Installing on IBM Z and LinuxONE

OpenShift Container Platform 4.4

Installing OpenShift Container Platform IBM Z clusters

Red Hat OpenShift Documentation Team

Abstract

This document provides instructions for installing OpenShift Container Platform clusters on IBM Z.

Chapter 1. Installing on IBM Z

1.1. Installing a cluster on IBM Z and LinuxONE

In OpenShift Container Platform version 4.4, 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.

1.1.1. Prerequisites

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.
Note
Be sure to also review this site list if you are configuring a proxy.

1.1.2. Internet and Telemetry access for OpenShift Container Platform

In OpenShift Container Platform 4.4, you require access to the Internet to install your cluster. The Telemetry service, which runs by default to provide metrics about cluster health and the success of updates, also requires Internet access. If your cluster is connected to the Internet, Telemetry runs automatically, and your cluster is registered to the Red Hat OpenShift Cluster Manager (OCM).

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

You must have Internet access to:

Access the Red Hat OpenShift Cluster Manager page 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.

1.1.3. 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.

1.1.3.1. Required machines

The smallest OpenShift Container Platform clusters require the following hosts:

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 z/VM instances on at least two physical machines.

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

Note that RHCOS is based on Red Hat Enterprise Linux 8 and inherits all of its hardware certifications and requirements. See Red Hat Enterprise Linux technology capabilities and limits.

1.1.3.2. Network connectivity requirements

All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require network in initramfs during boot to fetch Ignition config files from the Machine Config Server. The machines are configured with static IP addresses. No DHCP server is required.

1.1.3.3. IBM Z network connectivity requirements

To install on IBM Z under z/VM, you require a single z/VM virtual NIC in layer 2 mode. You also need:

A direct-attached OSA or RoCE network adapter
A z/VM VSWITCH set up. For a preferred setup, use OSA link aggregation.

1.1.3.4. Minimum resource requirements

Each cluster machine must meet the following minimum requirements:

Machine	Operating System	vCPU¹	Virtual RAM	Storage
Bootstrap	RHCOS	4	16 GB	120 GB
Control plane	RHCOS	4	16 GB	120 GB
Compute	RHCOS	2	8 GB	120 GB
¹ 1 physical core provides 2 vCPUs when hyper-threading is enabled. 1 physical core provides 1 vCPU when hyper-threading is not enabled.

1.1.3.5. Minimum IBM Z system requirements

You can install OpenShift Container Platform version 4.4 on the following IBM hardware:

IBM Z: z13, z13s, all z14 models, all z15 models
LinuxONE: all models

Hardware requirements

1 LPAR with 3 IFLs that supports SMT2
1 OSA or RoCE network adapter

Operating system requirements

One instance of z/VM 7.1

On your z/VM instance, set up:

3 guest virtual machines for OpenShift Container Platform control plane machines
2 guest virtual machines for OpenShift Container Platform compute machines
1 guest virtual machine for the temporary OpenShift Container Platform bootstrap machine

Disk storage for the z/VM guest virtual machines

FICON attached disk storage (DASDs). These can be z/VM minidisks, fullpack minidisks, or dedicated DASDs, all of which must be formatted as CDL, which is the default. To reach the minimum required DASD size for Red Hat Enterprise Linux CoreOS (RHCOS) installations, you need extended address volumes (EAV). If available, use HyperPAV to ensure optimal performance.
FCP attached disk storage

Storage / Main Memory

16 GB for OpenShift Container Platform control plane machines
8 GB for OpenShift Container Platform compute machines
16 GB for the temporary OpenShift Container Platform bootstrap machine

1.1.3.6. Preferred IBM Z system requirements

Hardware requirements

3 LPARs with 6 IFLs each that support SMT2
1 or 2 OSA or RoCE network adapters, or both
Hipersockets, which are attached to a node either directly as a device or by bridging with one z/VM VSWITCH to be transparent to the z/VM guest. To directly connect Hipersockets to a node, you must set up a gateway to the external network via a RHEL 8 guest to bridge to the Hipersockets network.

Operating system requirements

2 or 3 instances of z/VM 7.1 for high availability

On your z/VM instances, set up:

3 guest virtual machines for OpenShift Container Platform control plane machines, one per z/VM instance
At least 6 guest virtual machines for OpenShift Container Platform compute machines, distributed across the z/VM instances
1 guest virtual machine for the temporary OpenShift Container Platform bootstrap machine

Disk storage for the z/VM guest virtual machines

FICON attached disk storage (DASDs). These can be z/VM minidisks, fullpack minidisks, or dedicated DASDs, all of which must be formatted as CDL, which is the default. To reach the minimum required DASD size for Red Hat Enterprise Linux CoreOS (RHCOS) installations, you need extended address volumes (EAV). If available, use HyperPAV and High Performance FICON (zHPF) to ensure optimal performance.
FCP attached disk storage

Storage / Main Memory

16 GB for OpenShift Container Platform control plane machines
8 GB for OpenShift Container Platform compute machines
16 GB for the temporary OpenShift Container Platform bootstrap machine

1.1.3.7. 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

See Bridging a HiperSockets LAN with a z/VM Virtual Switch in the IBM Knowledge Center.
See Scaling HyperPAV alias devices on Linux guests on z/VM for performance optimization.

1.1.4. 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

Set up static IP addresses.
Set up an FTP server.
Provision the required load balancers.
Configure the ports for your machines.
Configure DNS.
Ensure network connectivity.

1.1.4.1. 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 an FTP server in order to establish a network connection to download their Ignition config files.

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

The Kubernetes API server, which runs on each master node after a successful cluster installation, 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.

