XADM: Backup Stops with Event ID 105 and Error 1808 (271847)


The information in this article applies to:

  • Microsoft Exchange Server 5.5
This article was previously published under Q271847

SYMPTOMS

When you back up Exchange Server 5.5 on a computer that is running Windows NT 4.0 Service Pack 3, the Windows NT backup may stop, and the following event may appear in the application log of Event Viewer:
Event ID 105
Source:ESE97
Type:Error
Category:Logging/Recovery
Description:MSExchangeIS ((367) ) The database engine has stopped the backup with error -1808.
The error -1808 is 0xFFFFF8F0 JET_errDiskFull
No space left on disk 4294965488

CAUSE

This behavior can occur if the .pat (patch) files fill the remaining disk space during the backup.

RESOLUTION

To resolve this behavior, add an additional hard disk to gain the extra space required for backups, and then following these steps:
  1. Run the Eseutil utility with the /d switch to defragment the information store and directory databases.

    NOTE: This requires space equal to 110 percent of the size of the database.
  2. Reduce the size of the backup by moving some mailboxes to another server.
  3. Set mailbox size limits in the information store.

MORE INFORMATION

During an online Exchange Server backup, transactions can be entered for .edb files. If a transaction occurs for a part of the .edb file that has not yet been backed up, it is simply processed. If a transaction occurs for a part of the .edb file that is already backed up, the transaction is recorded in a .pat (patch) file.

Patch files consist of an 8-kilobyte (KB) (8,192 byte) header plus 4-KB database pages. A separate .pat file is used for each database: Priv.pat, Pub.pat, and Dir.pat. These files are temporary files that are created during the backup process.
Here is how .pat files fit into the online backup sequence:
  • A .pat file is created for the current database.
  • The backup for the current .edb file begins.
  • Transactions that must be written to parts of the .edb file that have already been backed up are recorded to the .edb and .pat files.
  • A .pat file is written to the backup tape.
  • The .pat file is deleted from \MDBDATA and \DSADATA.
For additional information, click the article number below to view the article in the Microsoft Knowledge Base:

158526 XADM: .Pat Files in Mdbdata and Dsadata Directories

Modification Type:MinorLast Reviewed:4/21/2005
Keywords:kbenv kbprb KB271847
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