If you turn on circular logging while the stores are dismounted, will the logs be purged, (Deleted) or will they remain on the drive and be ignored by Exchange?Thanks.Martin.Martin

My reckoning is that it wont be applied until the MS Exchange Information Store has been restarted and the DB has been mounted. Else the change wont be applied and the DB wont be mounted to be acted upon... So yes they would remain on the drive.

Sorry I'm a bit unclear.Will the logs be purged when the stores are mounted?Martin

Even if you enable the circular logging while the store is dismounted the previous logs which were generated will not get purged & also even after mounting the store these old logs will still remain so before you mount the store move these old logs to a temp folder & then mount the store.New logs will automatically get purged after mounting the store in the storage group.Best Practice is to run the Backup of the Exchange Databases so the logs are automatically purged from the storage location.Aslam Surve