:enc1:none:{MTU} nameserver={dns} coreos.inst.ignition_url={rhcos_ign}" \
   --noautoconsole \
   --wait

Note

dfltcc=off is required for IBM z15 and LinuxONE III.

10.2.11. Creating the cluster

Prerequisites

Create the required infrastructure for the cluster.
You obtained the installation program and generated the Ignition config files for your cluster.
You used the Ignition config files to create RHCOS machines for your cluster.
Your machines have direct Internet access or have an HTTP or HTTPS proxy available.

Procedure

Monitor the bootstrap process:
```
$ ./openshift-install --dir <installation_directory> wait-for bootstrap-complete \ 1
    --log-level=info 2
```
1
For <installation_directory>, specify the path to the directory that you stored the installation files in.
2
To view different installation details, specify warn, debug, or error instead of info.
Example output
```
INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443...
INFO API v1.20.0 up
INFO Waiting up to 30m0s for bootstrapping to complete...
INFO It is now safe to remove the bootstrap resources
```
The command succeeds when the Kubernetes API server signals that it has been bootstrapped on the control plane machines.
After bootstrap process is complete, remove the bootstrap machine from the load balancer.
Important
You must remove the bootstrap machine from the load balancer at this point. You can also remove or reformat the machine itself.

10.2.12. Logging in to the cluster by using the CLI

Prerequisites

You deployed an OpenShift Container Platform cluster.
You installed the oc CLI.

Procedure

Export the kubeadmin credentials:
```
$ export KUBECONFIG=<installation_directory>/auth/kubeconfig 1
```
1
For <installation_directory>, specify the path to the directory that you stored the installation files in.
Verify you can run oc commands successfully using the exported configuration:
```
$ oc whoami
```
Example output
```
system:admin
```

10.2.13. Approving the certificate signing requests for your machines

Prerequisites

You added machines to your cluster.

Procedure

Confirm that the cluster recognizes the machines:
```
$ oc get nodes
```
Example output
```
NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  63m  v1.20.0
master-1  Ready     master  63m  v1.20.0
master-2  Ready     master  64m  v1.20.0
```
The output lists all of the machines that you created.
Note
The preceding output might not include the compute nodes, also known as worker nodes, until some CSRs are approved.

Review the pending CSRs and ensure that you see the client requests with the Pending or Approved status for each machine that you added to the cluster:

$ oc get csr

Example output

NAME        AGE   REQUESTOR                                   CONDITION
csr-mddf5   20m   system:node:master-01.example.com   Approved,Issued
csr-z5rln   16m   system:node:worker-21.example.com   Approved,Issued

If the CSRs were not approved, after all of the pending CSRs for the machines you added are in Pending status, approve the CSRs for your cluster machines:
Note
Because the CSRs rotate automatically, approve your CSRs within an hour of adding the machines to the cluster. If you do not approve them within an hour, the certificates will rotate, and more than two certificates will be present for each node. You must approve all of these certificates. Once the client CSR is approved, the Kubelet creates a secondary CSR for the serving certificate, which requires manual approval. Then, subsequent serving certificate renewal requests are automatically approved by the machine-approver if the Kubelet requests a new certificate with identical parameters.
Note
For clusters running on platforms that are not machine API enabled, such as bare metal and other user-provisioned infrastructure, you must implement a method of automatically approving the kubelet serving certificate requests (CSRs). If a request is not approved, then the oc exec, oc rsh, and oc logs commands cannot succeed, because a serving certificate is required when the API server connects to the kubelet. Any operation that contacts the Kubelet endpoint requires this certificate approval to be in place. The method must watch for new CSRs, confirm that the CSR was submitted by the node-bootstrapper service account in the system:node or system:admin groups, and confirm the identity of the node.
- To approve them individually, run the following command for each valid CSR:
```
$ oc adm certificate approve <csr_name> 1
```
  1
  <csr_name> is the name of a CSR from the list of current CSRs.
- To approve all pending CSRs, run the following command:
```
$ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs --no-run-if-empty oc adm certificate approve
```
  Note
  Some Operators might not become available until some CSRs are approved.

