DOCUMENT:Q222173  26-MAR-1999  [exchange]
TITLE   :XADM: Event ID 42, "The database engine found a bad page"
PRODUCT :Microsoft Exchange
PROD/VER:winnt:5.0
OPER/SYS:
KEYWORDS:

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The information in this article applies to:

 - Microsoft Exchange Server, version 5.0 
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SYMPTOMS
========

When you run Microsoft Exchange Server version 5.0, the server may receive the
following event in the Windows NT Application Log of Event Viewer:

Event ID: 42
Source: EDB
Type: Warning
Category: General
Description:
MSExchangeIS ((###) ) The database engine found a bad page.

This event indicates that the internal structure of the database has been
comprimised, as the database's internal references (pointers) are mis-aligned
and/or corrupted. The server may become unusually slow, sluggish, or
unresponsive.

CAUSE
=====

This can result from replaying the incorrect transaction log files after a
restore operation.

A JET_errBadPageLink error, or "bad page link," indicates logical corruption, not
physical corruption. For further information regarding physical corruption in an
Exchange Server Database, please refer to the following Microsoft Knowledge Base
article:

   Q151789 XADM: Error -1018 (JET_errReadVerifyFailure)

WORKAROUND
==========

To work around this problem, perform the following steps:

1. Restore the Exchange Server Database from most recent Full Online Backup:

    - Restore the Exchange Server Database from the most recent Full Online
      Backup BEFORE the Event ID 42 started appearing in the Application Log of
      Event Viewer. NOTE: It is crucial that only the log files that are
      restored from tape get replayed, NOT any existing log files that may exist
      on the Exchange Server's hard drive.

    - After that is done, the customer can use the Microsoft Exchange Mailbox
      Merge (exmerge.exe) utility to export the users' data, then import it back
      into a new priv.edb file. This utility is included in the Microsoft
      BackOffice Resource Kit version 3.0

2. Use the "Move Mailbox" feature in the Exchange Administrator program to move
   users from the corrupt Exchange Server to another. Recreate the priv.edb file
   on the original server, then move the users back to the original server.

   CAUTION: The next series of steps contain information about using the
   Microsoft Exchange Database utility (edbutil.exe). Using it incorrectly can
   cause catastrophic problems. Before you run this utility, you should first
   make a backup copy of the database files. Microsoft cannot guarantee that
   problems resulting from the use of the utility can be solved. Use this tool
   at your own risk.

3. Attempt to run EDBUTIL /D (Offline Defrag)

   This may remove the bad page link (if the bad page link resides in an unused
   portion of the database). Make sure you have a backup of the Exchange Server
   Database before you begin.

4. Attempt to run EDBUTIL /D /R (Repair)

    - This will forcefully remove the bad page link from the Exchange Server
      Database. Make sure you have a backup of the Exchange Server Database
      before you begin.

    - After EDBUTIL /D /R has finished successfully, try restarting the
      Information Store. If the Information Store starts, Microsoft highly
      recommends that Isinteg -fix be run against both the Private and Public
      Information Stores to resolve any inconsistencies that may have arisen as
      a result of running EDBUTIL /D /R.

      For additional information about Isinteg utility, please refer to the
      Troubleshooting section in Volume 2 of the Microsoft Exchange
      Administrator's Guide, or you can refer to Microsoft Knowledge Base
      article Q182081, "XADM: Description of ISINTEG Utility."

Additional query words: JET Corrupt Fix Hung Unresponsive

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Keywords          :  
Technology        : kbExchangeSearch kbExchange500 kbZNotKeyword2
Version           : winnt:5.0
Issue type        : kbinfo

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