Recovering from a lost or corrupted quorum log (245762)

SYMPTOMS

The Cluster service may not start if a hardware failure occurs or power is lost to both nodes of a cluster and to the storage device known as the quorum on the shared device bus. In such cases, the following error message may occur when you attempt to start the Cluster service on the forming node of the server cluster:

Event ID: 1147
Source: ClusSvc
Description: The Microsoft Clustering Service encountered a fatal error. The vital quorum log file 'Q:\MSCS\quolog.log' could not be found. If you have a backup of the quorum log file, you may try to start the cluster service by entering 'clussvc -debug -noquorumlogging' at a command window, copy the backed up quorum log file to the MSCS directory in the quorum drive, stop the cluster service, and restart the cluster service normally using the 'net start clussvc' command. If you do not have a backup of the quorum log file, you may try to start the cluster service as 'clussvc -debug -resetquorumlog' and this will attempt to create a new quorum log file based on possibly stale information in the cluster hive. You may then stop the cluster service and restart it normally using the 'net start clussvc' command.

Important If this cluster is Windows 2000 Service Pack 4 (SP4)-based, and if the KB 872970 hotfix is installed, do not use the -ResetQuorumLog switch. Start the Cluster service normally.

CAUSE

This error message occurs if the quorum log file (Quolog.log) cannot be found or read at Cluster service startup. It must be readable to confirm that the cluster configuration on the local node is up-to-date. If it cannot read the log, the Cluster service does not start to prevent potentially loading stale configuration data.

RESOLUTION

If you have a backup of the system state on one of the computers after the last changes were made to the cluster, you can restore the quorum by restoring this information. For more information about backing up and restoring cluster configuration information, click the following article number to view the article in the Microsoft Knowledge Base:

248998 How to properly restore cluster information

If you do not have a backup of the Quorum log file, re-create a new quorum log file based on the cluster configuration information in the local system's cluster hive by starting the Cluster service with the -ResetQuorumLog switch. To do this, follow these steps:

Start the Services snap-in. (Click Start, point to Programs, click Administrative Tools, and then click Services.)
Right-click and select the properties of the Cluster service.
In the Start Parameters box, type:
-resetquorumlog

Then click the Start button.

If the error message occurs after you restore the system state on a computer that has lost the quorum log, the quorum information is copied to %SystemRoot%\Cluster\Cluster_backup. You can use the Clusrest.exe tool from the Resource Kit to restore this information to the quorum disk. For more information about Clusrest.exe and other useful Resource kit tools, see the Resource kit online Help.

MORE INFORMATION

Important If possible, perform the procedure that is described in this article from the node in the cluster that was known to have the latest configuration with regards to the resources that are contained in the cluster. If you had a node that has not been a member in the cluster since the time that the last changes, deletions, or additions were made to the cluster resources, that node will not have the latest configuration. Using this node with the -ResetQuorumLog switch could result in permanent loss of data, such as Resources or Resource Configurations.

The -ResetQuorumLog switch is new for Windows 2000. This switch is not available in Microsoft Windows NT 4.0. In Windows NT 4.0, if no quorum log is found, the Cluster service assumes that it is a new installation and creates the quorum log fresh from the local system information. It gets any updated cluster and program check points from the cluster nodes when they are brought online.

Important If this cluster is Windows 2000 SP4-based, and if the KB 872970 hotfix is installed, do not use the -ResetQuorumLog switch. Start the Cluster service normally.

REFERENCES

For more informationabout the KB 872970 hotfix, click the following article number to view the article in the Microsoft Knowledge Base:

872970 The quorum log file becomes corrupted in your Windows 2000 Advanced Server-based cluster environment