Table 1.1. All machines to all machines
Protocol	Port	Description
ICMP	N/A	Network reachability tests
TCP	`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 1.2. All machines to control plane
Protocol	Port	Description
TCP	`2379`-`2380`	etcd server, peer, and metrics ports
TCP	`6443`	Kubernetes API

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.

Note

Session persistence is not required for the API load balancer to function properly.

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

Table 1.3. 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 1.4. 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.

1.1.4.2. 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 1.5. 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>.`	Add DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for 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 1.1. 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 1.2. 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.ocp4.example.com.
5	IN	PTR	api-int.ocp4.ocp4.example.com.
;
11	IN	PTR	worker0.ocp4.example.com.
7	IN	PTR	worker1.ocp4.example.com.
;
;EOF

1.1.5. 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 SSH key. Do not specify an existing SSH key, as it will be overwritten.
Running this command generates an SSH key that does not require a password in the location that you specified.
Start the ssh-agent process as a background task:
```
$ eval "$(ssh-agent -s)"

Agent pid 31874
```
Add your SSH private key to the ssh-agent:
```
$ ssh-add <path>/<file_name> 1

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.

1.1.6. Obtaining the installation program

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

Prerequisites

You must install the cluster from a machine that runs Linux, for example Red Hat Enterprise Linux 8.
You need 500 MB of local disk space to download the installation program.

Procedure

Access the Infrastructure Provider page on the Red Hat OpenShift Cluster Manager site. If you have a Red Hat account, log in with your credentials. If you do not, create an account.
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 both the installation program and the files that the installation program creates after you finish installing the cluster.
Important
Deleting the files created by the installation program does not remove your cluster, even if the cluster failed during installation. You must complete the OpenShift Container Platform uninstallation procedures outlined for your specific cloud provider to remove your cluster entirely.
Extract the installation program. For example, on a computer that uses a Linux operating system, run the following command:
```
$ tar xvf <installation_program>.tar.gz
```
From the Pull Secret page on the Red Hat OpenShift Cluster Manager site, download your installation pull secret as a .txt file. 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.

1.1.7. Installing the CLI by downloading the binary

You can install the OpenShift CLI (oc) in order 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 4.4. Download and install the new version of oc.

1.1.7.1. Installing the CLI on Linux

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

Procedure

Navigate to the Infrastructure Provider page on the Red Hat OpenShift Cluster Manager site.
Select your infrastructure provider, and, if applicable, your installation type.
In the Command-line interface section, select Linux from the drop-down menu and click Download command-line tools.
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 CLI, it is available using the oc command:

$ oc <command>

1.1.7.2. Installing the CLI on Windows

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

Procedure

Navigate to the Infrastructure Provider page on the Red Hat OpenShift Cluster Manager site.
Select your infrastructure provider, and, if applicable, your installation type.
In the Command-line interface section, select Windows from the drop-down menu and click Download command-line tools.
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 CLI, it is available using the oc command:

C:\> oc <command>

1.1.7.3. Installing the CLI on macOS

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

Procedure

Navigate to the Infrastructure Provider page on the Red Hat OpenShift Cluster Manager site.
Select your infrastructure provider, and, if applicable, your installation type.
In the Command-line interface section, select MacOS from the drop-down menu and click Download command-line tools.
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 CLI, it is available using the oc command:

$ oc <command>

1.1.8. Manually creating the installation configuration file

For installations of OpenShift Container Platform that use user-provisioned infrastructure, you must 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.

1.1.8.1. 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:
- hyperthreading: Enabled 2 3
  name: worker
  replicas: 0 4
controlPlane:
  hyperthreading: Enabled 5 6
  name: master 7
  replicas: 3 8
metadata:
  name: test 9
networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14 10
    hostPrefix: 23 11
  networkType: OpenShiftSDN
  serviceNetwork: 12
  - 172.30.0.0/16
platform:
  none: {} 13
fips: false 14
pullSecret: '{"auths": ...}' 15
sshKey: 'ssh-ed25519 AAAA...' 16

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. Although both sections currently define a single machine pool, it is possible that future versions of OpenShift Container Platform will support defining multiple compute pools during installation. Only one control plane pool is used.
3 6 7: Whether to enable or disable simultaneous multithreading, or hyperthreading. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores. You can disable it by setting the parameter value to Disabled. If you disable simultaneous multithreading in some cluster machines, you must disable it in all cluster machines.
Important
If you disable simultaneous multithreading, 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.
8: The number of control plane machines that you add to the cluster. Because the cluster uses this values as the number of etcd endpoints in the cluster, the value must match the number of control plane machines that you deploy.
9: The cluster name that you specified in your DNS records.
10: 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.
11: 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.
12: The IP address pool to use for service IP addresses. You can enter only one IP address pool. If you need to access the services from an external network, configure load balancers and routers to manage the traffic.
13: You must set the platform to none. You cannot provide additional platform configuration variables for IBM Z infrastructure.
14: 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.
15: The pullSecret value contains the authentication information for your registry. For <bastion_host_name>, specify the registry domain name that you specified in the certificate for your mirror registry, and for <credentials>, specify the base64-encoded user name and password for your mirror registry. 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.
16: 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.

1.1.9. 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.

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.

Prerequisites

Obtain the OpenShift Container Platform installation program.
Create the install-config.yaml installation configuration file.

Procedure

Generate the Kubernetes manifests for the cluster:
```
$ ./openshift-install create manifests --dir=<installation_directory> 1

