Symantec 5 Configuring GAB when adding a node to a single node cluster, Starting LLT and GAB

Installing VCS on a single node 149

Adding a node to a single-node cluster

Configuring GAB when adding a node to a single node cluster

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, use vi or another editor to set up an /etc/gabtab configuration file on each node in the cluster. The following example shows an /etc/gabtab file:

/sbin/gabconfig -c -nN

The -coption configures the driver for use. The -nNspecifies that the cluster is not formed until at least N systems are ready to form the cluster. By default, N is the number of systems in the cluster.

Note: Symantec does not recommend the use of the -c-xoption for /sbin/gabconfig. Using -c-xdramatically increases configuration time for the Gigabit Ethernet controller and can lead to a split-brain condition.

Starting LLT and GAB

On the new node, start LLT and GAB.

To start LLT and GAB

1Start LLT on Node B.

# /etc/init.d/llt start

2Start GAB on Node B.

# /etc/init.d/gab start

Reconfiguring VCS on the existing node

Reconfigure VCS on the existing nodes.