Event ID 1573 — Cluster Witness Functionality

Applies To: Windows Server 2008

In a cluster with an even number of nodes and a quorum configuration that includes a witness, when the witness remains online, the cluster can sustain failures of half the nodes. If the witness goes offline, the same cluster can sustain failures of half the nodes minus one.

Event Details

Resolve

Confirm witness accessibility

If you are not sure whether the cluster quorum configuration includes a witness disk or a witness file share, see "Viewing the quorum configuration of a failover cluster." Then confirm that the witness disk or witness file share is online. For more information about viewing the status of a witness disk, see "Viewing the status of a witness disk in a failover cluster that uses a quorum configuration of Node and Disk Majority."

If you do not currently have Event Viewer open, see "Opening Event Viewer and viewing events related to failover clustering."

To perform these procedures, you must be a member of the local Administrators group on each clustered server, and the account you use must be a domain account, or you must have been delegated the equivalent authority.

Viewing the quorum configuration of a failover cluster

To view the quorum configuration of a failover cluster:

1. To open the failover cluster snap-in, click Start, click Administrative Tools, and then click Failover Cluster Management. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.

2. In the Failover Cluster Management snap-in, if the cluster you want to manage is not displayed, in the console tree, right-click Failover Cluster Management, click Manage a Cluster, and then select or specify the cluster that you want.

3. In the console tree, ensure that the cluster is selected.

4. In the center pane, near the top, view the Quorum Configuration.

   If the Quorum Configuration is Node and Disk Majority, the cluster uses a witness disk. If it is Node and File Share Majority, the cluster uses a witness file share.

Viewing the status of a witness disk in a failover cluster that uses a quorum configuration of Node and Disk Majority

To view the status of a witness disk in a failover cluster that uses a quorum configuration of Node and Disk Majority:

1. To open the failover cluster snap-in, click Start, click Administrative Tools, and then click Failover Cluster Management. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.

2. In the Failover Cluster Management snap-in, if the cluster you want to manage is not displayed, in the console tree, right-click Failover Cluster Management, click Manage a Cluster, and then select or specify the cluster that you want.

3. If the console tree is collapsed, expand the tree under the cluster you want to manage, and then expand Storage.

4. In the center pane, under Witness Disk in Quorum, view the status of the witness disk, and expand the listing to view the percentage of free space on the disk.

   If the cluster does not use a quorum configuration of Node and Disk Majority, no listing will appear for a witness disk.

Opening Event Viewer and viewing events related to failover clustering

To open Event Viewer and view events related to failover clustering:

1. If Server Manager is not already open, click Start, click Administrative Tools, and then click Server Manager. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.
2. In the console tree, expand Diagnostics, expand Event Viewer, expand Windows Logs, and then click System.
3. To filter the events so that only events with a Source of FailoverClustering are shown, in the Actions pane, click Filter Current Log. On the Filter tab, in the Event sources box, select FailoverClustering. Select other options as appropriate, and then click OK.
4. To sort the displayed events by date and time, in the center pane, click the Date and Time column heading.

Verify

Verify that the Cluster service starts on the nodes in the cluster. If the quorum configuration uses a witness, verify that the witness is online and accessible.

To perform these procedures, you must be a member of the local Administrators group on each clustered server, and the account you use must be a domain account, or you must have been delegated the equivalent authority.

Verifying that the Cluster service starts on the nodes in a failover cluster

To verify that the Cluster service starts on the nodes in a failover cluster:

1. To open the failover cluster snap-in, click Start, click Administrative Tools, and then click Failover Cluster Management. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.
2. In the Failover Cluster Management snap-in, if the cluster you want to manage is not displayed, in the console tree, right-click Failover Cluster Management, click Manage a Cluster, and then select or specify the cluster that you want.
3. If the console tree is collapsed, expand the tree under the cluster you want to manage, and then click Nodes.
4. View the status for each node. If a node is not Up, to start the Cluster service on it, right-click the node, click More Actions, and then click Start Cluster Service.

Viewing the status of a witness disk in a failover cluster that uses a quorum configuration of Node and Disk Majority

To view the status of a witness disk in a failover cluster that uses a quorum configuration of Node and Disk Majority:

1. To open the failover cluster snap-in, click Start, click Administrative Tools, and then click Failover Cluster Management. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.

2. In the Failover Cluster Management snap-in, if the cluster you want to manage is not displayed, in the console tree, right-click Failover Cluster Management, click Manage a Cluster, and then select or specify the cluster that you want. (To confirm that the quorum configuration is Node and Disk Majority, in the center pane, near the top, view the Quorum Configuration.)

3. If the console tree is collapsed, expand the tree under the cluster you want to manage, and then expand Storage.

4. In the center pane, under Witness Disk in Quorum, view the status of the witness disk, and expand the listing to view the percentage of free space on the disk.

   If the cluster does not use a quorum configuration of Node and Disk Majority, no listing will appear for a witness disk.

Related Management Information

Cluster Witness Functionality

Failover Clustering