RESTARTABLE_RESTORE configuration parameter
Use the RESTARTABLE_RESTORE configuration parameter to control whether the database server performs restartable restores.
- onconfig.std value
- RESTARTABLE_RESTORE ON
- values
ON
= Restartable restore is enabledOFF
= Restartable restore is disabled- takes effect
- After you edit your onconfig file and restart the database server.
If you set RESTARTABLE_RESTORE to ON
,
you enable the database server to restart a failed physical or cold
logical restore at the point at which the failure occurred. To perform
a restartable restore with ON-Bar,
use the onbar -RESTART command.
Increase
the size of your physical log if you plan to use restartable restore.
Although a restartable restore slows down the logical restore if many
logs need to be restored, you save a lot of time from not having to
repeat the entire restore.
Important: If the database server
fails during a warm logical restore, you must repeat the entire restore.
If the database server is still running, use onbar -r -l to
complete the restore.
If you do a cold restore on systems that are not identical, you can assign new pathnames to chunks, and you can rename devices for critical chunks during the restore. You must perform a level-0 archive after the rename and restore operation completes.
The database server uses physical recovery and logical
recovery to restore data as follows:
- Physical recovery. The database server writes data pages from the backup media to disk. This action leaves the storage spaces consistent to the point at which it was originally backed up. However, the backup times for each storage space are usually different. A restartable restore is restartable to the level of a storage space. If only some chunks of a storage space are restored when the restore fails, the entire storage space needs to be recovered again when you restart the restore.
- Logical recovery. The database server replays logical-log records on media to bring all the storage spaces up to date. At the end of logical recovery, all storage spaces are consistent to the same point.