Manual seeding of a cluster

Seeding the cluster manually is appropriate when the number of cluster systems declared in /etc/gabtab is more than the number of systems that will join the cluster.

This can occur if a system is down for maintenance when the cluster comes up.

Warning:

It is not recommended to seed the cluster manually unless the administrator is aware of the risks and implications of the command.

Note:

If you have I/O fencing enabled in your cluster, you can set the GAB auto-seeding feature through I/O fencing so that GAB automatically seeds the cluster even when some cluster nodes are unavailable.

See Seeding a cluster using the GAB auto-seed parameter through I/O fencing.

Before manually seeding the cluster, check that systems that will join the cluster are able to send and receive heartbeats to each other. Confirm there is no possibility of a network partition condition in the cluster.

Before manually seeding the cluster, do the following:

To manually seed the cluster, type the following command:

/sbin/gabconfig -x

Note there is no declaration of the number of systems in the cluster with a manual seed. This command will seed all systems in communication with the system where the command is run.

So, make sure not to run this command in more than one node in the cluster.

More Information

Seeding and I/O fencing