Use the setquorum command to change the managed disks (MDisks) that are assigned as quorum candidate disks.
Syntax
>>- svctask -- -- setquorum -- -- -quorum --+- 0 -+-- ----------> +- 1 -+ '- 2 -' >--+-----------+-- --+- mdisk_id ---+-------------------------->< '- -active -' '- mdisk_name -'
Parameters
- -quorum 0 | 1 | 2
- (Required) Specifies the quorum index.
- -active
- (Optional) Makes the specified MDisk the active quorum disk. To identify the quorum disk that is active, use the svcinfo lsquorum command.
- mdisk_id | mdisk_name
- (Required) Specifies the ID or name of the MDisk to assign as a quorum disk.
Description
The setquorum command sets the MDisk to the specified quorum index. This command is not synchronous, but usually takes only a few seconds to complete. In some situations it can take several minutes.
The cluster uses the quorum disk as a tie breaker when exactly half of the nodes that were previously a member of the cluster is present.
The use of a quorum disk allows the cluster to manage a SAN fault that splits the cluster exactly in half. One half of the cluster continues to operate and the other half stops until SAN connectivity is restored.
There is only one quorum disk; however, the cluster uses three disks as quorum candidate disks. The cluster selects the actual quorum disk from the pool of quorum candidate disks. The quorum candidate disks also hold a copy of important cluster metadata. Just over 256 MB is reserved for this purpose on each quorum candidate disk. The number of extents this reservation requires depends on the extent size for the managed disk group containing the MDisk. Table 1 provides the number of extents reserved for quorum use by extent size.
| Extent size (MB) | Number of extents reserved for quorum use |
|---|---|
| 16 | 17 |
| 32 | 9 |
| 64 | 5 |
| 128 | 3 |
| 256 | 2 |
| 512 | 1 |
| 1024 | 1 |
| 2048 | 1 |
When you issue this command, the MDisk that currently is assigned the quorum index number is set to a nonquorum disk. The cluster automatically assigns quorum indexes.
You can set the active quorum disk with the active parameter. This can be useful in a split-site cluster configuration to ensure that the most highly-available quorum disk is used.
An invocation example
svctask setquorum -quorum 2 mdisk7
The resulting output
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