Conflicting Mapped Drives and Folders May Cause Cluster Failure or Mapping Loss (303948)

SYMPTOMS

If you log on to a Cluster service as a user whose home directory mapping is configured as the same drive letter as one of the physical disk resources, the disk resource and all dependent resources may not work. The system log may log one or more of the following event messages:

Event: 1066
Source: clussvc
Description: Cluster Disk resource Disk X: is corrupt. Running ChkDsk /F to repair problems.

Event: 1035
Source: clussvc
Description: Cluster disk resource 'Disk X:' could not be mounted.

Event: 1069
Source: clussvc
Description: Cluster disk resource 'Disk X:' failed.

The following is logged in Cluster.log:

2002/07/10-13:36:28.944 Physical Disk <Disk X:>: DiskspCheckPath:
GetFileAttrs(X:) returned status of 5

2002/07/10-13:36:28.944 Physical Disk <Disk X:>: DiskspCheckPath:
DCPI(X:) returned status of 5, files scanned 0.

2002/07/10-13:36:28.944 Physical Disk <Disk X:>: DiskpCheckPath
for X: returned status = 5

CAUSE

This problem occurs because drive letter mapping for the home folder succeeds and causes a conflict with the drive letter mapping for the physical disk. Therefore, the storage device loses the drive letter and causes the failure of the physical disk resource to occur. On a stand-alone server, similar behavior may occur if a home folder mapping conflicts with the drive letter mapping of a storage device. In this scenario, the storage device loses the drive letter assignment and the home folder mapping succeeds; the storage device becomes inaccessible. If the physical disk resource is the quorum resource, the Cluster service may stop working.

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

260910 How to Obtain the Latest Windows 2000 Service Pack

The English-language version of this fix should have the following file attributes or later:

   Date        Time    Version        Size     File name
   ------------------------------------------------------
   07/27/2001  01:38p  5.0.2195.3963  332,560  Msgina.dll

WORKAROUND

To work around this problem, avoid the drive letter mapping conflict by selecting drive letters for the physical disk resources that do not conflict with the automatic mapping for home folders. When you map a drive manually, the operating system only offers unused drive letters for selection.

NOTE: On a Windows Clustering server, drive letters may be listed as available even when they are already mapped to drives by another node in the cluster. The symptoms that are described at the beginning of this article apply to clustered systems that are running versions of Microsoft Windows 2000 that are earlier than Windows 2000 Service Pack 3 (SP3). To resolve this problem, and to guarantee the highly available status of clustered systems, Windows 2000 SP3 implements changes that ensure the cluster service's ability to maintain ownership of the drive mappings that it requires. After you install Windows 2000 SP3, when a cluster fails resources to an available node, the cluster service takes any drive letter that it requires to continue cluster function, even at the expense of resource mapping. For example, if Q is the drive letter of the quorum resource, and Q is mapped to a network share and a failover occurs, the cluster service immediately terminates the share mapping and assumes ownership of the Q mapping for the cluster resource. If job processes are running on the share mapping, you may experience data loss or data corruption.

This workaround applies to clustered systems that are earlier than Windows 2000 SP3 in addition to clustered systems that are running Windows 2000 SP3 and later. Microsoft recommends that you do not map drive letters that are used by any node in the cluster on any other node in a cluster.