Microsoft KB Archive/940252

= The Volume Shadow Copy Service may leak private bytes and virtual memory when you use the service to take frequent snapshots in Windows Server 2003 or in Windows XP =

Article ID: 940252

Article Last Modified on 10/11/2007

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APPLIES TO


 * Microsoft Windows Server 2003 R2 Standard Edition (32-bit x86)
 * Microsoft Windows Server 2003 R2 Enterprise Edition (32-Bit x86)
 * Microsoft Windows Server 2003 R2 Standard x64 Edition
 * Microsoft Windows Server 2003 R2 Enterprise x64 Edition
 * Microsoft Windows Server 2003, Standard Edition (32-bit x86)
 * Microsoft Windows Server 2003, Enterprise Edition
 * Microsoft Windows Server 2003, Web Edition
 * Microsoft Windows Server 2003, Standard x64 Edition
 * Microsoft Windows Server 2003, Enterprise x64 Edition
 * Microsoft Windows Server 2003, Enterprise Edition for Itanium-based Systems
 * Microsoft Windows XP Home Edition
 * Microsoft Windows XP Professional

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SYMPTOMS
The Volume Shadow Copy Service (VSS) may leak private bytes and virtual memory when you use the service to take frequent snapshots in Windows Server 2003 or in Windows XP.

To view the leaks in System Monitor, use the following performance counters under the Process object:
 * Private Bytes
 * Virtual Bytes



CAUSE
This problem occurs if the VSS software provider is unable to load snapshot objects. In this situation, the VSS software provider (Swprv.dll) does not release the allocated VSS_SNAPSHOT_PROP structures.



Hotfix information for Windows Server 2003
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 Windows Server 2003 Service Pack 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:

http://support.microsoft.com/contactus/?ws=support

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.

Prerequisites
To apply this hotfix, you must have Windows Server 2003 Service Pack 1 or Windows Server 2003 Service Pack 2 installed.

889100 How to obtain the latest service pack for Windows Server 2003

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

Hotfix replacement information
This hotfix does not replace any other hotfixes.

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.

Hotfix information for Windows XP
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 Windows XP service pack 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:

http://support.microsoft.com/contactus/?ws=support

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.

Prerequisites
To apply this hotfix, you must have an x64-based version of Windows XP Service Pack 1 or Windows XP Service Pack 2 installed.

322389 How to obtain the latest Windows XP service pack

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

Hotfix replacement information
This hotfix does not replace any other hotfixes.

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 XP Professional x64 Edition with Service Pack 1


STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.



Call stack output
When this issue occurs, the following call stack is generated: ntdll!RtlAllocateHeap+0x21d ole32!CRetailMalloc_Alloc+0x16 ole32!CoTaskMemAlloc+0x13 swprv!VssAllocString+0x13 swprv!CVssIOCTLChannel::UnpackSmallString+0x68 swprv!CVssQueuedSnapshot::LoadStructure+0x2ef swprv!CVsSoftwareProvider::InternalDeleteSnapshots+0x2df swprv!CVssQueuedSnapshot::~CVssQueuedSnapshot+0x12a swprv!CVssQueuedSnapshot::`scalar deleting destructor'+0xd swprv!CVssQueuedSnapshot::Release+0x27 swprv!CVsSoftwareProvider::RemoveSnapshotsFromGlobalList+0x17a swprv!CVsSoftwareProvider::~CVsSoftwareProvider+0x8d swprv!ATL::CComObject::~CComObject+0x4c swprv!ATL::CComObject::`scalar deleting destructor'+0xd swprv!ATL::CComObject::Release+0x27

Additional query words: VSS software provider leak memory

Keywords: kbqfe kbexpertiseinter kbhotfixserver KB940252

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