Now that your client requests are approved, you must review the server requests for each machine that you added to the cluster:

$ oc get csr

Example output

NAME        AGE     REQUESTOR                                                                   CONDITION
csr-bfd72   5m26s   system:node:ip-10-0-50-126.us-east-2.compute.internal                       Pending
csr-c57lv   5m26s   system:node:ip-10-0-95-157.us-east-2.compute.internal                       Pending
...

If the remaining CSRs are not approved, and are in the Pending status, approve the CSRs for your cluster machines:
- To approve them individually, run the following command for each valid CSR:
```
$ oc adm certificate approve <csr_name> 1
```
  1
  <csr_name> is the name of a CSR from the list of current CSRs.
- To approve all pending CSRs, run the following command:
```
$ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve
```

After all client and server CSRs have been approved, the machines have the Ready status. Verify this by running the following command:

$ oc get nodes

Example output

NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  73m  v1.20.0
master-1  Ready     master  73m  v1.20.0
master-2  Ready     master  74m  v1.20.0
worker-0  Ready     worker  11m  v1.20.0
worker-1  Ready     worker  11m  v1.20.0

Note

It can take a few minutes after approval of the server CSRs for the machines to transition to the Ready status.

Additional information

For more information on CSRs, see Certificate Signing Requests.

10.2.14. Initial Operator configuration

After the control plane initializes, you must immediately configure some Operators so that they all become available.

Prerequisites

Your control plane has initialized.

Procedure

Watch the cluster components come online:

$ watch -n5 oc get clusteroperators

Example output

NAME                                       VERSION AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.7.0   True        False         False      3h56m
baremetal                                  4.7.0   True        False         False      29h
cloud-credential                           4.7.0   True        False         False      29h
cluster-autoscaler                         4.7.0   True        False         False      29h
config-operator                            4.7.0   True        False         False      6h39m
console                                    4.7.0   True        False         False      3h59m
csi-snapshot-controller                    4.7.0   True        False         False      4h12m
dns                                        4.7.0   True        False         False      4h15m
etcd                                       4.7.0   True        False         False      29h
image-registry                             4.7.0   True        False         False      3h59m
ingress                                    4.7.0   True        False         False      4h30m
insights                                   4.7.0   True        False         False      29h
kube-apiserver                             4.7.0   True        False         False      29h
kube-controller-manager                    4.7.0   True        False         False      29h
kube-scheduler                             4.7.0   True        False         False      29h
kube-storage-version-migrator              4.7.0   True        False         False      4h2m
machine-api                                4.7.0   True        False         False      29h
machine-approver                           4.7.0   True        False         False      6h34m
machine-config                             4.7.0   True        False         False      3h56m
marketplace                                4.7.0   True        False         False      4h2m
monitoring                                 4.7.0   True        False         False      6h31m
network                                    4.7.0   True        False         False      29h
node-tuning                                4.7.0   True        False         False      4h30m
openshift-apiserver                        4.7.0   True        False         False      3h56m
openshift-controller-manager               4.7.0   True        False         False      4h36m
openshift-samples                          4.7.0   True        False         False      4h30m
operator-lifecycle-manager                 4.7.0   True        False         False      29h
operator-lifecycle-manager-catalog         4.7.0   True        False         False      29h
operator-lifecycle-manager-packageserver   4.7.0   True        False         False      3h59m
service-ca                                 4.7.0   True        False         False      29h
storage                                    4.7.0   True        False         False      4h30m

Configure the Operators that are not available.

10.2.14.1. Disabling the default OperatorHub sources

Operator catalogs that source content provided by Red Hat and community projects are configured for OperatorHub by default during an OpenShift Container Platform installation. In a restricted network environment, you must disable the default catalogs as a cluster administrator.

Procedure

Disable the sources for the default catalogs by adding disableAllDefaultSources: true to the OperatorHub object:

$ oc patch OperatorHub cluster --type json \
    -p '[{"op": "add", "path": "/spec/disableAllDefaultSources", "value": true}]'

Tip

Alternatively, you can use the web console to manage catalog sources. From the Administration Cluster Settings Global Configuration OperatorHub page, click the Sources tab, where you can create, delete, disable, and enable individual sources.

