DOCUMENT:Q186184  12-APR-1999  [exchange]
TITLE   :XADM: Cannot Perform Online Backup After Repairing Database
PRODUCT :Microsoft Exchange
PROD/VER:WINDOWS:5.5
OPER/SYS:
KEYWORDS:

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The information in this article applies to:

 - Microsoft Exchange Server, version 5.5 
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SYMPTOMS
========

After you use the Eseutil.exe program with the /P switch to repair a Microsoft
Exchange Server database, you may be unable to perform an online backup of the
database until you defragment it.

CAUSE
=====

When you use the Eseutil.exe program to repair an Exchange Server database, a
-1018 error (JET_errReadVerifyFailure) may be returned when a checksum test is
performed on a page in the database. When this occurs, Eseutil.exe corrects the
problem by preventing the page from being used, but it does not reset or delete
the page. Because the online backup program reads every page in the database,
the invalid page is still read when an online backup is performed.

WORKAROUND
==========

To work around this problem, use Eseutil.exe with the /D switch to defragment
the database. This removes the invalid pages from the database, allowing an
online backup of the database to be performed.

STATUS
======

Microsoft has confirmed this to be a problem in Microsoft Exchange Server
version 5.5. This problem has been corrected in the latest U.S. service pack for
Microsoft Exchange Server version 5.5. For information on obtaining the service
pack, query on the following word in the Microsoft Knowledge Base (without the
spaces):

   S E R V P A C K


MORE INFORMATION
================

When you use Eseutil.exe to defragment a database, all the data in the database
is copied to a new file. During this process, Eseutil.exe does not read pages
that are not being used. Therefore, all unused pages are removed from the
database, including any invalid pages that Eseutil.exe previously encountered
while it was repairing the database.

The online backup program is the only program that reads unused pages. The pages
are not read when the database is online or when an offline repair or
defragmentation is performed. In addition, because the pages are unused, no data
is affected by the fact that the pages are invalid.

When you use the Eseutil.exe program to repair an Exchange Server database after
you apply the fix, Eseutil.exe resets any invalid pages that it finds. This
allows an online backup to be performed before the database is defragmented.

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Keywords          :  
Technology        : kbExchangeSearch kbExchange550 kbZNotKeyword2
Version           : WINDOWS:5.5
Issue type        : kbbug
Solution Type     : kbfix

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