Earlier snapshots are deleted after you restore multiple copy-on-write snapshots in consecutive order in Windows Vista or in Windows Server 2008

Consider the following scenario:
  • On a computer that is running Windows Server 2008 or Windows Vista, you configure a diff area on a volume. Additionally, you specify that snapshots will be created on another volume.
  • You create copy-on-write snapshots for a volume.
  • You restore these snapshots in order, from the latest snapshot to the earliest snapshot.
In this scenario, all earlier snapshots are deleted unexpectedly after the second snapshot is restored. Additionally, the following Error event is logged in the System log:
Event ID: 29
Source: volsnap
Type: Error
Description: The shadow copies of volume <drive letter> were aborted during detection.
When the Volume Shadow Copy driver (Volsnap.sys) reverts a volume to a selected snapshot, the snapshot that comes immediately before the selected snapshot becomes growable. Therefore, I/O requests for the volume will be updated in the diff area. However, the Volsnap.sys driver does not manage this process correctly. This behavior results in a corrupted diff area for the snapshots. Therefore, the remaining snapshots are deleted.

Hotfix information

A supported hotfix is now available from Microsoft. However, it is intended to correct only the problem that is described in this article. Apply it only to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

To resolve this problem immediately, contact Microsoft Customer Support Services to obtain the hotfix. For a complete list of Microsoft Customer Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.


To apply this hotfix, you must have one of the following operating systems installed on the computer.
  • Windows Vista Service Pack 1 (SP1)
  • Windows Vista Service Pack 2 (SP2)
  • Windows Server 2008
  • Windows Server 2008 Service Pack 2 (SP2)

Restart requirement

You have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

Registry information

To use one of the hotfixes in this package, you do not have to make any changes to the registry.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.Windows Vista and Windows Server 2008 file information notes
  • The files that apply to a specific product, milestone (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table:
    VersionProductMilestoneService branch
    6.0.6000.16xxxWindows VistaRTMGDR
    6.0.6000.20xxxWindows VistaRTMLDR
    6.0.6001.18xxxWindows Vista SP1 and Windows Server 2008 SP1SP1 GDR
    6.0.6001.22xxxWindows Vista SP1and Windows Server 2008 SP1SP1 LDR
    6.0.6002.18xxxWindows Vista SP2 and Windows Server 2008 SP2SP2GDR
    6.0.6002.22xxxWindows Vista SP2 and Windows Server 2008 SP2SP2LDR
  • Service Pack 1 is integrated into the original release version of Windows Server 2008. Therefore, RTM milestone files apply only to Windows Vista. RTM milestone files have a 6.0.0000.xxxxxx version number.
  • GDR service branches contain only those fixes that are widely released to address widespread, critical issues. LDR service branches contain hotfixes in addition to widely released fixes.
  • The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 and for Windows Vista" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are critical to maintaining the state of the updated component. The security catalog files (attributes not listed) are signed with a Microsoft digital signature.
For all supported x86-based versions of Windows Server 2008, of Windows Server 2008 SP2, of Windows Vista SP1, and of Windows Vista SP2
File nameFile versionFile sizeDateTimePlatform
Volume.infNot Applicable2,06218-Sep-200918:04Not Applicable
Volume.infNot Applicable2,06218-Sep-200907:43Not Applicable
For all supported x64-based versions of Windows Server 2008, of Windows Server 2008 SP2, of Windows Vista SP1, and of Windows Vista SP2
File nameFile versionFile sizeDateTimePlatform
Volume.infNot Applicable2,08218-Sep-200918:53Not Applicable
Volume.infNot Applicable2,08218-Sep-200907:43Not Applicable
For all supported IA-64-based versions of Windows Server 2008 and of Windows Server 2008 SP2
File nameFile versionFile sizeDateTimePlatform
Volume.infNot Applicable2,07218-Sep-200918:07Not Applicable
Volume.infNot Applicable2,07218-Sep-200907:42Not Applicable
To work around this issue, use one of following methods:
  • Method 1: Store the diff area on the same volume on which you create the snapshot.
  • Method 2: Between each copy-on-write snapshot in the sequence being restored, run the following command:
    vssadmin list shadowstorage /On=<drive letter>:
    Note The <drive letter> placeholder represents the volume that contains the diff area.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

