HP Serviceguard Quorum Server for Linux Version A.12.00.00 Release Notes, March 2014

Updating the Quorum Server (SUSE)
An update can be done while the cluster is running.
If you are updating Serviceguard as well, the Quorum Server update must be done before you
update Serviceguard.
1. Comment the Quorum Server entry in /etc/inittab and run the following command:
/sbin/init q
2. Uninstall the existing Quorum Server. For example:
rpm -e qs-A.02.04
CAUTION: This command may remove the file /var/log/qs/qs.log. If this is your log
file, you may want to save it before running this command.
3. Install the version of Quorum Server A.12.00.00 appropriate to your distribution and hardware.
For example:
rpm -ihv serviceguard-qs-A.12.00.00-0.sles11.x86_64.rpm
4. Uncomment the entry you commented out in /etc/inittab.
5. Restart the Quorum Server:
/sbin/init q
Configuring Serviceguard to use the Quorum Server
About the QS polling interval and timeout extension
Serviceguard probes the Quorum Server at intervals determined by the QS_POLLING_INTERVAL
parameter in the cluster configuration file. The default value for QS_POLLING_INTERVAL is 5
minutes and the minimum value is 10 seconds.
If the quorum server process goes down while its node is still up, the Serviceguard cluster nodes
can detect the halt in the quorum server process. Serviceguard will try to reconnect to the quorum
server every 10 seconds until the quorum server is back up and the connection is successful. If the
quorum server is needed as a tie-breaker during this downtime, the cluster will halt.
However, Serviceguard cannot immediately detect the loss of connection to the process if the
quorum server’s node goes down. Serviceguard will continue to poll at the configured interval,
and will not discover that the quorum server connection is down until the next polling is done. If a
cluster reformation starts before the next polling has occurred, Serviceguard assumes the Quorum
Server is down. Because it requires the Quorum Server as a tie-breaker, it will halt the cluster. (Even
if the Quorum Server comes back up before or during reformation, Serviceguard will not know
that it has until the next polling.)
Reducing the QS_POLLING_INTERVAL means Serviceguard will detect Quorum Server failures
sooner, but it will also increase the load on the Quorum Server. If you set a short interval, you may
have to reduce the number of clusters or nodes using the Quorum Server to reduce the load. Test
very low settings carefully to fine-tune all timing parameters, and do the tests in an environment
that imitates the actual production environment as closely as possible.
You can use the optional QS_TIMEOUT_EXTENSION to increase the time interval (in microseconds)
after which the current connection (or attempt to connect) to the quorum server is deemed to have
failed; see “Network recommendations” (page 7) and “Setting Quorum Server parameters in the
cluster configuration file” (page 10).
Configuring Serviceguard to use the Quorum Server 9