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manatee's avatar
manatee
Level 6
11 years ago

recycling tapes

NBU 7.5.0.5 master/media server

one year on since our NBU was installed, i noticed that backup images span multiple tape cartridges. now comes the hard part, how to recycle those cartridges when some images on a cartridge are expired while some are not yet expired?

do i keep buying new cartridges? or should we shift to a different backup strategy that doesn't use tapes?

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  • mph999's avatar
    mph999
    11 years ago

    You can't recycle tapes until all the images have expired.  Short of copying the non expired images to new media you will have to wait.

    You need sufficient cartridges to hold the images + new until old tapes expire, which, providing you do not allow mixed retention periods on a media, will be 1 year after the last image is written (if the retention period of all the images on the tape is 1 year)

    Allowing mixed retention periods is possible, but no recommended.  You may for example have a tape full of 1 month retention images, but also a single 1 year retention backup which should really have gone on a 1 years retention period only tape.  In other words, mixed retention periods use more tapes.

    Disk does not have this issue - however a report I read stated on average, more data is lost to disk failure than tape ... worth bearing in mind ...

     

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  • mph999's avatar
    mph999
    Level 6
    11 years ago

    You can't recycle tapes until all the images have expired.  Short of copying the non expired images to new media you will have to wait.

    You need sufficient cartridges to hold the images + new until old tapes expire, which, providing you do not allow mixed retention periods on a media, will be 1 year after the last image is written (if the retention period of all the images on the tape is 1 year)

    Allowing mixed retention periods is possible, but no recommended.  You may for example have a tape full of 1 month retention images, but also a single 1 year retention backup which should really have gone on a 1 years retention period only tape.  In other words, mixed retention periods use more tapes.

    Disk does not have this issue - however a report I read stated on average, more data is lost to disk failure than tape ... worth bearing in mind ...

     

  • manatee's avatar
    manatee
    Level 6
    11 years ago

    but how to configure NOT to use mixed retention periods for a single media? i think this is where my problem is.

  • manatee's avatar
    manatee
    Level 6
    11 years ago

    ok i checked properties of master server media and the mixed retention is not set. however, when i tried this command,

    ./bpimmedia -mediaid DAT002 -U|more

    i found on a single tape there are more than backup image with different expiry dates but same retention levels.

    therefore i cannot reuse such media because of different expiration dates.

  • mph999's avatar
    mph999
    Level 6
    11 years ago

    Yes.

    Of course, if backups are taken at different times, if all have the same retention period, the expiration times will be different.

  • Nicolai's avatar
    Nicolai
    Moderator
    11 years ago

    If the tape was filled in one night, it would expire all images at the same day.

    However if the retention is used rarely, it may take weeks to fill and the expiration will so to mentioned take "weeks". Basically you are only "allowed" to count toward expiration when the last backup image is written - not the fist.