Forum Discussion

RajkumarBaniwal's avatar
11 years ago

Oracle DB backups using excess media


Whenever Oracle RMAN backup runs, its child jobs uses media and when its parent job fails, we have to restart the backup as that backup is corrupted (I think, because its parent job failed)

So when ever RMAN parent job fails, we are restarting the backup. My query is how to recover media space which was occupied by that child jobs. Is it only solution to expire that images? or something else?

Master server: Netbackup (Solaris)

Db server (Solaris )Oracle 10.

7 Replies

  • Hi, Thanks for reply, but i m  not asking cleanup images/ expiring media.

    My query is suppose I have a DB client name ars01 and its db full backup started by allocating 4 channels in rman script( now in activity monitor i can see 1 parent job and 4 child job running), Now my all child jobs completed but parent job failed with error. That backup will be inconsistent and is of no use as per DB team.

    Now my question is that these 4 child jobs which occupies some media space is having 1 month retention. Is netbackup automaticaly expires the child job data immediately after failing of parent job or we need to expire it manually to get back that space.

  • Netbackup will not release the space used if it's on tape. Tape is a sequential media, not random access. The entire tape has to expire before the space can be re-used.  If they are disk based they will be released with 12 hours as Wr mentioned.

    My recommendation is to accept the fact that you loose tape space due to failed backup from time to time. If you start expiring backup there is a risk you expire the wrong image and you use more time performing this task than a new tape cost.

    Best Regards


  • I don't generally look at DB backups, but from a general viewpoint ... If you have a backup running to tape (let's say single stream, not mpx) and it fails, NBU will reposition to just before the start of the failed backup and write the 'logical-end-of-data' at that point. Therefore, the next use of that tape will overwrite the failed backup. If a backup is successful, and is then expired later, as explained by Nicolai, the space is not released until everything on the tape expires.
  • Hi Nicolai,


    Is there any way to configure netbackup to expire the images of that child job backup?

  • You can set the backup pieces larget than all the data files.

        TAG hot_db_bk_level0
        FILESPERSET 5   # FILESPERSET big enough!!!
        # recommended format
        FORMAT 'bk_%s_%p_%t'
        sql 'alter system archive log current';