2 Replies Latest reply: Apr 2, 2013 9:54 AM by Cindys-Oracle RSS

    ZFS zpool general question: how to make mirror with jbod

    1000414
      Hi!

      For instance, I have this configuration:

      NAME STATE READ WRITE CKSUM
      data ONLINE 0 0 0
      ....Disk_4TB ONLINE 0 0 0

      I.e. my pool consist of 4TB-disk.

      And I also have two disks: 3TB and 1TB. And I want to mirror these 2 disks with my 4TB-disk.

      How do I make a mirror like this (for instance):
      NAME STATE READ WRITE CKSUM
      data ONLINE 0 0 0
      ....mirror-0
      ........Disk_4TB
      .........JBOD
      ............Disk_1TB
      ............Disk_3TB

      I would be grateful for your response.

      Edited by: 997411 on 01.04.2013 22:55
        • 1. Re: ZFS zpool general question: how to make mirror with jbod
          Nik
          Hi.
          It's not possible.
          Read ZFS Administration Guide.


          For stupid resons possible solution:
          Split Disk_4TB to two slices : 1TB and 3 TB.
          Mirror every part with corresponded disk and concatanate this mirrors.

          Regards.
          • 2. Re: ZFS zpool general question: how to make mirror with jbod
            Cindys-Oracle
            Because the 4 TB disk is already in use, you can't attach disks that are smaller in size to the existing 4 TB pool. If the disks were equivalent in size, then yes, this is how you can created a mirrored pool after a non-redundant pool is created by attaching disks
            with zpool attach.

            You could start over and use all 3 disks, but the pool size would be constrained to the smallest disk, the 1 TB disk. You would end up with a mirrored pool of 3 disks, with a total size of 1 TB.

            # zpool create pool mirror Disk_1TB Disk_3TB Disk_4TB

            Without any additional disks, reconfiguring this pool with active data would involve the following steps:

            1. Copy the data to a new pool on the 3 TB disk.
            2. Destroy the pool with the 4 TB disk.
            3. Create a pool with the 1 TB disk and 4 TB disk:
            # zpool create pool mirror Disk_1TB Disk_4TB
            4. Copy the data over to the new mirrored pool.
            5. Destroy the pool created in step 1.
            6. Attach the remaining disk to the new pool:
            # zpool attach pool Disk_1TB Disk_3TB

            Thanks, Cindy