Managing HP Serviceguard for Linux Ninth Edition, April 2009

and begins re-forming the cluster without this
node.
Default value: 14 seconds (14,000,000
microseconds).
This value leads to a failover time of between
approximately 18 and 22 seconds, if you are using
a quorum server, or a Fiber Channel cluster lock,
or no cluster lock. Increasing the value to 25
seconds increases the failover time to between
approximately 29 and 39 seconds. The time will
increase by between 5 and 13 seconds if you are
you using a SCSI cluster lock or dual Fibre
Channel cluster lock).
Maximum supported value: 300 seconds
(300,000,000 microseconds).
If you enter a value greater than 60 seconds
(60,000,000 microseconds), cmcheckconf and
cmapplyconf will note the fact, as confirmation
that you intend to use a large value.
Minimum supported values:
• 3 seconds for a cluster with more than one
heartbeat subnet.
• 14 seconds for a cluster that has only one
heartbeat LAN
With the lowest supported value of 3 seconds, a
failover time of 4 to 5 seconds can be achieved.
NOTE: The failover estimates provided here
apply to the Serviceguard component of failover;
that is, the package is expected to be up and
running on the adoptive node in this time, but
the application that the package runs may take
more time to start.
Keep the following guidelines in mind when
deciding how to set the value.
Guidelines: You need to decide whether it's more
important for your installation to have fewer (but
slower) cluster re-formations, or faster (but
possibly more frequent) re-formations:
112 Planning and Documenting an HA Cluster