3 Replies Latest reply: Feb 11, 2013 6:56 PM by rdoogan-Oracle RSS

    Help determining OSB media family settings


      I'm quite new to OSB, and a client has asked for the following:

      1. Backup a single dataset nightly. Just filesystems no RMAN.
      2. 3 nightly backups per volume
      3. 1 volume gets removed from the library at the end of the month, it being the most recently written volume. Off-site tapes are locked up and never returned to the library.
      4. Use new tapes when available, otherwise reuse whichever is the oldest volume in the library.
      5. Tapes will be restocked whenever they get low (starting with 29 tapes in the library).

      I'm pretty sure this is not possible in it's entirety with OSB, but I have only limited experience with it. I will try to get as close as possible, however.

      My current thoughts to meet this are:

      1. Backup nightly to a time-managed media family with a write window of 3 days.
      2. Manually remove the most recent tape from the library with an "extract volume" command on whatever is the most recently written volume.
      3. Set the retention time on the media family so that each tape can be reused 7 days after it's write window closes. This will mean that we can get down to 3 remaining tapes before having to restock. As recycled tapes are used before new tapes it also means that volumes will be kept for no more than 7 days, however, so requirement point 4 is not met.

      I'm pretty sure vaulting is not going to help me get closer to the requirements here, but I hope to be corrected.

      Is there any way to override the "Use expired tapes first" behaviour of OSB so it uses new tapes where possible? Anything else obvious that I've missed here?

      Thanks in advance,

        • 1. Re: Help determining OSB media family settings
          I think you want to consider using tape duplication and then vaulting the duplicated tape, that way you can easily set the forever expiration on the duplicated volume while keeping the tapes in the library for fast restores. Using that with vaulting also ensures that OSB knows exactly where your tapes are, and their expire dates.


          • 2. Re: Help determining OSB media family settings

            Probably another naive question, but duplication requires 2 drives correct? We only have one in our library at the moment.

            I could also make another media family and just run the backup twice (once to each family) on the last day of the month -- it's not a big backup and can complete quickly.

            However, neither of these address the problem (in my client's eyes) of the expired backups being overwritten in preference to using fresh tapes.

            • 3. Re: Help determining OSB media family settings
              Right, yes, you would need two drives to do a duplication.

              If a tape's expired there is no problem with overwriting it for new backups, so what is the concern here?