INFO Consuming Install Config from target directory
WARNING Making control-plane schedulable by setting MastersSchedulable to true for Scheduler cluster settings
```
1
For <installation_directory>, specify the installation directory that contains the install-config.yaml file you created.
Because you create your own compute machines later in the installation process, you can safely ignore this warning.
Modify the <installation_directory>/manifests/cluster-scheduler-02-config.yml Kubernetes manifest file to prevent 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 set its value to False.
3. Save and exit the file.
Note
Currently, due to a Kubernetes limitation, router Pods running on control plane machines will not be reachable by the ingress load balancer. This step might not be required in a future minor version of OpenShift Container Platform.

Obtain the Ignition config files:

$ ./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

1.1.10. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines

Before you install a cluster on IBM Z infrastructure that you provision, you must install RHCOS on z/VM guest virtual machines for the cluster to use. Complete the following steps to create the machines.

Prerequisites

An FTP server running on your provisioning machine that is accessible to the machines you create.

Procedure

Log in to Linux on your provisioning machine.
Download the Red Hat Enterprise Linux CoreOS (RHCOS) installation files from the RHCOS image mirror.
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. Use the image versions that match your OpenShift Container Platform version if they are available.
Download the following files:
- The initramfs: rhcos-<version>-installer-initramfs.img
- The kernel: rhcos-<version>-installer-kernel
- The operating system image for the disk on which you want to install RHCOS. This type can differ by virtual machine:
  rhcos-<version>-s390x-dasd.s390x.raw.gz for DASD
  rhcos-<version>-s390x-metal.s390x.raw.gz for FCP
Create parameter files. The following parameters are specific for a particular virtual machine:
- For coreos.inst.install_dev=, specify dasda for a DASD installation, or sda for FCP. Note that FCP requires zfcp.allow_lun_scan=0.
- For rd.dasd=, specifys the DASD where RHCOS is to be installed.
- rd.zfcp=<adapter>,<wwpn>,<lun> specifies the FCP disk to install RHCOS on.
- For ip=, specify the following seven entries:
  1. The IP address for the machine.
  2. An empty string.
  3. The gateway.
  4. The netmask.
  5. The machine host and domain name in the form hostname.domainname. Omit this value to let RHCOS decide set it.
  6. The network interface name. Omit this value to let RHCOS decide set it.
  7. If you use static IP addresses, an empty string.
- For coreos.inst.ignition_url=, specify the Ignition file for the machine role. Use bootstrap.ign, master.ign, or worker.ign.
- All other parameters can stay as they are.
  Example parameter file, bootstrap-0.parm, for the bootstrap machine:
```
rd.neednet=1 coreos.inst=yes coreos.inst.install_dev=dasda coreos.inst.image_url=ftp://
cl1.provide.example.com:8080/assets/rhcos-43.80.20200430.0-s390x-dasd.390x.raw.gz
coreos.inst.ignition_url=ftp://cl1.provide.example.com:8080/ignition-bootstrap-0
ip=172.18.78.2::172.18.78.1:255.255.255.0:::none nameserver=172.18.78.1
rd.znet=qeth,0.0.bdf0,0.0.bdf1,0.0.bdf2,layer2=1,portno=0 zfcp.allow_lun_scan=0 cio_ignore=all,
!condev rd.dasd=0.0.3490
```
Transfer the initramfs, kernel, parameter files, and RHCOS images to z/VM, for example with FTP. For details about how to transfer the files with FTP and boot from the virtual reader, see Installing under Z/VM.
Punch the files to the virtual reader of the z/VM guest virtual machine that is to become your bootstrap node.
See PUNCH in the IBM Knowledge Center.
Tip
You can use the CP PUNCH command or, if you use Linux, the vmur command to transfer files between two z/VM guest virtual machines.
Log in to CMS on the bootstrap machine.
IPL the bootstrap machine from the reader:
```
$ ipl c
```
See IPL in the IBM Knowledge Center.
Repeat this procedure for the other machines in the cluster.

1.1.11. 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
INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com...
INFO API v1.17.1 up
INFO Waiting up to 30m0s for bootstrapping to complete...
INFO It is now safe to remove the bootstrap resources
```
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.
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.

1.1.12. Logging in to the cluster

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

Deploy an OpenShift Container Platform cluster.
Install 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
system:admin
```

1.1.13. 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

NAME                    STATUS   ROLES    AGE   VERSION
master-01.example.com   Ready    master   40d   v1.17.1
master-02.example.com   Ready    master   40d   v1.17.1
master-03.example.com   Ready    master   40d   v1.17.1
worker-01.example.com   Ready    worker   40d   v1.17.1
worker-02.example.com   Ready    worker   40d   v1.17.1

The output lists all of the machines that you created.

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

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. After you approve the initial CSRs, the subsequent node client CSRs are automatically approved by the cluster kube-controller-manager. You must implement a method of automatically approving the kubelet serving certificate requests.
- 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
```

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.

