Node quorum with tiebreaker considerations
Node quorum with tiebreaker disks allows you to run with as few as one quorum node available as long as you have access to a majority of the quorum disks. Enabling node quorum with tiebreaker disks starts by designating one or more nodes as quorum nodes. Then one to three disks are defined as tiebreaker disks using the tiebreakerDisks parameter on the mmchconfig command. You can designate any disk to be a tiebreaker. When utilizing node quorum with tiebreaker disks, there are specific rules for cluster nodes and for tiebreaker disks.
For more information on node quorum with tiebreaker, see Quorum.
When using node quorum with tiebreaker, define one, two, or three
disks to be used as tiebreaker disks when any quorum node is down.
Issue this command:
mmchconfig tiebreakerDisks="nsdName;nsdName;nsdName"Consider these points:
- You are not permitted to change a GPFS cluster configuration to use node quorum with tiebreaker if there are more than eight existing quorum nodes.
- You can have a maximum of three tiebreaker disks.
- The disks must be directly attached to all quorum nodes.
- When adding tiebreaker disks:
- If the tiebreaker disks are part of a file system, GPFS should be up and running.
- If the tiebreaker disks are not part of a file system, GPFS can be either running or shut down.
- When using the traditional server-based (non-CCR) configuration repository, the GPFS daemons must be down on all nodes in the cluster when running mmchconfig tiebreakerDisks.
If you are using node quorum with tiebreaker and want to change
to using node quorum, issue this command:
mmchconfig tiebreakerDisks=DEFAULT