Forum Discussion

Serge_PARISET's avatar
Serge_PARISET
Level 2
7 years ago

Changing Retention levels on Tape

Hello,  I changed the retention level of all the images present  on a tape from one year to 2 years, this changes the data expiration time on the tape but the Retention level is still the old retent...
7.6
Solaris
  • mph999's avatar
    mph999
    7 years ago

    You cannot change the retention level once written.  You can only change the expire time.

    The retention level is written in the backup header on the tape, hence it cannot be changed

     

  • mph999's avatar
    mph999
    7 years ago

    The retention level doesn't really matter, once the exire time has been changed by bpexpdate.

    The time it would matter, is if the images were expired, and then imported - the expire time would revert back to the time set for the level number, relative to when the import was run.

    Do not ever mix retentions on tapes, short term it may help, long term you will use a lot more media.

    What you could do is reduce the number of partially full media for the volume pools to the same number, as the number of consecutive write drives in the storage unit(s).  For example, if you had 5 drives, set this value to 5 (in the volume pool) - this means that no more than 5 tapes are ever allowed to be partially full, meaning that you would have to fill a tape before another could be used.  Having 5, means that all tape drives can be used at once.

    It is not 100% guaranteed, there are times you may use a few more tapes than 5, but it should reduce the number of tapes used on average.

Tousif's avatar
Tousif
Level 6
7 years ago

Hello,

 

I don't think  you can change the retention level. May I know, why you are trying to change retention level?

 

Thanks & Regards,

  • Serge_PARISET's avatar
    Serge_PARISET
    Level 2
    7 years ago

    Hello Tousif, 

    Customer just changed  monthly retention from one to two years, and I was wondering how to consume less tapes, because we do not mix retention on tapes.

    regards.

    • mph999's avatar
      mph999
      Level 6
      7 years ago

      The retention level doesn't really matter, once the exire time has been changed by bpexpdate.

      The time it would matter, is if the images were expired, and then imported - the expire time would revert back to the time set for the level number, relative to when the import was run.

      Do not ever mix retentions on tapes, short term it may help, long term you will use a lot more media.

      What you could do is reduce the number of partially full media for the volume pools to the same number, as the number of consecutive write drives in the storage unit(s).  For example, if you had 5 drives, set this value to 5 (in the volume pool) - this means that no more than 5 tapes are ever allowed to be partially full, meaning that you would have to fill a tape before another could be used.  Having 5, means that all tape drives can be used at once.

      It is not 100% guaranteed, there are times you may use a few more tapes than 5, but it should reduce the number of tapes used on average.