1.1.14. 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

NAME                                 VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                       4.4.0     True        False         False      69s
cloud-credential                     4.4.0     True        False         False      12m
cluster-autoscaler                   4.4.0     True        False         False      11m
console                              4.4.0     True        False         False      46s
dns                                  4.4.0     True        False         False      11m
image-registry                       4.4.0     True        False         False      5m26s
ingress                              4.4.0     True        False         False      5m36s
kube-apiserver                       4.4.0     True        False         False      8m53s
kube-controller-manager              4.4.0     True        False         False      7m24s
kube-scheduler                       4.4.0     True        False         False      12m
machine-api                          4.4.0     True        False         False      12m
machine-config                       4.4.0     True        False         False      7m36s
marketplace                          4.4.0     True        False         False      7m54m
monitoring                           4.4.0     True        False         False      7h54s
network                              4.4.0     True        False         False      5m9s
node-tuning                          4.4.0     True        False         False      11m
openshift-apiserver                  4.4.0     True        False         False      11m
openshift-controller-manager         4.4.0     True        False         False      5m943s
openshift-samples                    4.4.0     True        False         False      3m55s
operator-lifecycle-manager           4.4.0     True        False         False      11m
operator-lifecycle-manager-catalog   4.4.0     True        False         False      11m
service-ca                           4.4.0     True        False         False      11m
service-catalog-apiserver            4.4.0     True        False         False      5m26s
service-catalog-controller-manager   4.4.0     True        False         False      5m25s
storage                              4.4.0     True        False         False      5m30s

Configure the Operators that are not available.

1.1.14.1. 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 the Registry Operator is made available.

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

1.1.14.1.1. Configuring registry storage for bare metal

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

Prerequisites

Cluster administrator permissions.
A cluster on bare metal.
Persistent storage provisioned for your cluster, such as Red Hat OpenShift Container Storage.
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
```
Note
If the storage type is emptyDIR, the replica number cannot be greater than 1.
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
```

1.1.14.1.2. 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.

1.1.15. 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:

$ watch -n5 oc get clusteroperators

NAME                                       VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.4.3     True        False         False      7m56s
cloud-credential                           4.4.3     True        False         False      31m
cluster-autoscaler                         4.4.3     True        False         False      16m
console                                    4.4.3     True        False         False      10m
csi-snapshot-controller                    4.4.3     True        False         False      16m
dns                                        4.4.3     True        False         False      22m
etcd                                       4.4.3     False       False         False      25s
image-registry                             4.4.3     True        False         False      16m
ingress                                    4.4.3     True        False         False      16m
insights                                   4.4.3     True        False         False      17m
kube-apiserver                             4.4.3     True        False         False      19m
kube-controller-manager                    4.4.3     True        False         False      20m
kube-scheduler                             4.4.3     True        False         False      20m
kube-storage-version-migrator              4.4.3     True        False         False      16m
machine-api                                4.4.3     True        False         False      22m
machine-config                             4.4.3     True        False         False      22m
marketplace                                4.4.3     True        False         False      16m
monitoring                                 4.4.3     True        False         False      10m
network                                    4.4.3     True        False         False      23m
node-tuning                                4.4.3     True        False         False      23m
openshift-apiserver                        4.4.3     True        False         False      17m
openshift-controller-manager               4.4.3     True        False         False      15m
openshift-samples                          4.4.3     True        False         False      16m
operator-lifecycle-manager                 4.4.3     True        False         False      22m
operator-lifecycle-manager-catalog         4.4.3     True        False         False      22m
operator-lifecycle-manager-packageserver   4.4.3     True        False         False      18m
service-ca                                 4.4.3     True        False         False      23m
service-catalog-apiserver                  4.4.3     True        False         False      23m
service-catalog-controller-manager         4.4.3     True        False         False      23m
storage                                    4.4.3     True        False         False      17m

When all of the cluster Operators are AVAILABLE, you can complete the installation.

Monitor for cluster completion:
```
$ ./openshift-install --dir=<installation_directory> wait-for install-complete 1
INFO Waiting up to 30m0s for the cluster to initialize...
```
1
For <installation_directory>, specify the path to the directory that you stored the installation files in.
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.

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

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.

