Forum Discussion

Benni82's avatar
Benni82
Level 2
9 years ago

BackupExec Best practice: Backup to disk (raid 0) - How many write connections?

Hi, today we changed the place where our backup server stores the backups, from a single USB disk to an USB connected Raid 0 USB Case (2x8 TB HDD). Wich would be best practice for the setting "Simultaneous write operations/Concurrent Write Sessions"? (dont exactly know how its in english, found diefferent posts, in german its "Gleichzeitige Schreibvorgänge") Default setting is 2. I wonder if it wouldnt be better to set it to 1 and let the raid do the job of writing in 2 streams to the 2 disks. What do you think? Or maybe someone allready tested it and can say it for sure? Thx in advance for any reply!
  • CraigV's avatar
    CraigV
    Moderator
    9 years ago
    I would never backup to a RAID configuration of Raid 0. Raid 0 is there for very fast access to disk when you don't care what happens with the data on that disk. If 1 disk fails, you lose all your backups. Consider changing this to RAID1 at least! You might lose half the disks, but can tolerate a single failure. Leave it at the default, and then change accordingly. Changing it to 1 won't make any difference...RAID0 just reads and writes faster and won't split the stream equally across 2 disks. Thanks!
  • Larry_Fine's avatar
    Larry_Fine
    Level 6
    9 years ago

    I believe that "Simultaneous write operations/Concurrent Write Sessions" is just a limit of how many write operations (i.e. backup jobs) that Backup Exec will allow to run at once.  Basically similar to the limit of how many tape drives you have in your tape library limits the number of jobs that can run at once.

    If you are only running a single backup job, then the setting has no performance impact.  If you want to run multiple jobs simultaneously, then you will need to test on your particular environment to find the sweet spot for total optimum performance.

    • Benni82's avatar
      Benni82
      Level 2
      9 years ago

      thx for your awnsers.

       

      CraigV

      Direct after backup2disk theres a clone job to tape, so the raid is just a temporary solution and for that should be as fast as possible.

       

      Larry_Fine

      assumed something like this allready but wasnt sure.

       

      Last night the disk job ran with avarage 5,5GB/min with setting to 2.

      Will change it to 1 just for testing purpose and reply the result.

      • Benni82's avatar
        Benni82
        Level 2
        9 years ago

        changed it to 1: no siginificant changes (sometimes a little bit faster/slower) so it seems, this option is really only to specify how many jobs can simultaneously write to this disk an not how many write streams are established.