Veritas Storage Foundation 5.1 SP1 for Oracle RAC Administrator"s Guide (5900-1512, April 2011)

Warning: Do not adjust the SF Oracle RAC tunable parameters for LMX and VXFEN
as described below to enhance performance without assistance from Symantec
support personnel.
About GAB tunable parameters
GAB provides various configuration and tunable parameters to modify and control
the behavior of the GAB module.
These tunable parameters not only provide control of the configurations like
maximum possible number of nodes in the cluster, but also provide control on
how GAB behaves when it encounters a fault or a failure condition. Some of these
tunable parameters are needed when the GAB module is loaded into the system.
Any changes to these load-time tunable parameter require either unload followed
by reload of GAB module or system reboot. Other tunable parameters (run-time)
can be changed while GAB module is loaded, configured, and cluster is running.
Any changes to such a tunable parameter will have immediate effect on the tunable
parameter values and GAB behavior.
These tunable parameters are defined in the following file:
/etc/rc.config.d/gabconf
See “About GAB load-time or static tunable parameters” on page 244.
See “About GAB run-time or dynamic tunable parameters” on page 246.
About GAB load-time or static tunable parameters
Table 5-1 lists the static tunable parameters in GAB that are used during module
load time. Use the gabconfig -e command to list all such GAB tunable parameters.
You can modify these tunable parameters only by adding new values in the GAB
configuration file. The changes take effect only on reboot or on reload of the GAB
module.
Table 5-1
GAB static tunable parameters
Values (default
and range)
DescriptionGAB parameter
Default: 64
Range: 1-64
Maximum number of nodes in the
cluster
numnids
Default: 32
Range: 1-32
Maximum number of ports in the
cluster
numports
Tunable parameters
About GAB tunable parameters
244