1.1.16. 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
```
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.

1.1.17. Next steps

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

1.2. Installing a cluster on IBM Z and LinuxONE in a restricted network

In OpenShift Container Platform version 4.4, you can install a cluster on IBM Z and LinuxONE infrastructure that you provision in a restricted network.

Note

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

Important

1.2.1. Prerequisites

Create a mirror registry on your bastion host and obtain the imageContentSources data for your version of OpenShift Container Platform.
Before you begin the disconnected installation process, you must move or remove the existing /usr/local/bin/openshift-install bastion file. This ensures that the updated /usr/local/bin/openshift-install file is created during the disconnected installation process.
Important
Because the installation media is on the bastion host, use that computer to complete all installation steps.
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 and plan to use telemetry, you must configure the firewall to allow the sites that your cluster requires access to.
Note
Be sure to also review this site list if you are configuring a proxy.

1.2.2. About installations in restricted networks

In OpenShift Container Platform 4.4, you can perform an installation that does not require an active connection to the Internet to obtain software components. You complete an installation in a restricted network on only infrastructure that you provision, not infrastructure that the installation program provisions, so your platform selection is limited.

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 IAM service, require Internet access, so you might still 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

Restricted network installations always use user-provisioned infrastructure. 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. Completing this test installation might make it easier to isolate and troubleshoot any issues that might arise during your installation in a restricted network.

1.2.2.1. 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.

1.2.3. 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.

1.2.3.1. Required machines

The smallest OpenShift Container Platform clusters require the following hosts:

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 z/VM instances on at least two physical machines.

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

Note that RHCOS is based on Red Hat Enterprise Linux 8 and inherits all of its hardware certifications and requirements. See Red Hat Enterprise Linux technology capabilities and limits.

1.2.3.2. Network connectivity requirements

1.2.3.3. IBM Z network connectivity requirements

To install on IBM Z under z/VM, you require a single z/VM virtual NIC in layer 2 mode. You also need:

A direct-attached OSA or RoCE network adapter
A z/VM VSWITCH set up. For a preferred setup, use OSA link aggregation.

1.2.3.4. Minimum resource requirements

Each cluster machine must meet the following minimum requirements:

Machine	Operating System	vCPU¹	Virtual RAM	Storage
Bootstrap	RHCOS	4	16 GB	120 GB
Control plane	RHCOS	4	16 GB	120 GB
Compute	RHCOS	2	8 GB	120 GB
¹ 1 physical core provides 2 vCPUs when hyper-threading is enabled. 1 physical core provides 1 vCPU when hyper-threading is not enabled.

1.2.3.5. Minimum IBM Z system requirements

You can install OpenShift Container Platform version 4.4 on the following IBM hardware:

IBM Z: z13, z13s, all z14 models, all z15 models
LinuxONE: all models

Hardware requirements

1 LPAR with 3 IFLs that supports SMT2
1 OSA or RoCE network adapter

Operating system requirements

One instance of z/VM 7.1

On your z/VM instance, set up:

3 guest virtual machines for OpenShift Container Platform control plane machines
2 guest virtual machines for OpenShift Container Platform compute machines
1 guest virtual machine for the temporary OpenShift Container Platform bootstrap machine

Disk storage for the z/VM guest virtual machines

FICON attached disk storage (DASDs). These can be z/VM minidisks, fullpack minidisks, or dedicated DASDs, all of which must be formatted as CDL, which is the default. To reach the minimum required DASD size for Red Hat Enterprise Linux CoreOS (RHCOS) installations, you need extended address volumes (EAV). If available, use HyperPAV to ensure optimal performance.
FCP attached disk storage

Storage / Main Memory

16 GB for OpenShift Container Platform control plane machines
8 GB for OpenShift Container Platform compute machines
16 GB for the temporary OpenShift Container Platform bootstrap machine

1.2.3.6. Preferred IBM Z system requirements

Hardware requirements

3 LPARs with 6 IFLs each that support SMT2
1 or 2 OSA or RoCE network adapters, or both
Hipersockets, which are attached to a node either directly as a device or by bridging with one z/VM VSWITCH to be transparent to the z/VM guest. To directly connect Hipersockets to a node, you must set up a gateway to the external network via a RHEL 8 guest to bridge to the Hipersockets network.

Operating system requirements

2 or 3 instances of z/VM 7.1 for high availability

On your z/VM instances, set up:

3 guest virtual machines for OpenShift Container Platform control plane machines, one per z/VM instance
At least 6 guest virtual machines for OpenShift Container Platform compute machines, distributed across the z/VM instances
1 guest virtual machine for the temporary OpenShift Container Platform bootstrap machine

Disk storage for the z/VM guest virtual machines

FICON attached disk storage (DASDs). These can be z/VM minidisks, fullpack minidisks, or dedicated DASDs, all of which must be formatted as CDL, which is the default. To reach the minimum required DASD size for Red Hat Enterprise Linux CoreOS (RHCOS) installations, you need extended address volumes (EAV). If available, use HyperPAV and High Performance FICON (zHPF) to ensure optimal performance.
FCP attached disk storage

Storage / Main Memory

16 GB for OpenShift Container Platform control plane machines
8 GB for OpenShift Container Platform compute machines
16 GB for the temporary OpenShift Container Platform bootstrap machine

1.2.3.7. Certificate signing requests management

Additional resources

See Bridging a HiperSockets LAN with a z/VM Virtual Switch in the IBM Knowledge Center.
See Scaling HyperPAV alias devices on Linux guests on z/VM for performance optimization.

1.2.4. 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.
Provision the required load balancers.
Configure the ports for your machines.
Configure DNS.
Ensure network connectivity.

1.2.4.1. 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 in order 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.

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 1.6. All machines to all machines
Protocol	Port	Description
ICMP	N/A	Network reachability tests
TCP	`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 1.7. All machines to control plane
Protocol	Port	Description
TCP	`2379`-`2380`	etcd server, peer, and metrics ports
TCP	`6443`	Kubernetes API

Network topology requirements

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

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.

Note

Session persistence is not required for the API load balancer to function properly.

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

Table 1.8. 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 1.9. 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.

1.2.4.2. User-provisioned DNS requirements

Table 1.10. 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>.`	Add DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for 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 1.3. 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 1.4. 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.ocp4.example.com.
5	IN	PTR	api-int.ocp4.ocp4.example.com.
;
11	IN	PTR	worker0.ocp4.example.com.
7	IN	PTR	worker1.ocp4.example.com.
;
;EOF

1.2.5. 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 SSH key. Do not specify an existing SSH key, as it will be overwritten.
Running this command generates an SSH key that does not require a password in the location that you specified.
Start the ssh-agent process as a background task:
```
$ eval "$(ssh-agent -s)"

Agent pid 31874
```
Add your SSH private key to the ssh-agent:
```
$ ssh-add <path>/<file_name> 1

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.

1.2.6. Manually creating the installation configuration file

For installations of OpenShift Container Platform that use user-provisioned infrastructure, you must 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.

