What is the best process to following when changing the circular logging setting on Databases within a DAG? We have 2 MB servers in the DAG. From what I can see, after the setting is changed, a dis-mount and re-mount is required for each Database. Should I simply dismount and remount them one by one, or is there a script that should be run first to eliminate downtime? Do I need to suspend the database copy first? Also, how can you confirm that the change took effect after the re-mount? When I tested disabling circular logging, the 'get-mailboxdatabase | fl command' showed that it was disabled immediately after unchecking the checkbox, even before re-mounting the database?DQ

Enabling/Disabling circular logging is directly related with backup with Exchange. mount/dismount is recommended to let IS service let inform for this changes immedeatly, But as you said it work without do it also. Exchange Circular Logging and VSS Backups: http://blogs.technet.com/b/exchange/archive/2010/08/18/3410672.aspxAnil MCC 2011,ITIL V3,MCSA 2003,MCTS 2010, My Blog : http://messagingschool.wordpress.com

Still not clear on this question: "How can you confirm that the change took effect after the re-mount? When I tested disabling circular logging, the 'get-mailboxdatabase | fl command' showed that it was disabled immediately after unchecking the checkbox, even before re-mounting the database?" If this command simply shows the setting in the gui, however a mount\dismount is required how can it be confirmed as active? Also, "Do I need to suspend the database copy first?" or just dismount and mount? Thanks, DQ

Hi, When you combine circular logging with continuous replication, you have a new type of circular logging called continuous replication circular logging (CRCL), which is different from ESE circular logging. Whereas ESE circular logging is performed and managed by the Microsoft Exchange Information Store service, CRCL is performed and managed by the Microsoft Exchange Replication Service. Specifically, the Microsoft Exchange Replication Service manages CRCL so that log continuity is maintained and logs are not deleted if they are still needed for replication. The Microsoft Exchange Replication Service and the Microsoft Exchange Information Store service communicate by using remote procedure calls (RPCs) regarding which log files can be deleted. Note: Circular logging must not be enabled for the specified mailbox database when you want to add database copy. So you may try to restart Microsoft Exchange replication services. Regards, Xiu

Hi, When you combine circular logging with continuous replication, you have a new type of circular logging called continuous replication circular logging (CRCL), which is different from ESE circular logging. Whereas ESE circular logging is performed and managed by the Microsoft Exchange Information Store service, CRCL is performed and managed by the Microsoft Exchange Replication Service. Specifically, the Microsoft Exchange Replication Service manages CRCL so that log continuity is maintained and logs are not deleted if they are still needed for replication. The Microsoft Exchange Replication Service and the Microsoft Exchange Information Store service communicate by using remote procedure calls (RPCs) regarding which log files can be deleted. Note: Circular logging must not be enabled for the specified mailbox database when you want to add database copy. So you may try to restart Microsoft Exchange replication services. Regards, Xiu Thanks for the reply Xiu, but I had read the Microsoft documents with the explanation. What I am looking for is the recommended (best practise) steps to follow when disabling circular logging in a production environment with 4 DB's and 4 copies in a DAG. I want to minimize downtime. This is required so that I can initiate incremental backups with our Symantec backup product. As an example of the answer I am looking for, note the following suggestions: : Disable circular logging and then reboot 1 DB server, once it comes up reboot the second? Or, : Stop the DB copy, disable circular logging, resume DB copy Or, : Run the startdagservermaintenance script, disable circular logging, run the stopdagservermaintenance script. DQ

Hi DQ, I don't think there is a best practice on this special scenario. In my opinion, you'd better disable circular logging for all DBs, and dismount\mount them one by one. And I think you don't have to stop the DB copy. The DB'S circular logging status is stored in AD with a name of msExchESEParamCicularLog, 1 for enable and 0 or disable. So no matter the active copy on which server, the status is always read from AD and related to DB, not the copies. In my test, I did what I said, nothing wrong. Hope it can help.Jack Zhou

Hi DQ, I don't think there is a best practice on this special scenario. In my opinion, you'd better disable circular logging for all DBs, and dismount\mount them one by one. And I think you don't have to stop the DB copy. The DB'S circular logging status is stored in AD with a name of msExchESEParamCicularLog, 1 for enable and 0 or disable. So no matter the active copy on which server, the status is always read from AD and related to DB, not the copies. In my test, I did what I said, nothing wrong. Hope it can help. Jack Zhou Thanks Jack, even though not directly listed step by step in any documentation that I could find, this is what I came up with as well. A second set of eyes always helps, and I'll give it a go. Thanks again, DarrellDQ