Planning and Prerequisites Guide

The minimum and recommended hardware requirements outlined here are based on a typical small to medium-sized installation. The exact requirements vary between deployments based on sizing and load.

Hardware certification for Red Hat Virtualization is covered by the hardware certification for Red Hat Enterprise Linux. For more information, see https://access.redhat.com/solutions/725243. To confirm whether specific hardware items are certified for use with Red Hat Enterprise Linux, see https://access.redhat.com/ecosystem/#certifiedHardware.

The following browser versions and operating systems can be used to access the Administration Portal and the VM Portal.

Browser support is divided into tiers:

Virtual machine consoles can only be accessed using supported Remote Viewer (virt-viewer) clients on Red Hat Enterprise Linux and Windows. To install virt-viewer, see Installing Supporting Components on Client Machines in the Virtual Machine Management Guide. Installing virt-viewer requires Administrator privileges.

Virtual machine consoles are accessed through the SPICE, VNC, or RDP (Windows only) protocols. The QXL graphical driver can be installed in the guest operating system for improved/enhanced SPICE functionalities. SPICE currently supports a maximum resolution of 2560x1600 pixels.

Supported QXL drivers are available on Red Hat Enterprise Linux, Windows XP, and Windows 7.

SPICE support is divided into tiers:

The Red Hat Virtualization Manager must be installed on a base installation of Red Hat Enterprise Linux 7 that has been updated to the latest minor release.

Do not install any additional packages after the base installation, as they may cause dependency issues when attempting to install the packages required by the Manager.

Do not enable additional repositories other than those required for the Manager installation.

All CPUs must have support for the Intel® 64 or AMD64 CPU extensions, and the AMD-V™ or Intel VT® hardware virtualization extensions enabled. Support for the No eXecute flag (NX) is also required.

The following CPU models are supported:

The minimum required RAM is 2 GB. The maximum supported RAM per VM in Red Hat Virtualization Host is 4 TB.

However, the amount of RAM required varies depending on guest operating system requirements, guest application requirements, and guest memory activity and usage. KVM can also overcommit physical RAM for virtualized guests, allowing you to provision guests with RAM requirements greater than what is physically present, on the assumption that the guests are not all working concurrently at peak load. KVM does this by only allocating RAM for guests as required and shifting underutilized guests into swap.

Hosts require storage to store configuration, logs, kernel dumps, and for use as swap space. Storage can be local or network-based. Red Hat Virtualization Host (RHVH) can boot with one, some, or all of its default allocations in network storage. Booting from network storage can result in a freeze if there is a network disconnect. Adding a drop-in multipath configuration file can help address losses in network connectivity. If RHVH boots from SAN storage and loses connectivity, the files become read-only until network connectivity restores. Using network storage might result in a performance downgrade.

The minimum storage requirements of RHVH are documented in this section. The storage requirements for Red Hat Enterprise Linux hosts vary based on the amount of disk space used by their existing configuration but are expected to be greater than those of RHVH.

The minimum storage requirements for host installation are listed below. However, Red Hat recommends using the default allocations, which use more storage space.

If you are also installing the RHV-M Appliance for self-hosted engine installation, /var/tmp must be at least 5 GB.

If you plan to use memory overcommitment, add enough swap space to provide virtual memory for all of virtual machines. See Memory Optimization.

Hosts must have at least one network interface with a minimum bandwidth of 1 Gbps. Red Hat recommends that each host have two network interfaces, with one dedicated to supporting network-intensive activities, such as virtual machine migration. The performance of such operations is limited by the bandwidth available.

For information about how to use PCI Express and conventional PCI devices with Intel Q35-based virtual machines, see Using PCI Express and Conventional PCI Devices with the Q35 Virtual Machine.

If you plan to implement device assignment and PCI passthrough so that a virtual machine can use a specific PCIe device from a host, ensure the following requirements are met:

Check vendor specification and datasheets to confirm that your hardware meets these requirements. The lspci -v command can be used to print information for PCI devices already installed on a system.

A host must meet the following requirements in order for virtual machines on that host to use a vGPU:

Red Hat Virtualization requires IPv6 to remain enabled on the computer or virtual machine where you are running the Manager (also called "the Manager machine"). Do not disable IPv6 on the Manager machine, even if your systems do not use it.

The firewall requirements for all of the following topics are special cases that require individual consideration.

By default, Red Hat Enterprise Linux allows outbound traffic to DNS and NTP on any destination address. If you disable outgoing traffic, define exceptions for requests that are sent to DNS and NTP servers.

By default, Red Hat Enterprise Linux allows outbound IPMI traffic to ports on any destination address. If you disable outgoing traffic, make exceptions for requests being sent to your IPMI or fencing servers.

Each Red Hat Virtualization Host and Red Hat Enterprise Linux host in the cluster must be able to connect to the fencing devices of all other hosts in the cluster. If the cluster hosts are experiencing an error (network error, storage error…​) and cannot function as hosts, they must be able to connect to other hosts in the data center.

The specific port number depends on the type of the fence agent you are using and how it is configured.