1.2.6.1. 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:
- hyperthreading: Enabled 2 3
  name: worker
  replicas: 0 4
controlPlane:
  hyperthreading: Enabled 5 6
  name: master 7
  replicas: 3 8
metadata:
  name: test 9
networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14 10
    hostPrefix: 23 11
  networkType: OpenShiftSDN
  serviceNetwork: 12
  - 172.30.0.0/16
platform:
  none: {} 13
fips: false 14
pullSecret: '{"auths":{"<local_registry>": {"auth": "<credentials>","email": "you@example.com"}}}' 15
sshKey: 'ssh-ed25519 AAAA...' 16
additionalTrustBundle: | 17
  -----BEGIN CERTIFICATE-----
  ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
  -----END CERTIFICATE-----
imageContentSources: 18
- 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: 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. Although both sections currently define a single machine pool, it is possible that future versions of OpenShift Container Platform will support defining multiple compute pools during installation. Only one control plane pool is used.
3 6 7: Whether to enable or disable simultaneous multithreading, or hyperthreading. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores. You can disable it by setting the parameter value to Disabled. If you disable simultaneous multithreading in some cluster machines, you must disable it in all cluster machines.
Important
If you disable simultaneous multithreading, 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.
8: The number of control plane machines that you add to the cluster. Because the cluster uses this values as the number of etcd endpoints in the cluster, the value must match the number of control plane machines that you deploy.
9: The cluster name that you specified in your DNS records.
10: 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.
11: 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.
12: The IP address pool to use for service IP addresses. You can enter only one IP address pool. If you need to access the services from an external network, configure load balancers and routers to manage the traffic.
13: You must set the platform to none. You cannot provide additional platform configuration variables for IBM Z infrastructure.
14: 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.
15: 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.
16: 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.
17: 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 exiting, trusted certificate authority or the self-signed certificate that you generated for the mirror registry.
18: Provide the imageContentSources section from the output of the command to mirror the repository.

1.2.6.2. 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

An existing install-config.yaml file.
Review the sites that your cluster requires access to and determine whether any need to bypass the proxy. By default, all cluster egress traffic is proxied, including calls to hosting cloud provider APIs. Add 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: http://<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. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must not specify an httpProxy value.
2
A proxy URL to use for creating HTTPS connections outside the cluster. If this field is not specified, then httpProxy is used for both HTTP and HTTPS connections. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must not specify an httpsProxy value.
3
A comma-separated list of destination domain names, domains, IP addresses, or other network CIDRs to exclude proxying. Preface a domain with . to include all subdomains of that domain. Use * to bypass 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 that contains one or more additional CA certificates that are required for proxying HTTPS connections. The Cluster Network Operator then creates a trusted-ca-bundle config map that merges these contents with the Red Hat Enterprise Linux CoreOS (RHCOS) trust bundle, and this config map is referenced in the Proxy object’s trustedCA field. The additionalTrustBundle field is required unless the proxy’s identity certificate is signed by an authority from the RHCOS trust bundle. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must provide the MITM CA certificate.
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.

1.2.7. Creating the Kubernetes manifest and Ignition config files

Important

Prerequisites

Obtain the OpenShift Container Platform installation program.
Create the install-config.yaml installation configuration file.

Procedure

Generate the Kubernetes manifests for the cluster:
```
$ ./openshift-install create manifests --dir=<installation_directory> 1

INFO Consuming Install Config from target directory
WARNING Making control-plane schedulable by setting MastersSchedulable to true for Scheduler cluster settings
```
1
For <installation_directory>, specify the installation directory that contains the install-config.yaml file you created.
Because you create your own compute machines later in the installation process, you can safely ignore this warning.
Modify the <installation_directory>/manifests/cluster-scheduler-02-config.yml Kubernetes manifest file to prevent 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 set its value to False.
3. Save and exit the file.
Note
Currently, due to a Kubernetes limitation, router Pods running on control plane machines will not be reachable by the ingress load balancer. This step might not be required in a future minor version of OpenShift Container Platform.

Obtain the Ignition config files:

$ ./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

1.2.8. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines

Prerequisites

An FTP server running on your provisioning machine that is accessible to the machines you create.

Procedure

Log in to Linux on your provisioning machine.
Download the Red Hat Enterprise Linux CoreOS (RHCOS) installation files from the RHCOS image mirror.
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. Use the image versions that match your OpenShift Container Platform version if they are available.
Download the following files:
- The initramfs: rhcos-<version>-installer-initramfs.img
- The kernel: rhcos-<version>-installer-kernel
- The operating system image for the disk on which you want to install RHCOS. This type can differ by virtual machine:
  rhcos-<version>-s390x-dasd.s390x.raw.gz for DASD
  rhcos-<version>-s390x-metal.s390x.raw.gz for FCP
Create parameter files. The following parameters are specific for a particular virtual machine:
- For coreos.inst.install_dev=, specify dasda for a DASD installation, or sda for FCP. Note that FCP requires zfcp.allow_lun_scan=0.
- For rd.dasd=, specifys the DASD where RHCOS is to be installed.
- rd.zfcp=<adapter>,<wwpn>,<lun> specifies the FCP disk to install RHCOS on.
- For ip=, specify the following seven entries:
  1. The IP address for the machine.
  2. An empty string.
  3. The gateway.
  4. The netmask.
  5. The machine host and domain name in the form hostname.domainname. Omit this value to let RHCOS decide set it.
  6. The network interface name. Omit this value to let RHCOS decide set it.
  7. If you use static IP addresses, an empty string.
- For coreos.inst.ignition_url=, specify the Ignition file for the machine role. Use bootstrap.ign, master.ign, or worker.ign.
- All other parameters can stay as they are.
  Example parameter file, bootstrap-0.parm, for the bootstrap machine:
```
rd.neednet=1 coreos.inst=yes coreos.inst.install_dev=dasda coreos.inst.image_url=ftp://
cl1.provide.example.com:8080/assets/rhcos-43.80.20200430.0-s390x-dasd.390x.raw.gz
coreos.inst.ignition_url=ftp://cl1.provide.example.com:8080/ignition-bootstrap-0
ip=172.18.78.2::172.18.78.1:255.255.255.0:::none nameserver=172.18.78.1
rd.znet=qeth,0.0.bdf0,0.0.bdf1,0.0.bdf2,layer2=1,portno=0 zfcp.allow_lun_scan=0 cio_ignore=all,
!condev rd.dasd=0.0.3490
```
Transfer the initramfs, kernel, parameter files, and RHCOS images to z/VM, for example with FTP. For details about how to transfer the files with FTP and boot from the virtual reader, see Installing under Z/VM.
Punch the files to the virtual reader of the z/VM guest virtual machine that is to become your bootstrap node.
See PUNCH in the IBM Knowledge Center.
Tip
You can use the CP PUNCH command or, if you use Linux, the vmur command to transfer files between two z/VM guest virtual machines.
Log in to CMS on the bootstrap machine.
IPL the bootstrap machine from the reader:
```
$ ipl c
```
See IPL in the IBM Knowledge Center.
Repeat this procedure for the other machines in the cluster.

