Managing HP Serviceguard for Linux, Seventh Edition, July 2007

Planning and Documenting an HA Cluster
Cluster Lock Planning
Chapter 4102
• Can be used with up to 50 clusters, not exceeding 100 nodes total.
• Can support a cluster with any supported number of nodes.
Networking Recommendations for a Quorum Server
• Ideally the Quorum Server and the cluster or clusters it serves
should communicate over a subnet that does not handle other traffic.
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 “Specifying a Quorum Server” on page 180.
• If a subnet that connects the Quorum Server to a cluster is also used
for the cluster heartbeat, configure the heartbeat on at least one
other network, so that both Quorum Server and heartbeat
communication 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.
Quorum Server Worksheet
Use the Quorum Server Worksheet, in Appendix D, “Blank Planning
Worksheets,” on page 347, to identify a quorum server for use with one or
more clusters. Make as many copies as you need. Fill out the worksheet
and keep it for future reference.
You should also enter quorum server host and timing parameters on the
Cluster Configuration Worksheet; see “Quorum Server Information” on
page 106.
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.