Resolution

This issue occurs when a storage group exceeds 5,000 uncommitted Extensible Storage Engine (ESE) transaction log files. Each storage group has a hard-coded limit of 5,120 uncommitted ESE transaction log files. When the number of uncommitted ESE transaction log files in an ESE storage group reaches 5,000, Exchange 2007 attempts to automatically dismount the all databases in the storage group. Additionally, event ID 1159 is logged in the application log.

Uncommitted ESE transaction log files may be created in the following scenarios:

• A process is blocked in the backup software that you are using.
  
  
• The backup software that you are using is not responding.
  
  
• You are attempting to move many mailboxes during the same time that a backup process is scheduled to occur.
  
  
• The server is experiencing performance issues. For example, disk subsystem issues are preventing the server from responding quickly to simultaneous disk-intensive operations.
  
  

To resolve this issue, restart the Microsoft Exchange Store Information service. For detailed instructions, see How to Restart the Microsoft Exchange Store Information Service.