Overview of backup to disk, cloning, retention and restore
The retention process consists of:
- Clone the backup to clone the device (if specified in the disc mediapool definition).
- Delete the backups if they are older than the retention time and if they are cloned (if the cloning was defined).
The client knows nothing about cloning (or about the existence of backups in their original device), backup server knows about its existence and it logs all cloning processes in Hiback \ log \ svc.log.
The clone target may be the type disc, tape (single tape) or al (autoloader) and can be located on the local or remote backup server.
If a client wants a restore from the backup server, it will ask for the disc backup (ie the original backup). The requested one consists of a disc device name, a backup ID and the restore file set.
The backup server then searches for the disc device directory (for example, E: \ disc.0001) for the backup.
If he finds it, the restore will be directly satisfied.
If the backup server does not find the requested disc backup on the client, it looks in Hiback \ log \ svc.log to see if there is one more clone left for this backup.
If there is access to this backup in Hiback \ log \ svc.log, the backup server works with this information (clone server name, clone device name), sends it back to the client and says "Goodbye".
The backup client now knows that it takes a few seconds to start up and contact the clone server for the requested restore. The clone server works like the backup server; it looks like he could retrieve the request from the given device and if it is not possible he will look in hiback \ log \ svc.log to look for clones.
This procedure works for clones up to 2nd degree (backup -> clone (backup) -> clone) and is invisible to the user.