Configuring GAB manually

Last published : Jun 11, 2026
VCS uses the Group Membership Services/Atomic Broadcast (GAB) protocol for cluster membership and reliable cluster communications. GAB has two major functions.
It handles the following tasks:
  • Cluster membership
  • Cluster communications
To configure GAB
  1. Set up an /etc/gabtab configuration file on each node in the cluster using vi or another editor. The following example shows an /etc/gabtab file:
/sbin/gabconfig -c -nN
Where the -c option configures the driver for use. The -nN option specifies that the cluster is not formed until at least N systems are ready to form the cluster. Veritas recommends that you set N to be the total number of systems in the cluster.
Warning: Veritas does not recommend the use of the-c -xoption or-xoption for/sbin/gabconfig. Using-c -xor-xcan lead to a split-brain condition.
  1. Edit the following file on each node in the cluster to change the values of the GAB_START and the GAB_STOP environment variables to 1:
/etc/default/gab
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