10.2.14.2. Image registry storage configuration

Additional instructions are provided for allowing the image registry to use block storage types by using the Recreate rollout strategy during upgrades.

10.2.14.2.1. Configuring registry storage for IBM Z

As a cluster administrator, following installation you must configure your registry to use storage.

Prerequisites

Cluster administrator permissions.
A cluster on IBM Z.
Persistent storage provisioned for your cluster.
Important
OpenShift Container Platform supports ReadWriteOnce access for image registry storage when you have only one replica. To deploy an image registry that supports high availability with two or more replicas, ReadWriteMany access is required.
Must have 100Gi capacity.

Procedure

To configure your registry to use storage, change the spec.storage.pvc in the configs.imageregistry/cluster resource.
Note
When using shared storage, review your security settings to prevent outside access.
Verify that you do not have a registry pod:
```
$ oc get pod -n openshift-image-registry -l docker-registry=default
```
Example output
```
No resourses found in openshift-image-registry namespace
```
Note
If you do have a registry pod in your output, you do not need to continue with this procedure.
Check the registry configuration:
```
$ oc edit configs.imageregistry.operator.openshift.io
```
Example output
```
storage:
  pvc:
    claim:
```
Leave the claim field blank to allow the automatic creation of an image-registry-storage PVC.

Check the clusteroperator status:

$ oc get clusteroperator image-registry

Example output

NAME             VERSION                              AVAILABLE   PROGRESSING   DEGRADED   SINCE   MESSAGE
image-registry   4.7                                  True        False         False      6h50m

Ensure that your registry is set to managed to enable building and pushing of images.
- Run:
```
$ oc edit configs.imageregistry/cluster
```
  Then, change the line
```
managementState: Removed
```
  to
```
managementState: Managed
```

10.2.14.2.2. Configuring storage for the image registry in non-production clusters

Procedure

To set the image registry storage to an empty directory:
```
$ oc patch configs.imageregistry.operator.openshift.io cluster --type merge --patch '{"spec":{"storage":{"emptyDir":{}}}}'
```
Warning
Configure this option for only non-production clusters.
If you run this command before the Image Registry Operator initializes its components, the oc patch command fails with the following error:
```
Error from server (NotFound): configs.imageregistry.operator.openshift.io "cluster" not found
```
Wait a few minutes and run the command again.

10.2.15. Completing installation on user-provisioned infrastructure

After you complete the Operator configuration, you can finish installing the cluster on infrastructure that you provide.

Prerequisites

Your control plane has initialized.
You have completed the initial Operator configuration.

Procedure

Confirm that all the cluster components are online with the following command:

$ watch -n5 oc get clusteroperators

Example output

NAME                                       VERSION AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.7.0   True        False         False      3h56m
baremetal                                  4.7.0   True        False         False      29h
cloud-credential                           4.7.0   True        False         False      29h
cluster-autoscaler                         4.7.0   True        False         False      29h
config-operator                            4.7.0   True        False         False      6h39m
console                                    4.7.0   True        False         False      3h59m
csi-snapshot-controller                    4.7.0   True        False         False      4h12m
dns                                        4.7.0   True        False         False      4h15m
etcd                                       4.7.0   True        False         False      29h
image-registry                             4.7.0   True        False         False      3h59m
ingress                                    4.7.0   True        False         False      4h30m
insights                                   4.7.0   True        False         False      29h
kube-apiserver                             4.7.0   True        False         False      29h
kube-controller-manager                    4.7.0   True        False         False      29h
kube-scheduler                             4.7.0   True        False         False      29h
kube-storage-version-migrator              4.7.0   True        False         False      4h2m
machine-api                                4.7.0   True        False         False      29h
machine-approver                           4.7.0   True        False         False      6h34m
machine-config                             4.7.0   True        False         False      3h56m
marketplace                                4.7.0   True        False         False      4h2m
monitoring                                 4.7.0   True        False         False      6h31m
network                                    4.7.0   True        False         False      29h
node-tuning                                4.7.0   True        False         False      4h30m
openshift-apiserver                        4.7.0   True        False         False      3h56m
openshift-controller-manager               4.7.0   True        False         False      4h36m
openshift-samples                          4.7.0   True        False         False      4h30m
operator-lifecycle-manager                 4.7.0   True        False         False      29h
operator-lifecycle-manager-catalog         4.7.0   True        False         False      29h
operator-lifecycle-manager-packageserver   4.7.0   True        False         False      3h59m
service-ca                                 4.7.0   True        False         False      29h
storage                                    4.7.0   True        False         False      4h30m

