Support Policies for RHEL High Availability Clusters - Microsoft Azure Virtual Machines as Cluster Members

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Applicable Environments

  • Red Hat Enterprise Linux (RHEL) with the High Availability Add-On
  • Using Microsoft Azure to provide instances that may serve as High Availability cluster members

Useful References and Guides


This guide offers Red Hat's policies, requirements, and limitations applicable to the use of Microsoft Azure virtual machines as members of a RHEL High Availability cluster. Users of RHEL High Availability software components should adhere to these policies by installing only on the approved platforms in order to be eligible to receive assistance from Red Hat Support with the appropriate support subscriptions.


Consider general conditions for support of RHEL High Availability in virtualization environments

Supported releases for Microsoft Azure virtual machines as High Availability members: Red Hat supports RHEL High Availability cluster members running on Microsoft Azure virtual machines with the following RHEL releases or later:

  • RHEL 8: Supported by Red Hat
  • RHEL 7:
    • RHEL 7.5 or later: Supported by Red Hat with packages pacemaker-1.1.18-11.el7, corosync-2.4.3-2.el7, fence-agents-*-4.0.11-86.el7 or later.
    • RHEL 7.4: Supported by Red Hat with packages pacemaker-1.1.16-12.el7_4.8, corosync-2.4.0-9.el7_4.2, fence-agents-*-4.0.11-66.el7_4.7 or later.

Supported transport protocols: RHEL 7 High Availability clusters with members that run on the Microsoft Azure platform can only use the udpu transport protocol - which is the default in RHEL 7 clusters. Azure VNETs do not support multicast traffic, preventing the usage of the udp transport protocol.

Red Hat only supports the knet transport in RHEL 8, regardless of platform.

For more information, see:

Known condition with slow fencing in Azure environments: Red Hat is aware of a condition which may cause fencing to take an excessive amount of time to complete in some Azure clusters running RHEL 8.0, 7.6, 7.5, or 7.4. See Red Hat's Knowledge Solution describing this condition for more information, as well as Red Hat's guide to deploying a RHEL 7 High Availability cluster on Azure for instructions on accommodating this condition.