Q. How can I change a Windows Server 2008 cluster quorum from the command line?

A. You can use the cluster.exe command to change a cluster’s quorum mode. To view the existing quorum mode for a cluster, you use the following command (in the format cluster cluster name /quorum), as follows:

C:>cluster savdalclusfs01 /quorum

You’ll get this output:

To change the quorum mode, you add a resource for the type of quorum mode you want—for example, a file-share witness—as follows. (Both the commands you enter and their output are shown.)

C:>cluster /cluster:savdalclusfs01 res "File Share Witness" /create /group:"Cluster Group" /type:"File Share Witness" /priv SharePath=\savdaldc02fsw

Creating resource 'File Share Witness'...

C:>cluster /cluster:savdalclusfs01 res "File Share Witness" /online

Bringing resource 'File Share Witness' online...

C:>cluster savdalclusfs01 /quorum:"File Share Witness"

Notice we add the file share as a resource, bring the new resource online, then tell the cluster to use that resource for the quorum. Unlike the procedure for changing the cluster quorum via the Microsoft Management Console (MMC) Failover Cluster Management snap-in, you must give the cluster computer object, and not the administrator, full control on the share. That is, for my cluster I must add account savdalclusfs01$ with full control to the share fsw on server savdaldc02.

To change quorum to a disk witness, you need to move a disk resource into the cluster group, like this:

C:>cluster res "Quorum Disk" /move:"Cluster Group"

Moving resource 'Quorum Disk' to group 'Cluster Group'...

Now you need to tell the cluster to use the disk for the quorum:

C:>cluster /quorum:"Quorum Disk"

Note that if you add /disk to the end of the command, you tell the cluster to use disk only and not Node and Disk Majority (the normal mode).

C:>cluster /quorum:"Quorum Disk" /disk

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You can switch to Node Majority only by running the following command:

C:>cluster /quorum /node

The screencast below takes you through using the command line to perform this and other Server 2008 cluster-configuration tasks.