Managing Serviceguard 12th Edition, March 2006

Planning and Documenting an HA Cluster
Quorum Server Planning
Chapter 4 147
Quorum Server Planning
The quorum server (QS) provides tie-breaking services for clusters. The
QS is described in “Use of the Quorum Server as the Cluster Lock” on
page 70.
A quorum server:
• can be used with up to 50 clusters, not exceeding 100 nodes total.
• can support a cluster with any supported number of nodes.
NOTE It is recommended that the node on which the quorum server is running
be in the same subnet as the clusters for which it is providing services.
This will help prevent any network delays which could affect quorum
server operation. If you use a different subnet, you may experience
network delays which may cause quorum server timeouts. To prevent
these timeouts, you can use the QS_TIMEOUT_EXTENSION parameter in
the cluster ASCII file to increase the quorum server timeout interval.
If the network used to connect to the quorum server is a cluster
heartbeat network, ensure that at least one other network is also a
heartbeat network so that both are not likely to fail at the same time.
For more information, see the Quorum Server Release Notes and white
papers at: http://www.docs.hp.com -> High Availability.
Use the Quorum Server Worksheet to identify a quorum server for use
with one or more clusters. You should also enter quorum server host and
timing parameters on the Cluster Configuration Worksheet.
On the QS worksheet, enter the following:
Quorum Server Host
Enter the host name for the quorum server .
IP Address Enter the IP address by which the quorum server will
be accessed. The quorum server has to be configured on
an IPv4 network. IPv6 addresses are not supported.
Supported Node Names