Using external backup and restore
An external backup or restore operation is performed external to Informix, without using ON-Bar or ontape during the backup or restore. The data is backed up or restored using a third-party tool instead.
Following are the high-level steps required to perform an external backup:
- Block the database server using
onmode -c block.
- Back up all the storage spaces and administrative files using a third-party tool or copy command.
- Unblock the database server using
onmode -c unblock.
- Back up all the logical logs, including the current log using
ontape -a(ontape) or
onbar -b -l -c(ON-Bar).
Following are the high-level steps required to perform an external restore:
- Salvage the logical logs using
ontape -S(ontape) or
onbar -b -l -s(ON-Bar).
- Restore all the storage spaces from an external backup to the original locations using a third-party tool or copy command.
- Perform an external restore of all storage spaces and logical logs using
ontape -p -efollowed by
ontape -l(using ontape) or
onbar -r -e(using ON-Bar).
You can perform an external backup of an RS secondary server. Performing a backup of an RS secondary server blocks that RS secondary server, but it will not block the primary server. You can perform a logical restore from the logs backed up from the primary instance. The backup obtained from the secondary server cannot be restored with level-1 or level-2 backups.
The external backup will not be complete if the database instance contains any of the following:
- Non-logging smart large objects
- Regular blobspaces
- Non-logging databases
- Raw tables
If an external backup is performed on an instance that contains any of the above items, the backup will be incomplete and cannot be used to restore the primary server.
Table 17 shows configuration parameters that are important to perform external backup on an RS secondary server.
Table 17. Configuration parameters for external backup on RS
|STOP_APPLY||Stops the application of the logical log files on the RS secondary server. It might not be set on a RS secondary server before an external backup, because it will be set by the external backup itself.|
|LOG_STAGING_DIR||Defines where logical logs from the primary will be stored while using STOP_APPLY.|
After the archive checkpoint is processed, the RS secondary server stops applying logical logs, but it continues receiving logs from the primary server. The primary database server must be online or in quiescent mode during an external backup.
To perform the external backup on RSS, follow the same steps described for the external backup.
Logical log backup is possible only on the primary server.