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Ben_B_NZ's avatar
Ben_B_NZ
Level 2
9 years ago

Backup using more tapes than it should

Hi,

I currently run a weekly backup of our servers that is ~3TB is size, onto LT04 tapes. Even if there is zero compression, that should only take around 4 tapes. Currently it takes  usually 6, but sometimes 7. Just wondering if anyone has run into a similar problem or knows where I may have a setting wrong to cause it to span so many tapes.

Basic rundown of backup:

Using Backup Exec 2014

Run 4 seperate backup jobs

Backing up 3 servers with a normal backup agent + 1 SQL Server 

Noticed recently that even though the SQL server job is less than 100GB it takes more than 1 tape to get the backup for that server completed, and the 1 server with >1TB of data takes 3+ tapes

I have tried doing 1 job for all 4 servers, which cut down the tapes but stuffed up the daily differentials, so reverted to individual jobs to ensure we have a proper differential job each day

Could I run the 1 job for all servers as the full backup, then the 4 seperate jobs for the daily differential?

TIA

  • Colin_Weaver's avatar
    Colin_Weaver
    Moderator
    9 years ago

    You gave to link differentials with the full so no you cannot split in the way you ask.

     

    With regards your tape handling

    1) Are you using a library and is yes how many drives has it got?

    2) Do you start the 4 separate backup jobs at the same time?

    3) Do you know if the first tape used by each of the 4 jobs is being overwriteen or appended to  (the job logs should show this)?

     

     

    • Ben_B_NZ's avatar
      Ben_B_NZ
      Level 2
      9 years ago

      Hi Colin,

      Thanks for replying, in answer to your questions

      1. We use a library with 2 banks, 24 slots and 1 drive

      2. Yes, I stagger the jobs an hour apart, which used to work fine and used 4-5 tapes, but has now gone to 6-7 tapes with the same amount of data being backed up

      3. The jobs are set to Append to media, overwrite if no media is available

  • Larry_Fine's avatar
    Larry_Fine
    Level 6
    9 years ago

    Are your tapes getting marked as "media full"?  Or are your tapes not getting 100% full?

    If they are truly getting full, then the focus is on the data source, compression, etc.  if they are getting 100% full, but actually holding less data than the native LTO4 capaity, then you may have a clogged tape drive head.  See http://www.veritas.com/docs/000017157

    If they are not getting 100% full, then the focus is on your job strategy (timing, append vs overwrite, as Colin mentioned)

     

    • Ben_B_NZ's avatar
      Ben_B_NZ
      Level 2
      9 years ago

      Hi Larry,

      The media says ifs full and uses 780GB of 781GB available, just running the cleaning tape through a few times now, plus will chuck in a new cleaning tape and see if that changes things

      Thanks for the help

  • Ben_B_NZ's avatar
    Ben_B_NZ
    Level 2
    9 years ago

    By way of update, ran the cleaning tape 5 times before the full backup jobs kicked off this past weekend and still having dramas with too many tapes

    My manager is going to order in a new cleaning tape, so I will try that as well

    Otherwise things are looking shady still