The firewall requirement tables in the following sections do not represent this option.

The Red Hat Virtualization Manager requires that a number of ports be opened to allow network traffic through the system’s firewall.

The engine-setup script can configure the firewall automatically, but this overwrites any pre-existing firewall configuration if you are using iptables. If you want to keep the existing firewall configuration, you must manually insert the firewall rules required by the Manager. The engine-setup command saves a list of the iptables rules required in the /etc/ovirt-engine/iptables.example file. If you are using firewalld, engine-setup does not overwrite the existing configuration.

The firewall configuration documented here assumes a default configuration.

Red Hat Enterprise Linux hosts and Red Hat Virtualization Hosts (RHVH) require a number of ports to be opened to allow network traffic through the system’s firewall. The firewall rules are automatically configured by default when adding a new host to the Manager, overwriting any pre-existing firewall configuration.

To disable automatic firewall configuration when adding a new host, clear the Automatically configure host firewall check box under Advanced Parameters.

To customize the host firewall rules, see https://access.redhat.com/solutions/2772331.

Red Hat Virtualization supports the use of a remote database server for the Manager database (engine) and the Data Warehouse database (ovirt-engine-history). If you plan to use a remote database server, it must allow connections from the Manager and the Data Warehouse service (which can be separate from the Manager).

Similarly, if you plan to access a local or remote Data Warehouse database from an external system, such as Red Hat CloudForms, the database must allow connections from that system.

Red Hat Virtualization Hosts (RHVH) have the following advantages over Red Hat Enterprise Linux hosts:

Red Hat Enterprise Linux hosts have the following advantages over Red Hat Virtualization Hosts:

NFS versions 3 and 4 are supported by Red Hat Virtualization 4. Production workloads require an enterprise-grade NFS server, unless NFS is only being used as an ISO storage domain. When enterprise NFS is deployed over 10GbE, segregated with VLANs, and individual services are configured to use specific ports, it is both fast and secure.

As NFS exports are grown to accommodate more storage needs, Red Hat Virtualization recognizes the larger data store immediately. No additional configuration is necessary on the hosts or from within Red Hat Virtualization. This provides NFS a slight edge over block storage from a scale and operational perspective.

See:

Production workloads require an enterprise-grade iSCSI server. When enterprise iSCSI is deployed over 10GbE, segregated with VLANs, and utilizes CHAP authentication, it is both fast and secure. iSCSI can also use multipathing to improve high availability.

Red Hat Virtualization supports 1500 logical volumes per block-based storage domain. No more than 300 LUNs are permitted.

See:

Fibre Channel is both fast and secure, and should be taken advantage of if it is already in use in the target data center. It also has the advantage of low CPU overhead as compared to iSCSI and NFS. Fibre Channel can also use multipathing to improve high availability.

Red Hat Virtualization supports 1500 logical volumes per block-based storage domain. No more than 300 LUNs are permitted.

See:

To use Fibre Channel over Ethernet (FCoE) in Red Hat Virtualization, you must enable the fcoe key on the Manager, and install the vdsm-hook-fcoe package on the hosts.

Red Hat Virtualization supports 1500 logical volumes per block-based storage domain. No more than 300 LUNs are permitted.

See:

Red Hat Gluster Storage (RHGS) is a POSIX-compliant and open source file system. Three or more servers are configured as a Red Hat Gluster Storage cluster, instead of network-attached storage (NAS) appliances or a storage area network (SAN) array.

Red Hat Gluster Storage should be utilized over 10GbE and segregated with VLANs.

Check the compatibility matrix in https://access.redhat.com/articles/2356261 before using RHGS with Red Hat Virtualization.

See:

Red Hat Hyperconverged Infrastructure (RHHI) combines Red Hat Virtualization and Red Hat Gluster Storage on the same infrastructure, instead of connecting Red Hat Virtualization to a remote Red Hat Gluster Storage server. This compact option reduces operational expenses and overhead.

See:

Other POSIX-compliant file systems can be used as storage domains in Red Hat Virtualization, as long as they are clustered file systems, such as Red Hat Global File System 2 (GFS2), and support sparse files and direct I/O. The Common Internet File System (CIFS), for example, does not support direct I/O, making it incompatible with Red Hat Virtualization.

See:

Local storage is set up on an individual host, using the host’s own resources. When you set up a host to use local storage, it is automatically added to a new data center and cluster that no other hosts can be added to. Virtual machines created in a single-host cluster cannot be migrated, fenced, or scheduled.

For Red Hat Virtualization Hosts, local storage should always be defined on a file system that is separate from / (root). Red Hat recommends using a separate logical volume or disk.

See: Preparing and Adding Local Storage in the Administration Guide.

The following components can be hosted on either the Manager or a remote machine. Keeping all components on the Manager machine is easier and requires less maintenance, so is preferable when performance is not an issue. Moving components to a remote machine requires more maintenance, but can improve the performance of both the Manager and Data Warehouse.

You can also host the Data Warehouse service and the Data Warehouse database separately from one another.

The following components must be hosted on a remote machine: