Using Database Circular Logging

Circular logging is enabled by default. Database circular logging uses transaction log technology but does not maintain all previous transaction log files. Instead, a few log files are maintained and eventually purged as new log files are created. Although circular logging helps manage disk space and prevents the buildup of transaction log files, you cannot perform differential and incremental backups because these backups rely on past transaction log files.

When database circular logging is enabled, you may see several Edbxxxxx.log files in the Mdbdata or Dsadata directories because Microsoft Exchange Server maintains a window of four log files for circular logging. However, if the server input/output (I/O) load is large, more than four log files will be used.

    To verify whether database circular logging settings are enabled follow this procedure

1. In the Administrator program, choose a server, and then select Configuration.
2. Select the server object within the Servers container.
3. From the File menu, choose Properties.
4. Select the Advanced tab.

Circular logging can be set separately for the information store and directory, and you can change these settings at any time by using the Administrator program. However, Microsoft Exchange Server will stop the corresponding service and restart it after making changes.