Autorecovery is a special feature for Backup tools not supporting vss restore. Instead of a vss restore these tools will perform a bare metal or Virtual Machine recovery. In this cases the Windows VSS Service will never be informed that a restore has been performed and the writer cannot prepare the database.
To enable a point-in-time recovery in this scenario the database has to be set in valid recovery state. This is done by autorecovery:
When the database host is started after a restore the VSS Writer will detect this by a flag stored in the snapshot. Then the database will be automatically set into the recovery state.
Please be aware that you may have to apply log files manually before you can start the database again. If any automatic startup procedure opens the database no more log files can be applied.
If you use startup scripts to start SAP or the database automatically after reboot, you should update them to make sure that they are not executed if the database is allready in admin state.
Simple Log Management¶
The simple log management features allows to include log files into the database backups and to delete log files after sucessfull backups.
To use log management your log backup media has to be defined as file backup. The target folder should to be on a disk that is included in the backup. It is recommended to use a separate disk to store log backups, because you can recover it as a complete volume from a second backup. With a separate disk you can also schedule additional log backups that only contain the log data.
Please be aware that the log files are not restored automatically, you have to restore them manually using the second backup. For recovery you can than use the MaxDb command line or the database studio.
Log Backup before Snapshot¶
To achieve this the log files can be writter out of the database to a local volume before the VSS snapshot is taken. Then the backup will contain the current state and the required log files to restore at a point between this backup and a previous backup.
This feature is activated with the option “backupBeforeSnapshot”.
Log Backup after database backup¶
It is also possible to execute log backup automatically after to database backup. This is useful if you would like to create backups for SAP system maintainance without using the MaxDb backup tools. The reason for this is that the SAP tools are checking for both a database and a log backup.
Do not use this feature, if you have the ability to select the database component logs in your backup tool. Instead create and use a backup definition for log backups only.
This feature is activated with the option “backupOnBackupComplete”.
Logs can also be deleted after a sucessfull VSS backup. Log truncation will only consider files stored on local filesystem.
This feature is activated with the option “truncateOnBackupComplete”.