Common Issues

Cause

By default, the Enable Circular Logging check box, located on the General tab of the Information Store object, is cleared. This means that Exchange 2000 does not delete the transaction log files of a storage group until a full backup of that Information Store is performed. This setting ensures that all messaging transactions are recorded in transaction log files, and that they are not deleted until they are saved on your backup media.

Caution   By default, circular logging is disabled. In most cases, you should keep circular logging disabled to increase your backup options and your ability to restore data. You should enable circular logging for a storage group only if that storage group contains non-critical data. If you enable circular logging, you can restore data only up to the last backup. You cannot restore data from the last backup to the point of the failure because the required log files are not available.

Solution

Enable circular logging for the storage groups that you do not need to back up.

To enable circular logging for a storage group:

1. Start System Manager
   On the Start menu, point to Programs, point to Microsoft Exchange, and then click System Manager.
2. In the console tree, double-click Servers.
3. Double-click the server containing the storage group for which you want to enable circular logging.
4. Right-click the storage group, and then click Properties.
5. On the General tab, click Enable circular logging, and then click Yes.

6. Important   Microsoft Product Support Services strongly recommends leaving circular logging disabled, because a full set of transaction logs greatly enhances your ability to recover Exchange.

For more information on backing up Information Store, see Microsoft Exchange 2000 Planning and Installation

Solution

Configure Exchange so that a specific set of users' mailboxes are located in a storage group with circular logging enabled. You must create a storage group, enable circular logging for that storage group, and then move the mailboxes that you want to place in that storage group.

Caution   By default, circular logging is disabled. In most cases, you should keep circular logging disabled to increase your backup options and your ability to restore data. You should enable circular logging for a storage group only if that storage group contains non-critical data. If you enable circular logging, you can restore data only up to the last backup. You cannot restore data from the last backup to the point of the failure because the required log files are not available.

To configure Exchange so that a specific set of users' mailboxes are located in storage groups with circular logging enabled:

1. From System Manager, create a storage group.

   Note   When creating the new storage group, on the General tab of the new storage group, click Enable circular logging, and then click Yes.

2. Important   Microsoft Product Support Services strongly recommends leaving circular disabled, because a full set of transaction logs greatly enhance your ability to recover Exchange.

3. From Active Directory Users and Computers, move the mailbox you want to the storage group with circular logging enabled.
4. Repeat step for 3 for each mailbox you want to move.

See also

Add a Storage Group