How to extend the partition of a cluster shared disk

This article describes how to add additional storage capacity to a server cluster if the underlying hardware RAID supports "capacity extension" technology. Capacity extension provides the ability to add additional drives to an existing RAID set and extend the logical drive so that it appears as free space at the end of the same logical drive. You can use the Diskpart.exe command-line utility to extend an existing partition into free space. This process has the following requirements:

• The additional disk space must appear as free space at the end of the existing drive, and it must be directly behind the existing volume that is to be extended.
• The extension must not rely on software fault tolerance to combine the existing partition and free space.
• The disk signatures of the existing drive remain the same.
• Use of the Physical Disk Resource type for the disk. If the disk resource is provided by a third-party manufacturer, you must contact that manufacturer for information about how to increase disk space.

IMPORTANT: If you add an additional drive to an existing array and the new drive appears as a new logical disk (instead of free space at the end of the existing drive), the hardware does not support capacity extension because it refers to the free space as a new drive, and the following procedure will not work. Some storage hardware will, by default, automatically create a new logical disk and volume for the new space despite the fact that the expansion of the existing logical disk is a possible option. When you are using server clusters, software fault tolerance is not natively supported, and the creation of a spanned volume (Volume Set) is not a viable option. To add additional space:

• Create a second physical disk resource.
• Delete and then re-create the array with the additional disk, and then replace the disk by using the instructions that are included in the following Microsoft Knowledge Base article:

To obtain the Diskpart.exe utility for Windows 2000, download "Diskpart.exe: Diskpart Command Line Utility" from the following Microsoft Windows 2000 Resource Kit Web site: An older version of the Diskpart.exe utility was previously released on the Resource Kit Web site. To verify that you have the correct version of the Diskpart file, install the package, right-click the file, and then click Properties. Then, start Diskpart.exe and verify that the version matches or is greater than "5.1.3553".

NOTE: Older versions of the Diskpart.exe file have a file version of either 0.52 or 1.0.

If you want to extend the disk space for a shared disk on a Microsoft Windows NT 4.0 Cluster, use the instructions that are included in the following Microsoft Knowledge Base article: NOTE: Diskpart.exe version 5.2.3790 is included with Windows Server 2003.

How to Extend an Existing Drive into Free Space if the Hardware Supports Capacity Extension

We recommend the following procedure for performing an offline extension of the partition during a scheduled maintenance window. You can also extend volumes that are online. (In that case, steps 2 and 3 are optional.) Before you perform an online extension of a production partition, we recommend that you test the specific hardware environment and hardware configuration to confirm that it will behave correctly.

1. Back up the shared disk (or disks) that that you want to extend.
2. Power off all but one node in the cluster.
3. Take the entire group that the physical disk resource is located in offline. Bring only the physical disk resource that is to be extended online. This process should close any open handles to the disk.
   
   NOTE: If you have any disk or Host Bus Adapter (HBA) utilities that access the disk, you may need to quit them or stop the services so that they will release any handles to the disk.
4. Add the additional physical drives and extend the additional disk or disks as free space by using the instructions that are included with the hardware vendor documentation.
5. Click All Programs, point to Administrative Tools, click Computer Management, and then start the Disk Management console. Verify that the new free space is added to the end of the proper drive. Right-click the existing partition, and then click Properties. On the General tab, type a unique name for the partition. This name will be used to identify the partition you want to extend in Diskpart.exe. Quit Computer Management.
   
   NOTE If you encounter any problems with the preceding two steps while you are extending the drive, contact your hardware vendor for assistance.
6. At a command prompt, type DISKPART, and then press ENTER to start Diskpart.exe.
7. Type LIST VOLUME, and then press ENTER to display the existing volumes on the computer.
8. Type SELECT VOLUME volume number, and then press ENTER, where volume number is the number of the volume that you want to extend. Note that the volume will have the unique name that you created in step 5, and will have been listed in the output of the command you ran in step 7.
9. Type EXTEND, and then press ENTER to extend the partition into all of the available disk space to the end of the drive.
10. Type EXIT, and then press ENTER.
11. Now that the volume has been extended, you can bring the entire group that contains the physical disk resource online, and then power up all of the other nodes in the cluster.
12. Verify that the group can come online and failover to all other nodes in the cluster.