Event ID 41 — Diff Area Integrity

Applies To: Windows Server 2008 R2

The Diff Area is the storage space that Shadow Copies of Shared Folders allocates on a volume for maintaining the snapshots of the contents of shared folders. A snapshot is a block-level set of information that represents the differences between the current content and content from a previous point in time. The integrity of existing and new snapshots depends on the integrity of the Diff Area.

Event Details

Product: Windows Operating System
ID: 41
Source: VolSnap
Version: 6.1
Symbolic Name: VS_INITIAL_DEFRAG_FAILED_STRICT_FRAGMENTATION
Message: When preparing a new volume shadow copy for volume %2, the shadow copy storage on volume %3 did not have sufficiently large contiguous blocks.  Consider deleting unnecessary files on the shadow copy storage volume or use a different shadow copy storage volume

Resolve

Free up space on the volume or move the Diff Area to a different volume

You need to free up space on the volume where the Diff Area is stored by deleting unnecessary files or by extending the volume. For more information about extending the volume, see the "Extend the volume" section. If you cannot delete files or extend the volume, or if you continue to have the same problem with shadow copies, then you need to move the Diff Area to a different volume. For more information, see the "Move the Diff Area to a different volume" section.

To perform these procedures, you must have membership in Administrators, or you must have been delegated the appropriate authority.

Extend the volume

To extend the volume where the Diff Area is stored:

  1. Open Server Manager. Click Start, point to Administrative Tools, and then click Server Manager.

  2. In the Server Manager console tree, expand Storage, and then click Disk Management.

  3. Right-click the volume where the shadow copies are stored (i.e. the Diff Area), as reported in the event log message, and then click Extend Volume.

    Note: If the Extend Volume option is not available, then that volume cannot be extended. In this case, you must try to delete unnecessary files, or you need to move the Diff Area to a different volume.

  4. Follow the steps in the Extend Volume Wizard pages.

Move the Diff Area to a different volume

To move the Diff Area to a different volume:

Caution: When you change the location of the Diff Area, all previous shadow copies are deleted. Follow this procedure only if you have already tried deleting unnecessary files or extending the volume—or if shadow copies continue to fail.

  1. Click Start, and then click Computer.

  2. Right-click any of the volumes listed, and then click Configure Shadow Copies. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.

  3. Click the volume for which the shadow copy failed, and then click Settings.

    Note: If shadow copies of the volume are enabled, you must first disable them by clicking the volume, and then clicking Disable.

  4. Set the Diff Area to a different volume by selecting a volume from the drop-down list under Storage area, and then click OK.

  5. Verify that the volume is still selected and click Enable. If you are asked to confirm that you want to enable shadow copies, click Yes.

  6. Click OK to exit.

Verify

The Diff Area is working correctly if a new shadow copy can be successfully created.

To perform this procedure, you must have membership in Administrators, or you must have been delegated the appropriate authority.

To create a new shadow copy:

  1. Click Start, and then click Computer.

  2. Right-click any of the volumes listed, and then click Configure Shadow Copies. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.

  3. Click the volume that you want to create a new shadow copy of, and then click Create Now. The Diff Area is working correctly if the new shadow copy is listed under Shadow copies of selected volume.

    Note: Depending on the size of the volume and the number of changes that have occurred since the last shadow copy, creating the new shadow copy can take a few seconds or several minutes.

Diff Area Integrity

File Services