Additional file information

Additional file information for Windows Server 2008 and for Windows Vista

Additional files for all supported x86-based versions of Windows Server 2008, of Windows Server 2008 SP2, of Windows Vista SP1, and of Windows Vista SP2
File nameFile versionFile sizeDateTimePlatform
Package_for_kb975803_client_1~31bf3856ad364e35~x86~~ Applicable1,36719-Sep-200906:54Not Applicable
Package_for_kb975803_client_2~31bf3856ad364e35~x86~~ Applicable1,69419-Sep-200906:54Not Applicable
Package_for_kb975803_client~31bf3856ad364e35~x86~~ Applicable1,71319-Sep-200906:54Not Applicable
Package_for_kb975803_sc_0~31bf3856ad364e35~x86~~ Applicable1,42119-Sep-200906:54Not Applicable
Package_for_kb975803_sc_1~31bf3856ad364e35~x86~~ Applicable1,69019-Sep-200906:54Not Applicable
Package_for_kb975803_sc~31bf3856ad364e35~x86~~ Applicable1,70119-Sep-200906:54Not Applicable
Package_for_kb975803_server_0~31bf3856ad364e35~x86~~ Applicable1,42519-Sep-200906:54Not Applicable
Package_for_kb975803_server_1~31bf3856ad364e35~x86~~ Applicable1,69419-Sep-200906:54Not Applicable
Package_for_kb975803_server~31bf3856ad364e35~x86~~ Applicable1,71319-Sep-200906:54Not Applicable
Package_for_kb975803_winpesrv_0~31bf3856ad364e35~x86~~ Applicable1,42219-Sep-200906:54Not Applicable
Package_for_kb975803_winpesrv~31bf3856ad364e35~x86~~ Applicable1,43019-Sep-200906:54Not Applicable
X86_volume.inf_31bf3856ad364e35_6.0.6001.22527_none_1631be12153c7876.manifestNot Applicable1,67119-Sep-200907:00Not Applicable
X86_volume.inf_31bf3856ad364e35_6.0.6002.22229_none_181a308e12610048.manifestNot Applicable1,67119-Sep-200907:00Not Applicable
Additional files for all supported x64-based versions of Windows Server 2008, of Windows Server 2008 SP2, of Windows Vista SP1, and of Windows Vista SP2
File nameFile versionFile sizeDateTimePlatform
Amd64_volume.inf_31bf3856ad364e35_6.0.6001.22527_none_72505995cd99e9ac.manifestNot Applicable1,67319-Sep-200907:08Not Applicable
Amd64_volume.inf_31bf3856ad364e35_6.0.6002.22229_none_7438cc11cabe717e.manifestNot Applicable1,67319-Sep-200907:08Not Applicable
Package_for_kb975803_client_1~31bf3856ad364e35~amd64~~ Applicable1,37519-Sep-200906:54Not Applicable
Package_for_kb975803_client_2~31bf3856ad364e35~amd64~~ Applicable1,70619-Sep-200906:54Not Applicable
Package_for_kb975803_client~31bf3856ad364e35~amd64~~ Applicable1,72319-Sep-200906:54Not Applicable
Package_for_kb975803_sc_0~31bf3856ad364e35~amd64~~ Applicable1,42919-Sep-200906:54Not Applicable
Package_for_kb975803_sc_1~31bf3856ad364e35~amd64~~ Applicable1,70219-Sep-200906:54Not Applicable
Package_for_kb975803_sc~31bf3856ad364e35~amd64~~ Applicable1,71119-Sep-200906:54Not Applicable
Package_for_kb975803_server_0~31bf3856ad364e35~amd64~~ Applicable1,43319-Sep-200906:54Not Applicable
Package_for_kb975803_server_1~31bf3856ad364e35~amd64~~ Applicable1,70619-Sep-200906:54Not Applicable
Package_for_kb975803_server~31bf3856ad364e35~amd64~~ Applicable1,72319-Sep-200906:54Not Applicable
Package_for_kb975803_winpesrv_0~31bf3856ad364e35~amd64~~ Applicable1,43019-Sep-200906:54Not Applicable
Package_for_kb975803_winpesrv~31bf3856ad364e35~amd64~~ Applicable1,43819-Sep-200906:54Not Applicable
Additional files for all supported IA-64-based versions of Windows Server 2008 and of Windows Server 2008 SP2
File nameFile versionFile sizeDateTimePlatform
Ia64_volume.inf_31bf3856ad364e35_6.0.6001.22527_none_16336208153a8172.manifestNot Applicable1,67219-Sep-200906:54Not Applicable
Ia64_volume.inf_31bf3856ad364e35_6.0.6002.22229_none_181bd484125f0944.manifestNot Applicable1,67219-Sep-200906:54Not Applicable
Package_for_kb975803_sc_0~31bf3856ad364e35~ia64~~ Applicable1,42519-Sep-200906:54Not Applicable
Package_for_kb975803_sc_1~31bf3856ad364e35~ia64~~ Applicable1,53019-Sep-200906:54Not Applicable
Package_for_kb975803_sc~31bf3856ad364e35~ia64~~ Applicable1,70619-Sep-200906:54Not Applicable
Package_for_kb975803_server_0~31bf3856ad364e35~ia64~~ Applicable1,42919-Sep-200906:54Not Applicable
Package_for_kb975803_server_1~31bf3856ad364e35~ia64~~ Applicable1,53319-Sep-200906:54Not Applicable
Package_for_kb975803_server~31bf3856ad364e35~ia64~~ Applicable1,71819-Sep-200906:54Not Applicable
Package_for_kb975803_winpesrv_0~31bf3856ad364e35~ia64~~ Applicable1,42619-Sep-200906:54Not Applicable
Package_for_kb975803_winpesrv~31bf3856ad364e35~ia64~~ Applicable1,43419-Sep-200906:54Not Applicable
COW Event ID: 29 event error shadow copy shadow copies volsnap.sys vxsnap.exe vshadow.exe snapshot loss data loss recovery fail

Article ID: 975803 - Last Review: 10/15/2009 07:53:25 - Revision: 1.1

Windows Vista Home Basic, Windows Vista Home Basic 64-bit Edition, Windows Vista Home Premium, Windows Vista Home Premium 64-bit Edition, Windows Vista Business, Windows Vista Business 64-bit Edition, Windows Vista Ultimate, Windows Vista Ultimate 64-bit Edition, Windows Vista Enterprise, Windows Vista Enterprise 64-bit Edition, Windows Vista Service Pack 1, Windows Vista Service Pack 2, Windows Server 2008 Datacenter without Hyper-V, Windows Server 2008 Enterprise without Hyper-V, Windows Server 2008 for Itanium-Based Systems, Windows Server 2008 Standard without Hyper-V, Windows Server 2008 Datacenter, Windows Server 2008 Enterprise, Windows Server 2008 Standard, Windows Web Server 2008

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