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Cylon_R's avatar
Cylon_R
Level 3
8 years ago

BE 16 Synthetic Backups questions?? can anyone help?

My question is in regards to Synthetic Backups and their requirement on the baseline backup.  We will be using the tape method (not disk storage method) which will require the baseline backup image to create a synthetic backup.  If this baseline image consists of say, 19 tapes, and I want to do a weekly synthetic full backup… do I need to keep those 19 tapes for the baseline image in the tape library all the time?

 

The document I’m referencing is here: https://www.veritas.com/support/en_US/article.v53928715_v113799574

  • Colin_Weaver's avatar
    Colin_Weaver
    8 years ago

    The first synthetic full combines the baseline backup with one or more synthetic enabled, incremental backups

    All subsequent synthetic full backups combine the previous synthetic full wit one of more synthetic enabled, incremental backups

    A point to be aware of: if your overall backup is a huge number of files, then we have seen situations where the gathering of the synthetic information, whilst running the incremental backup job, makes this job exceedingly long -  even to the point where there is no benefit to using the synthetic mechanism. As such I strongly suggest doing proof of concept tests with Backup Exec in trialware and before implementing as a final solution.

     

     

  • Colin_Weaver's avatar
    Colin_Weaver
    Moderator
    8 years ago

    The first synthetic full combines the baseline backup with one or more synthetic enabled, incremental backups

    All subsequent synthetic full backups combine the previous synthetic full wit one of more synthetic enabled, incremental backups

    A point to be aware of: if your overall backup is a huge number of files, then we have seen situations where the gathering of the synthetic information, whilst running the incremental backup job, makes this job exceedingly long -  even to the point where there is no benefit to using the synthetic mechanism. As such I strongly suggest doing proof of concept tests with Backup Exec in trialware and before implementing as a final solution.

     

     

  • pkh's avatar
    pkh
    Moderator
    8 years ago

    Since you are using tapes, do pay attention to the notes at the end of the technical note that you referenced.

  • Mr_Momo's avatar
    Mr_Momo
    Level 3
    7 years ago

    We do synthetic backups all the time, but on disk storage.

    In basic terms if you do a full backup on weekend 1, incrementals between, then synthetic on weekend 2 - it combines the full from week 1 with the subsequent incrementals to create the synthetic on weekend 2.

    Weekend 3 uses the weekend 2 synthetic and subsequent incrementals. Weekend 1 tapes are no longer required and can be expired. You could set them to expire on the day after the weekend 2 synthetic completes.

    So I would expect if your weekend 2 backup set is 19 tapes - they'll need to remain in the library until that backup set is no longer required.

    Synthetic backups make far more sense on disk storage to be honest.