HP Serviceguard Quorum Server Version A.03.00 Release Notes, December 2007

HP Serviceguard Quorum Server Version A.03.00 Release Notes
Configuring Serviceguard to Use the Quorum Server
Chapter 1 19
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” on page 11 and “Setting Quorum Server Parameters
in the Cluster Configuration File” on page 20.
Using Alternate Subnets
Some versions of Serviceguard (see “Compatibility with Serviceguard
Versions” on page 12) support new functionality in the Quorum Server
that allows you to configure more than one subnet on which
communication between the Quorum Server and the cluster nodes can
take place.
In this case, you configure a primary subnet (indicated by the QS_HOST
parameter in the cluster configuration file) and an alternate subnet
(indicated by the QS_ADDR entries in the cluster configuration file).
If communication between a cluster node and the Quorum Server fails
(or cannot be established in the first place) on the primary subnet, the
cluster node will try the alternate QS_ADDR listed in the configuration
file.
In the meantime, the node will mark the Quorum Server DOWN and you
will see the status as DOWN in the cmviewcl output. The log will show the
IP address of the failed connection, with the key word timedout if the
Quorum Server has been marked DOWN because of a timeout. If the
connection to the alternate subnet succeeds, the status will change to UP,
and the log will show that the connection succeeded on the alternate
subnet. Corresponding messages are written to syslog.
NOTE You can use cmviewcl -v at any time to check the status of the Quorum
Server connection, but you cannot see from the output which subnet is
being used, and there is no way to check the status of each connection
individually.
Requirements for Using Alternate Subnets
All of the following must be true in order for you to configure more than
one subnet for communication between the Quorum Server and the
cluster nodes: