How to Manually Move Exchange Logs to Clear Enough Storage Space to Mount EDBs and Force a Successful Log Truncation Snapshot
If Rapid Recovery is enabled to perform automatic log truncation with the nightly jobs and it fails to do so, your Exchange server’s log directory might begin to fill up. When this storage location becomes full Exchange is no longer able to process new mail flow and the Exchange application will be brought down. This will more than likely have huge impacts with routine business operations. Due diligence needs to be practiced in order to avoid the above scenario, such as setting up email alerts that the Exchange Log Truncation snapshot failed or monitoring your deployed systems.
If the above situation has happened in which the transaction log storage volume is full, then the Exchange databases are more than likely not mounting. If the EDBs are not mounted, then Rapid Recovery cannot successfully do a log truncation snapshot. The Rapid Recovery Core will state that the log truncation snapshot transfer job was successful, but the Application Event logs on the protected Exchange server will detail otherwise.
Exchange transaction log truncation will not happen normally because the backup software has stopped functioning normally. This can be due to configuration settings within Rapid Recovery or issues with the VSS subsystem on the protected Exchange server (for example, a missing or failed Exchange VSS writer).
The following steps require that the Exchange databases are not mounted and that an understanding of where the EDB and transaction log file locations are located. It will require the use of eseutil and a temporary storage location that can accommodate the size of the transaction log files that are being moved. If your Exchange databases are unmounted and this is caused because your transaction logs have filled up your storage location (and with no other means of being able to expand the storage of volume, such as within a VM), proceed with the following steps:
1. Open a cmd prompt as Administrator
2. Execute the cmd eseutil /MH “Path to Exchange Database file.EDB”
3. Verify the “State” of the EDB. This will either be “Clean Shutdown,” “Dirty Shutdown,” or “Inconsistent.”
4. For “Clean Shutdown” State, you can copy all transaction logs except the latest and current transaction log file. The recommendation would be to leave a good chunk with a recent time stamp available and move all other older files temporarily off to your temp storage location.
5. For “Dirty Shutdown” or “Inconsistent” State, verify the “Log Required” section of the eseutil /mh output. This hex name is consistent with any current transaction log files located in your log storage location. You can temporarily move the logs OLDER THAN this required log file.
6. DO NOT delete any log files that you temporarily moved until you have comfortably performed a complete full backup of the storage group.
7. Once the log files have been moved, attempt to mount the EDB. If this proves successful, you can test the flow of mail through Exchange.
8. In Rapid Recovery, perform a Force Log Truncation of the Exchange database and monitor the backup job to ensure that the transaction logs have been truncated.