How to disable circular logging in Microsoft Exchange so that differential or incremental backups of Exchange Storage Groups and Databases can be performed.
Problem
How to disable circular logging in Microsoft Exchange so that differential or incremental backups of Exchange Storage Groups and Databases can be performed.
Error Message
Job Log shows :
V-79-57344-33943 - AOFO: Initialization failure on: "Microsoft Information Store". Advance Open File Option used: Microsoft Volume Shadow Copy Service (VSS).
Snapshot provider error 0xe0008497 - Incremental and differential backups are not possible because Microsoft Exchange is configured for circular logging.
Cause
The above error is encountered when :
- Circular Logging is enabled for Exchange Database.
- Microsoft information Store Service was not restarted.
- Exchange Database was not dismounted and remounted after disabling Circular Logging.
Solution
When circular logging is enabled, transaction log files that have already been committed to the database are overwritten, preventing the accumulation of logs. The log files are overwritten whether or not a full or incremental backup has been run, and a history of previous logs since the last full or incremental backup is not maintained. This is why, when circular logging is enabled, differential and incremental backups of the Exchange databases cannot be performed (since these types of backups rely on complete history of logs).
Note: Exchange Server supports multiple databases and storage groups on the same server. Each storage group is controlled by a separate instance of the Extensible Storage Engine (ESE). Therefore, each storage group shares the same set of log files. As a result, circular logging is enabled or disabled for a particular storage group, not for a particular database.
Circular logging and disk space:
When circular logging is disabled, transaction log files accumulate on the disk until a full or incremental backup is performed. After this, the log files that have all transactions committed to the database are deleted. Performing a full backup of the Microsoft Exchange Server is the preferred way of saving the log files and removing these logs from the disk to utilize the space effectively. If a solid backup strategy is in place, transactions log files are purged during the backup, which frees disk space.
How to Disable Circular Logging in Exchange 2007 :
- To use the Exchange Management Console to disable circular logging:
- To disable circular logging using Exchange Management Shell, run the following command:
- To use the Exchange Management Console to disable circular logging:
- To disable circular logging using Exchange Management Shell, run the following command:
Microsoft article: technet.microsoft.com/en-us/library/dd297937.aspx#UseShell & technet.microsoft.com/en-us/library/bb123971.aspx
- To use the Exchange Admin Center (EAC) to disable circular logging:
- To disable circular logging using Exchange Management Shell, run the following command:
Microsoft article: technet.microsoft.com/en-us/library/dn756374(v=exchg.150).aspx
Note: The information store service must be restarted because when it starts, it reads configuration information from the Active Directory. The Active Directory attribute associated with the circular logging setting is called MSExchESEParamCircularLog. When circular logging is enabled, this attribute is set to 1. When circular logging is disabled, it is set to 0.
Applies To
Microsoft Exchange 2007.
Microsoft Exchange 2010.
Microsoft Exchange 2013.