Event ID 4001 — VSS Shadow Copy Creation and Storage Space Availability

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Applies To: Windows Server 2008 R2

A shadow copy is a snapshot of a volume that duplicates all of the data that is held on that volume at one well-defined instant in time.

Event Details

Product: Windows Operating System
ID: 4001
Source: VSS
Version: 6.1
Symbolic Name: VSS_ERROR_NO_DIFF_AREAS_CANDIDATES
Message: Volume Shadow Copy Service error: Cannot find diff areas for creating shadow copies. Please add at least one NTFS drive to the system with enough free space. The free space needed is at least 300 Mb for each volume to be shadow copied.

Resolve

Check the shadow copy storage area configuration

This event indicates that the Volume Shadow Copy Service (VSS) could not find enough disk space to successfully create a shadow copy.

Possible resolutions include:

  • Check the shadow copy storage area configuration and determine whether it needs to be changed.
  • If necessary, move the shadow copy storage area (also called the "diff area") to a different volume.
  • Check the volume that contains the shadow copy storage area for errors or hardware issues.

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

Check the volume shadow copy storage area configuration and determine whether it needs to be changed

To check the volume shadow copy storage area configuration and determine whether it needs to be changed:

  1. Open an elevated Command Prompt window. Click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
  2. Type vssadmin list shadowstorage, and then press Enter. The command output lists the volume shadow copy storage space that is currently being used, the space that is allocated for future use, and the maximum space that could be used.
  3. If the volume shadow copy storage space that is currently being used is almost as large as the maximum, consider moving the volume shadow copy storage area to a different, dedicated volume to improve performance. For more information, see the "Move the volume shadow copy storage area to a different volume" section.

For more information about the vssadmin command, see https://go.microsoft.com/fwlink/?LinkId=103401. For information about managing shadow copy storage space, see "Shadow Copy Space Management" in https://go.microsoft.com/fwlink/?LinkId=157113.

Move the volume shadow copy storage area to a different volume

To move the volume shadow copy storage area to a different volume:

Caution: When you change the location of the shadow copy storage area, all previous shadow copies are deleted.

Note: To successfully create a shadow copy, at least one NTFS file system volume is required with at least 320 MB of free space. (The message for this event states that the minimum size is 300 MB, but the correct minimum size is 320 MB.) Do not store the volume shadow copy storage area on a storage device that can be easily removed from the computer. Do not store the volume shadow copy storage area on a storage device that may not be available to Windows until late in the system startup sequence. For example, a logical unit number (LUN) created on an Internet SCSI (iSCSI) storage subsystem might not appear until a software initiator has started.

  1. Click Start, and then click Computer.

  2. Right-click any of the volumes listed, and then click Configure Shadow Copies.

  3. Click the volume that is currently used for the volume shadow copy storage area, 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 volume shadow copy area volume to a volume with more storage capacity by selecting the volume from the drop-down list under Storage area, and then click OK.

  5. Ensure 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.

Check the volume that contains the shadow copy storage area for errors or hardware issues

To check the volume that contains the shadow copy storage area for errors or hardware issues:

  1. Click Start, click Run, type diskmgmt.msc, and then click OK.
  2. In Disk Management, click View, click Top, and then select Disk List.
  3. In Disk Management, click View, click Bottom, and then select Volume List.
  4. Ensure that Disk Management displays an Online status for fixed disks and a Healthy status for volumes. For disk status descriptions, see https://go.microsoft.com/fwlink/?LinkId=103403. For volume status descriptions, see https://go.microsoft.com/fwlink/?LinkId=103404.

Verify

To verify that the Volume Shadow Copy Service (VSS) can create a volume shadow copy, perform the following procedure, and then retry the previous VSS operation.

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

To verify that the VSS service can correctly create a volume shadow copy of the system volume:

  1. Open an elevated Command Prompt window. Click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
  2. Type diskshadow, and then press Enter.
  3. Type add volume <Volume>, where Volume is the drive letter for the system volume, and then press Enter.
  4. Type create, and then press Enter.

For more information about the DiskShadow tool, including usage examples, see https://technet.microsoft.com/en-us/library/cc772172.aspx.

VSS Shadow Copy Creation and Storage Space Availability

File Services