Installation guide

RHEL 5 supports two virtualization platforms. Xen has been supported since RHEL 5.0 release. In
RHEL 5.4 KVM was introduced.
RHEL 6 only supports KVM as a virtualization platform.
RHEL 5 AP Cluster supports both KVM and Xen for use in running virtual machines that are managed
by the host cluster infrastructure.
RHEL 6 HA supports KVM for use in running virtual machines that are managed by the host cluster
infrastructure.
The following lists the deployment scenarios currently supported by Red Hat:
RHEL 5.0+ supports Xen in conjunction with RHEL AP Cluster
RHEL 5.4 introduced support for KVM virtual machines as managed resources in RHEL AP Cluster
as a Technology Preview.
RHEL 5.5+ elevates support for KVM virtual machines to be fully supported.
RHEL 6.0+ supports KVM virtual machines as highly available resources in the RHEL 6 High
Availability Add-On.
RHEL 6.0+ does not support Xen virtual machines with the RHEL 6 High Availability Add-On, since
RHEL 6 no longer supports Xen.
Note
For updated information and special notes regarding supported deployment scenarios, refer
to the following Red Hat Knowledgebase entry:
https://access.redhat.com/kb/docs/DOC-46375
The types of virtual machines that are run as managed resources does not matter. Any guest that is
supported by either Xen or KVM in RHEL can be used as a highly available guest. This includes
variants of RHEL (RHEL3, RHEL4, RHEL5) and several variants of Microsoft Windows. Check the
RHEL documentation to find the latest list of supported guest operating systems under each
hypervisor.
7.1.1. General Recommendat ions
In RHEL 5.3 and below, rgmanager utilized the native Xen interfaces for managing Xen domU's
(guests). In RHEL 5.4 this was changed to use libvirt for both the Xen and KVM hypervisors to
provide a consistent interface between both hypervisor types. In addition to this architecture
change there were numerous bug fixes released in RHEL 5.4 and 5.4.z, so it is advisable to
upgrade your host clusters to at least the latest RHEL 5.5 packages before configuring Xen
managed services.
For KVM managed services you must upgrade to RHEL 5.5 as this is the first version of RHEL
where this functionality is fully supported.
Always check the latest RHEL errata before deploying a Cluster to make sure that you have the
latest fixes for known issues or bugs.
Mixing hosts of different hypervisor types is not supported. The host cluster must either be all Xen
or all KVM based.
⁠Chapt er 7 . Virt ualizat ion and High Availabilit y
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