1.2.9. 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.

Procedure

Monitor the bootstrap process:
```
$ ./openshift-install --dir=<installation_directory> wait-for bootstrap-complete \ 1
    --log-level=info 2
INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com...
INFO API v1.17.1 up
INFO Waiting up to 30m0s for bootstrapping to complete...
INFO It is now safe to remove the bootstrap resources
```
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.
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.

1.2.10. Logging in to the cluster

Prerequisites

Deploy an OpenShift Container Platform cluster.
Install 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
system:admin
```

1.2.11. 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

NAME                    STATUS   ROLES    AGE   VERSION
master-01.example.com   Ready    master   40d   v1.17.1
master-02.example.com   Ready    master   40d   v1.17.1
master-03.example.com   Ready    master   40d   v1.17.1
worker-01.example.com   Ready    worker   40d   v1.17.1
worker-02.example.com   Ready    worker   40d   v1.17.1

The output lists all of the machines that you created.

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

NAME        AGE     REQUESTOR                                                                   CONDITION
csr-8b2br   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
csr-8vnps   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
...

In this example, two machines are joining the cluster. You might see more approved CSRs in the list.

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. After you approve the initial CSRs, the subsequent node client CSRs are automatically approved by the cluster kube-controller-manager. You must implement a method of automatically approving the kubelet serving certificate requests.
- 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
```

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.

1.2.12. 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

NAME                                 VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                       4.4.0     True        False         False      69s
cloud-credential                     4.4.0     True        False         False      12m
cluster-autoscaler                   4.4.0     True        False         False      11m
console                              4.4.0     True        False         False      46s
dns                                  4.4.0     True        False         False      11m
image-registry                       4.4.0     True        False         False      5m26s
ingress                              4.4.0     True        False         False      5m36s
kube-apiserver                       4.4.0     True        False         False      8m53s
kube-controller-manager              4.4.0     True        False         False      7m24s
kube-scheduler                       4.4.0     True        False         False      12m
machine-api                          4.4.0     True        False         False      12m
machine-config                       4.4.0     True        False         False      7m36s
marketplace                          4.4.0     True        False         False      7m54m
monitoring                           4.4.0     True        False         False      7h54s
network                              4.4.0     True        False         False      5m9s
node-tuning                          4.4.0     True        False         False      11m
openshift-apiserver                  4.4.0     True        False         False      11m
openshift-controller-manager         4.4.0     True        False         False      5m943s
openshift-samples                    4.4.0     True        False         False      3m55s
operator-lifecycle-manager           4.4.0     True        False         False      11m
operator-lifecycle-manager-catalog   4.4.0     True        False         False      11m
service-ca                           4.4.0     True        False         False      11m
service-catalog-apiserver            4.4.0     True        False         False      5m26s
service-catalog-controller-manager   4.4.0     True        False         False      5m25s
storage                              4.4.0     True        False         False      5m30s

Configure the Operators that are not available.

1.2.12.1. Image registry storage configuration

1.2.12.1.1. Configuring registry storage for bare metal

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

Prerequisites

Cluster administrator permissions.
A cluster on bare metal.
Persistent storage provisioned for your cluster, such as Red Hat OpenShift Container Storage.
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
```
Note
If the storage type is emptyDIR, the replica number cannot be greater than 1.
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
```

1.2.12.1.2. 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.

1.2.13. 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:

$ watch -n5 oc get clusteroperators

NAME                                       VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.4.3     True        False         False      7m56s
cloud-credential                           4.4.3     True        False         False      31m
cluster-autoscaler                         4.4.3     True        False         False      16m
console                                    4.4.3     True        False         False      10m
csi-snapshot-controller                    4.4.3     True        False         False      16m
dns                                        4.4.3     True        False         False      22m
etcd                                       4.4.3     False       False         False      25s
image-registry                             4.4.3     True        False         False      16m
ingress                                    4.4.3     True        False         False      16m
insights                                   4.4.3     True        False         False      17m
kube-apiserver                             4.4.3     True        False         False      19m
kube-controller-manager                    4.4.3     True        False         False      20m
kube-scheduler                             4.4.3     True        False         False      20m
kube-storage-version-migrator              4.4.3     True        False         False      16m
machine-api                                4.4.3     True        False         False      22m
machine-config                             4.4.3     True        False         False      22m
marketplace                                4.4.3     True        False         False      16m
monitoring                                 4.4.3     True        False         False      10m
network                                    4.4.3     True        False         False      23m
node-tuning                                4.4.3     True        False         False      23m
openshift-apiserver                        4.4.3     True        False         False      17m
openshift-controller-manager               4.4.3     True        False         False      15m
openshift-samples                          4.4.3     True        False         False      16m
operator-lifecycle-manager                 4.4.3     True        False         False      22m
operator-lifecycle-manager-catalog         4.4.3     True        False         False      22m
operator-lifecycle-manager-packageserver   4.4.3     True        False         False      18m
service-ca                                 4.4.3     True        False         False      23m
service-catalog-apiserver                  4.4.3     True        False         False      23m
service-catalog-controller-manager         4.4.3     True        False         False      23m
storage                                    4.4.3     True        False         False      17m

When all of the cluster Operators are AVAILABLE, you can complete the installation.

