DOCUMENT:Q249148 01-JUN-2001 [exchange] TITLE :XADM: Handles Leak During Online Backup PRODUCT :Microsoft Exchange PROD/VER:winnt:5.5 SP3 OPER/SYS: KEYWORDS:exc55sp3 kbExchange550preSP4fix kbExchange550sp4Fix kbgraphxlinkcritical ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Exchange Server, version 5.5 SP3 ------------------------------------------------------------------------------- SYMPTOMS ======== If you monitor the Exchange Server computer by using Performance Monitor, you find that many handles leaked after an online backup. CAUSE ===== Several registry keys are opened during an online backup. Some of them come from the Mdbrest.dll file. After the query, the keys are not closed. They remain open for later use for performance reasons. But if the Mdbrest.dll has been relocated because of a memory address collision, those keys are not closed. They are reopened, and the previous handles leak when they are queried again. RESOLUTION ========== To resolve this problem, obtain the latest service pack for Exchange Server 5.5. For additional information, please see the following article in the Microsoft Knowledge Base: Q191014 XGEN: How to Obtain the latest Exchange Server 5.5 Service Pack The following files are available for download from the Microsoft Download Center: x86: DownloadDownload Q248838engi.exe now (http://www.microsoft.com/downloads/release.asp?ReleaseID=25443) Alpha: DownloadDownload Q248838enga.exe now (http://www.microsoft.com/downloads/release.asp?ReleaseID=25444) For additional information about how to download Microsoft Support files, click the article number below to view the article in the Microsoft Knowledge Base: Q119591 How to Obtain Microsoft Support Files from Online Services Microsoft used the most current virus detection software available on the date of posting to scan this file for viruses. Once posted, the file is housed on secure servers that prevent any unauthorized changes to the file. STATUS ====== Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 5.5. This problem was first corrected in Exchange Server 5.5 Service Pack 4. MORE INFORMATION ================ If you use CDB to attach to the Mad.exe file, the following information is displayed: LDR: Automatic DLL relocation in Mad.exe LDR: Dll mdbrest.dll base 004b0000 relocated due to collision with Dynamically Allocated Memory CDB ModLoad: 0b950000 0b982000 Mdbrest.dll CDB ModLoad: 6fcc0000 6fcd4000 C:\Exchsrvr\Bin\Netif.dll CDB ModLoad: 6fcb0000 6fcb8000 C:\Exchsrvr\Bin\Isatq.dll If you use the Oh.exe file to check the handles that are held by the Mad.exe file, you find that the leaked handles are from the following key: HKEY_LOCAL_MACHINE\SYSTEM\CCS\Service\MSExchangeIS\ParametersPrivate The fix closes all such keys when the .dll file is detached. Additional query words: ====================================================================== Keywords : exc55sp3 kbExchange550preSP4fix kbExchange550sp4Fix kbgraphxlinkcritical Technology : kbExchangeSearch kbZNotKeyword2 kbExchange550SP3 Version : winnt:5.5 SP3 Issue type : kbbug Solution Type : kbfix ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.