XADM: Open File Backup Backs Up Inconsistent Exchange Databases

• Microsoft Exchange Server, versions 4.0, 5.0, 5.5

SYMPTOMS

If you use backup software that performs a backup of the Exchange Server database files while the Exchange services are running, the backup of the databases will be inconsistent. If you restore this backup and attempt to start the respective Exchange Server services, you will receive the following error message on the screen, in the Windows NT Event Viewer Application log, or both:

   Error -550 has occurred

CAUSE

The Exchange databases are a combination of the database files (.Edb files) and the logs (.Log files). All transactions occurring in Exchange Server are written to the log files first and then written into the actual database files, after a period of time.

The Exchange databases are considered to be consistent when all transactions from the log files have been written into the database files. The database is then consistent with the log files. When the information store service is shut down, all transactions from the log files are written into the information store service databases (Priv.edb and Pub.edb). When the directory service is shut down, all transactions from the log files are written into the directory database (Dir.edb). The only time you can be absolutely certain that an Exchange Server database is consistent is when its respective service is shut down without error.

WORKAROUND

To work around this problem, do one of the following:

- Use backup software that is designed to back up Exchange Server while it

   is online.

- Stop the information store and directory services before you perform a

   backup of the Exchange Server databases.