Monitor for cluster completion:
```
$ ./openshift-install --dir=<installation_directory> wait-for install-complete 1
INFO Waiting up to 30m0s for the cluster to initialize...
```
1
For <installation_directory>, specify the path to the directory that you stored the installation files in.
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.

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

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.

1.2.14. 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
```
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 OpenShift Container Platform version 4 nodes without SSH.

1.2.15. Next steps

Customize your cluster.

Legal Notice

OpenShift documentation is licensed under the Apache License 2.0 (https://www.apache.org/licenses/LICENSE-2.0).

Modified versions must remove all Red Hat trademarks.

Portions adapted from https://github.com/kubernetes-incubator/service-catalog/ with modifications by Red Hat.

Red Hat, Red Hat Enterprise Linux, the Red Hat logo, the Shadowman logo, JBoss, OpenShift, Fedora, the Infinity logo, and RHCE are trademarks of Red Hat, Inc., registered in the United States and other countries.

Linux® is the registered trademark of Linus Torvalds in the United States and other countries.

Java® is a registered trademark of Oracle and/or its affiliates.

XFS® is a trademark of Silicon Graphics International Corp. or its subsidiaries in the United States and/or other countries.

MySQL® is a registered trademark of MySQL AB in the United States, the European Union and other countries.

Node.js® is an official trademark of Joyent. Red Hat Software Collections is not formally related to or endorsed by the official Joyent Node.js open source or commercial project.

The OpenStack® Word Mark and OpenStack logo are either registered trademarks/service marks or trademarks/service marks of the OpenStack Foundation, in the United States and other countries and are used with the OpenStack Foundation’s permission. We are not affiliated with, endorsed or sponsored by the OpenStack Foundation, or the OpenStack community.

All other trademarks are the property of their respective owners.

Installing on IBM Z and LinuxONE

Installing OpenShift Container Platform IBM Z clusters

Chapter 1. Installing on IBM Z

1.1. Installing a cluster on IBM Z and LinuxONE

1.1.1. Prerequisites

1.1.2. Internet and Telemetry access for OpenShift Container Platform

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

1.1.3.1. Required machines

1.1.3.2. Network connectivity requirements

1.1.3.3. IBM Z network connectivity requirements

1.1.3.4. Minimum resource requirements

1.1.3.5. Minimum IBM Z system requirements

Hardware requirements

Operating system requirements

Disk storage for the z/VM guest virtual machines

Storage / Main Memory

1.1.3.6. Preferred IBM Z system requirements

Hardware requirements

Operating system requirements

Disk storage for the z/VM guest virtual machines

Storage / Main Memory

1.1.3.7. Certificate signing requests management

1.1.4. Creating the user-provisioned infrastructure

1.1.4.1. Networking requirements for user-provisioned infrastructure

Network topology requirements

Load balancers

1.1.4.2. User-provisioned DNS requirements

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

1.1.6. Obtaining the installation program

1.1.7. Installing the CLI by downloading the binary

1.1.7.1. Installing the CLI on Linux

1.1.7.2. Installing the CLI on Windows

1.1.7.3. Installing the CLI on macOS

1.1.8. Manually creating the installation configuration file

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

1.1.9. Creating the Kubernetes manifest and Ignition config files

1.1.10. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines

1.1.11. Creating the cluster

1.1.12. Logging in to the cluster

1.1.13. Approving the certificate signing requests for your machines

1.1.14. Initial Operator configuration

1.1.14.1. Image registry storage configuration

1.1.14.1.1. Configuring registry storage for bare metal

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

1.1.15. Completing installation on user-provisioned infrastructure

1.1.16. Collecting debugging information

1.1.17. Next steps

1.2. Installing a cluster on IBM Z and LinuxONE in a restricted network

1.2.1. Prerequisites

1.2.2. About installations in restricted networks

1.2.2.1. Additional limits

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

1.2.3.1. Required machines

1.2.3.2. Network connectivity requirements

1.2.3.3. IBM Z network connectivity requirements

1.2.3.4. Minimum resource requirements

1.2.3.5. Minimum IBM Z system requirements

Hardware requirements

Operating system requirements

Disk storage for the z/VM guest virtual machines

Storage / Main Memory

1.2.3.6. Preferred IBM Z system requirements

Hardware requirements

Operating system requirements

Disk storage for the z/VM guest virtual machines

Storage / Main Memory

1.2.3.7. Certificate signing requests management

1.2.4. Creating the user-provisioned infrastructure

1.2.4.1. Networking requirements for user-provisioned infrastructure

Network topology requirements

Load balancers

1.2.4.2. User-provisioned DNS requirements

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

1.2.6. Manually creating the installation configuration file

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

1.2.6.2. Configuring the cluster-wide proxy during installation

1.2.7. Creating the Kubernetes manifest and Ignition config files

1.2.8. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines

1.2.9. Creating the cluster

1.2.10. Logging in to the cluster

1.1.8.1. Sample `install-config.yaml` file for IBM Z

1.2.6.1. Sample `install-config.yaml` file for IBM Z