Event ID 9840 or 9607 is logged when a VSS backup operation fails in Exchange 2007 or in Exchange 2003

When you try to perform a Volume Shadow Copy Service (VSS) backup of a mailbox database or of a public folder database in Microsoft Exchange Server 2007, the backup operation fails. Additionally, one of the following events is logged in the system event log:

Event ID : 9840
Raw Event ID : 9840
Record Nr. : 50522
Category : General
Source : MSExchangeIS
Type : Error
Generated : 12/8/2006 7:06:14 AM
Written : 12/8/2006 7:06:14 AM
Machine : MachineName
Message : An attempt to prepare the storage group 'sg2' for backup failed because the storage group is already in the process of being backed up. The error code is -2403. (Note that if a backup was recently aborted, then it may take several minutes for the system to detect the aborted backup and initiate backup cleanup procedures, so this message may be generated if an attempt was made to backup a storage group before a previous backup attempt had fully terminated.)

Event Type: Error
Event Source: MSExchangeIS
Event Category: General
Event ID: 9840
Date: 11/9/2006
Time: 5:44:53 PM
User: N/A
Computer: ComputerName
Description: An attempt to prepare the storage group 'sg3' for backup failed because the storage group is already in the process of being backed up. The error code is 1293. (Note that if a backup was recently aborted, then it may take several minutes for the system to detect the aborted backup and initiate backup cleanup procedures, so this message may be generated if an attempt was made to backup a storage group before a previous backup attempt had fully terminated.)

When you try to perform a VSS backup of a mailbox database or of a public folder database in Microsoft Exchange Server 2003, the backup operation fails. Additionally, the following event is logged in the event log:

Event Type: Error
Event Source: MSExchangeIS
Event Category: Exchange VSS Writer
Event ID: 9607
Date: 6/15/2007
Time: 9:30:06 PM
User: N/A
Computer: ComputerName
Description: Error code 0x50d when preparing for backup. For more information, click http://www.microsoft.com/contentredirect.asp.
Data: 0000: 42 61 63 6b 75 70 20 69 Backup i 0008: 6e 20 70 72 6f 67 72 65 n progre 0010: 73 73 2e 00 ss..

This problem may occur if the following conditions are true:

• VSS uses the Microsoft Jet database engine to freeze or thaw a snapshot backup.
• The Jet database engine encounters an error.
• The Jet database engine silently frees all storage groups from the snapshot session when the error occurs.

When these conditions are true, the Jet database engine does not report the correct status of these storage groups to Exchange 2007 or Exchange 2003. Therefore, Exchange does not reset the backup-in-progress state. If you try to back up the affected storage group again, the symptoms that are described in the "Symptoms" section occur.

To resolve this problem, use one of the following methods, as appropriate for your situation.

Method 1: Dismount all databases in the storage group

Use this method if the event ID 9840 that was logged on the Exchange 2007 server contained error code 2403.

To dismount all databases in the storage group, follow these steps:

1. Click Start, point to All Programs, point to Exchange Server 2007, and then click Exchange Management Console.
2. Expand Server Configuration, and then expand the storage group that is listed in the event ID 9840 message that was logged on the Exchange 2007 server.
3. Right-click each database in that storage group, and then click Dismount Database.
4. Click Yes to confirm the operation.
5. After the dismount operation is complete, right-click the database again, and then click Mount Database.
6. Try to perform the backup operation that resulted in event ID 9840.

If this method does not resolve the problem, try method 2.

Method 2: Restart the Microsoft Exchange Information Store service

Use this method if the event ID 9840 that was logged on the Exchange 2007 server contained error code 1293. Use this method if Event ID 9607 was logged on Exchange 2003. Additionally, use this method if method 1 did not resolve the problem.

To restart the Microsoft Exchange Information Store service, follow these steps:

1. Click Start, point to All Programs, point to Administrative Tools, and then click Services.
2. Right-click Microsoft Exchange Information Store, and then click Restart.
3. Try to perform the backup operation that resulted in event ID 9840.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.