Alternatively, the following command notifies you when all of the clusters are available. It also retrieves and displays credentials:

$ ./openshift-install --dir <installation_directory> wait-for install-complete 1

1: For <installation_directory>, specify the path to the directory that you stored the installation files in.

Example output

INFO Waiting up to 30m0s for the cluster to initialize...

The command succeeds when the Cluster Version Operator finishes deploying the OpenShift Container Platform cluster from Kubernetes API server.

Important

The Ignition config files that the installation program generates contain certificates that expire after 24 hours, which are then renewed at that time. If the cluster is shut down before renewing the certificates and the cluster is later restarted after the 24 hours have elapsed, the cluster automatically recovers the expired certificates. The exception is that you must manually approve the pending node-bootstrapper certificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information.
It is recommended that you use Ignition config files within 12 hours after they are generated because the 24-hour certificate rotates from 16 to 22 hours after the cluster is installed. By using the Ignition config files within 12 hours, you can avoid installation failure if the certificate update runs during installation.

Confirm that the Kubernetes API server is communicating with the pods.

To view a list of all pods, use the following command:

$ oc get pods --all-namespaces

Example output

NAMESPACE                         NAME                                            READY   STATUS      RESTARTS   AGE
openshift-apiserver-operator      openshift-apiserver-operator-85cb746d55-zqhs8   1/1     Running     1          9m
openshift-apiserver               apiserver-67b9g                                 1/1     Running     0          3m
openshift-apiserver               apiserver-ljcmx                                 1/1     Running     0          1m
openshift-apiserver               apiserver-z25h4                                 1/1     Running     0          2m
openshift-authentication-operator authentication-operator-69d5d8bf84-vh2n8        1/1     Running     0          5m
...

View the logs for a pod that is listed in the output of the previous command by using the following command:
```
$ oc logs <pod_name> -n <namespace> 1
```
1
Specify the pod name and namespace, as shown in the output of the previous command.
If the pod logs display, the Kubernetes API server can communicate with the cluster machines.

For an installation with Fibre Channel Protocol (FCP), additional steps are required to enable multipathing. Do not enable multipathing during installation.
See "Enabling multipathing with kernel arguments on RHCOS" in the Post-installation configuration documentation for more information.
1. All the worker nodes are restarted. To monitor the process, enter the following command:
```
$ oc get nodes -w
```
  Note
  If you have additional machine types such as infrastructure nodes, repeat the process for these types.

10.2.16. Telemetry access for OpenShift Container Platform

Additional resources

See About remote health monitoring for more information about the Telemetry service

10.2.17. Collecting debugging information

You can gather debugging information that might help you to troubleshoot and debug certain issues with an OpenShift Container Platform installation on IBM Z.

Prerequisites

The oc CLI tool installed.

Procedure

Log in to the cluster:
```
$ oc login -u <username>
```
On the node you want to gather hardware information about, start a debugging container:
```
$ oc debug node/<nodename>
```
Change to the /host file system and start toolbox:
```
$ chroot /host
$ toolbox
```
Collect the dbginfo data:
```
$ dbginfo.sh
```
You can then retrieve the data, for example, using scp.

Additional resources

How to generate SOSREPORT within OpenShift Container Platform version 4 nodes without SSH.

10.2.18. Next steps

Customize your cluster.
If the mirror registry that you used to install your cluster has a trusted CA, add it to the cluster by configuring additional trust stores.