HP Serviceguard Quorum Server Version A.04.00 Release Notes, revised August 2009

If the Quorum Server is not available or reachable, it will not adversely affect any clusters using
it, unless a cluster needs to reform and requires the Quorum Server’s arbitration to do so.
As of Serviceguard A.11.19, you can change from one quorum server to another, or to or from
another quorum method, while the cluster is running.
IMPORTANT: For more information, see “What Happens when You Change the Quorum
Configuration Online” in Chapter 3 of Managing Serviceguard.
System Requirements and Recommendations
System Requirements
Operating System and Hardware Requirements
The HP-UX version of Quorum Server version A.04.00 runs on HP 9000 servers, HP Integrity
servers, and HP-UX workstations, running HP-UX 11i v2 or 11i v3.
The Linux version runs on:
• Any hardware specified in the HP Serviceguard for Linux Certification Matrix (which you can
find at: http://www.hp.com/info/sglx) and running one of the following Linux
distributions in IA32, IA64, or x86_64 versions:
— Red Hat 5
— SUSE SLES10
— SUSE SLES11
• Any HP PC supported to run any of the operating systems indicated by the previous bullet.
A Quorum Server can provide quorum services for multiple HP-UX or Linux clusters, or a
combination of both, up 150 clusters but not exceeding 300 nodes in all.
CAUTION: Make sure that each cluster served by a given Quorum Server has a unique cluster
name. Serviceguard normally enforces this, but under some circumstances (for example if the
clusters are on different subnets) Serviceguard will not be able to detect a duplicate name. See
also “Network Recommendations” (page 9).
Memory and Disk Requirements
Memory: 7.0 MB
Disk space: 1 MB
Network Recommendations
• Ideally the Quorum Server and the cluster or clusters it serves should communicate over a
subnet that does not handle other traffic. (If you are using a version of Serviceguard that
supports more than one subnet for communication with the Quorum Server, this should be
true of both subnets.) This helps to ensure that the Quorum Server is available when it is
needed.
If this is not practical, or if the communication must cover a long distance (for example, if
the Quorum Server is serving an Extended Distance cluster) heavy network traffic or network
delays could cause Quorum Server timeouts. You can reduce the likelihood of timeouts by
increasing the Quorum Server timeout interval; use the QS_TIMEOUT_EXTENSION
parameter in the cluster configuration file. See “Configuring Serviceguard to Use the Quorum
System Requirements and Recommendations 9