Source:Troubleshooting MS Exchange
Microsoft Exchange Server
Exchange backup fails with VSS API error due to missing Microsoft Exchange VSS writer
Problem
When backing up Exchange, the backup fails because the Microsoft Exchange VSS writer required for backup is missing. The following error occurs:
sbc-1178: Error: VSS API error: CVssServer::CreateSnapshot: No volume could be determined. sbc-1146: Error: DB Module: [BackupProcessing: For the specified backup source no volumes could be determined. Sources - \Microsoft Exchange Writer] sbc-3052: Info: Items processed correctly: [0]. Not processed or incorrectly processed items: [0]. (SF20160503083743700@BLljg0gnWAa) sbc-1156: Error: Operation failed! sbc-3001: Info: Exiting.
This error occurs when one or more writers required for backup are missing or not available. Note that this is not the same as VSS error or failed VSS. In the latter case, check Common VSS problems.
A writer is consider missing, if running (as administrator) the Microsoft command-line tool vssadmin list writers shows no available Microsoft Exchange VSS writer. If a VSS writer is missing, all backups that use that writer to perform VSS snapshots will fail. A missing writer is a failure of the Windows operating system. To fix this issue, Windows registry needs to be edited. SEP sesam cannot back up any data until the required VSS writers are available.
Solution
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Note |
| SEP sesam is not responsible for any issue caused by Windows registry editing. Note that only experts should edit the registry, as using Windows registry editor incorrectly can cause serious problems, such as Windows to stop working. For more information on editing Windows registry, see Windows registry information for advanced users. It is advised to back up the registry before making any change to it. It is also recommended to perform the following procedure outside of working hours as it requires restarting the Microsoft Exchange Information Store service. |
To enable Microsoft Exchange VSS writer, on the Exchange server open and edit the registry with the following key value:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersSystem\ "Disable Exchange Writer" DWORD=0
If the key already exists with a value of 1, change the value to 0. (Value 1 disables the Microsoft Exchange Writer.) For more information on enabling VSS Exchange writer, refer to How to turn on the Exchange writer for the Volume Shadow Copy service (it is marked as relevant for Windows Small Business Server 2003, but the procedure can also be applied to later versions).
Then restart the Microsoft Exchange Information Store service:
- Log in to the Exchange server and click Start.
- Enter services.msc in the search box, and press Enter. The Services window opens.
- From the list of services, right-click the Microsoft Exchange Information Store service (MSExchangeIS), and then click Restart. Note that during restart the users will be disconnected from Exchange.
After restarting Exchange, in the command prompt enter vssadmin list writers and verify that the VSS writers are listed. Then run your Exchange backup again.
Exchange logs truncation errors
Problem
The Exchange logs are not truncated or the log files are missing.
Cause
Exchange database log truncation is part of Exchange services. SEP sesam notifies Exchange Writer of each successful backup of Exchange Server and Exchange DAG nodes. SEP sesam does not manage or delete Exchange logs and is therefore not responsible for truncating logs, Microsoft Exchange Writer is. SEP sesam only notifies Exchange of the backup status and then:
- In configurations without DAG, Exchange Writer truncates the transaction log files after a successful full or incremental backup.
- In DAG replicated configurations, log truncation is delayed by the replication service until all required log files have been replayed into all other copies. The replication service deletes the backed-up log files from both the active and the copy log file paths after verifying that the log files have been successfully applied to the copy database and that both the active database and the database copies checkpoint have passed the log files to be deleted.
⇒ Solution
To verify that Exchange log truncation has been called, check the Applications and Services Logs and look for errors related to the Exchange VSS or Replica writer.
Check ESE events with ID:
- 224: This event indicates that logs are being deleted and denotes the associated database.
- 225: This event indicates that there are no logs available for truncation (either ESE cannot determine whether the transaction log files have been committed to the Exchange Server database, there are not enough logs or Circular Logging is enabled).
- 299: The replication service truncates the log stream and removes transaction logs that are no longer needed (or reports that there is not a minimum amount of logs for truncation).
If the Exchange configuration uses DAG, the replication process between the different nodes can prevent log truncation in case of errors. These errors are indicated with the event source MSExchangeRepl.
Below are some entries from the application log in the Event Viewer (for a list of errors, see the Microsoft article MSExchangeRepl Errors and Events):
· Event ID 224 (ESE) MDB01 deleting log files C:\ExchVols\MDB01\Log Files\E0000000001.log to C:\ExchVols\MDB01\Log Files\E000000002B.log. · Event ID 225 (ESE) MDB01—no log files can be truncated; will be logged instead of Event ID 224 when circular logging is used. · Event ID 2046 (MSExchangeRepl) VSS writer has successfully completed the backup of database MDB01. · Event ID 2006 (ESE) MDB01 shadow copy completed successfully. · Event ID 2033 (MSExchangeRepl) VSS writer has successfully processed the backup completion event. · Event ID 2037 (MSExchangeRepl) VSS writer backup has been successfully shut down.
If errors occur in connection with the Exchange VSS or Replica Writer, check the Exchange configuration to determine the cause and resolve the errors. Such errors cannot be caused by SEP sesam, but until they are resolved, Exchange cannot truncate the log files, resulting in filling up the volume or disk where they reside.
Also check the current status of the VSS writer by running the following at an administrative prompt on the Exchange server:
vssadmin list writers
If the writer is missing or is in a failed state, reboot the Exchange server and verify that it is now listed and showing as stable. Then restart the SEP sesam Exchange backup task and check the log truncation.
Exchange Recovery Pro asks for License
If you have started Exchange Recovery Pro the first time you get prompted to install the license. If you use several different Windows users, you get this prompt for every user.