Scott Alan Miller

Tuesday, September 06, 2005

Disk Expansion on Windows Server 2000 Cluster with SAN

Issue: A Windows 2000 Advanced Server Cluster running an MS SQL 2000 database using a Storage Area Network (SAN.) The current logical drive on the SAN needs to be expanded. This cannot be accomplished using standard Windows 2000 tools because Windows 2000 Server does not support resizing of Basic volumes and it also does not support the use of Dynamic volumes in a cluster (or at least they are highly not recommended.)

Solution: With the release of Windows XP and Windows Server 2003, Microsoft offers a disk resizing utility called DiskPart.exe. This utility is designed around Microsoft’s “just in time” storage model and makes up for the deficiencies found in early Microsoft products. Diskpart.exe allows for drive resizing on both Basic and Dynamic volumes and, most importantly, supports usage on SANs. Diskpart is a command line utility and is scriptable if the operation is expected to be performed repeatedly.

There are some basic limitations to Diskpart. Most notably, the file system on the volume to be resized must be NTFS and must not have been converted from FAT32. Volumes can only be extended. They cannot be reduced in size. On Basic volumes which includes any use with a SAN, the unallocated space must be the next contiguous space on the same disk.

Diskpart is available as a free download for Windows 2000 Server.

Information on using Diskpart can be found at Knowledge Base article 325590.