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GPM's avatar
GPM
Level 3
8 years ago

Tape Library four tape drives

I have a library, I divided it into four Partitions. Partition 1, Partition 2, Partition3, Partion4. Four drives in the library. Drive 1 assigned to Partition 1  etc.... I assigned one drive to each partition. I run the duplication job -  from Partition1 (Drive1) to Partition 2 (Drive2). In this job BackupExec for write always used Drive2 only. Its good. But for read (if Drive1 busy) BE used Drive3 or Drive4. This bad!! For Partition1 assign Drive1 only!

I have five Jobs start in 12:00 pm

job1 - backup to disk, duplicate to Partition1 (Drive1) and after duplicate from Partition1 to Partition2 (Drive2).

Job2 - backup to disk, duplicate to Partition3 (Drive3) and after duplicate from Partition3 to Partition4 (Drive4).

Job3 - backup to disk, duplicate to Partition1 (Drive1) and after duplicate from Partition1 to Partition2 (Drive2).

Job4 - backup to disk, duplicate to Partition3 (Drive3) and after duplicate from Partition3 to Partition4 (Drive4).

Job5 - backup to disk, duplicate to Partition3 (Drive3) and after duplicate from Partition3 to Partition4 (Drive4).

If Drive1 busy BE used Drive3 or Drive4 for read data in Job1...  stage  - duplicate from Partition1(Drive1) to Partition2 (Drive2). - This bad. Please help. When Job1 used Drive3 or Drive4 other jobs (Job2, Job4, Job5) - mode waiting...not possible for write idle devices...

16
Windows Server 2016

3 Replies

  • Larry_Fine's avatar
    Larry_Fine
    Level 6
    8 years ago

    I think you have set up a very delicate situation, with 5 simultaneous multi-stage jobs targetted to 4 drives/partitions.

    My first suggestion would be to use partitions (logical libraries) created in the library itself, also called hardware partitioning.  Backup Exec partitions (software partitions) are generally only accurate for backups.

    Alternatives would be to use media sets, instead of Backup Exec partitions.  Or to use staggered start times to avoid drive contention and having things queued.

     

    • GPM's avatar
      GPM
      Level 3
      8 years ago

      1) Hardware partitions - good idea. I will think about this! Thanks!

      2) I really use MediaSet1 for Partiton1, 2 for 2 etc... and have this problem. Why media set help drives contention? What is your idea?

       

      • Larry_Fine's avatar
        Larry_Fine
        Level 6
        8 years ago
        GPMwrote:

        1) Hardware partitions - good idea. I will think about this! Thanks!

        2) I really use MediaSet1 for Partiton1, 2 for 2 etc... and have this problem. Why media set help drives contention? What is your idea? 

        If you fully embrace MediaSets, you may find that you do not need partitions, but it depends upon your needs.  I don't see a typical need to restrict jobs to certain tape drives.  If the tape drives are all the same generation/model, then jobs should just them first-come-first-serve.

        I suspect that most people attempt to use software partitions as one method to group media or they think it will make it easier to export media, but the limitations of software partitions outweigh the benefits for many users once they get fully into it.