1 Reply Latest reply: Apr 6, 2010 2:44 AM by 807567 RSS

    metastat output - What does "Start Block" value mean

    807567
      Hi all,
      I am just exploring the output of "metastat" command . I created 3 volumes as follows
      d80 - RAID5 Volume, d40- Stripped volume having interlace 64k, d20- Concatenated Volume.
      I have taken the full device for making all the above volumes.
      The "Start Block" as per sun documentation indicates "start block on which the slice begins"
      If I understand it literally the full device beings from Block number '0'.
      Why it shows different value of "Start Block" for different devices on different volume.

      Can anyone explain what exactly does the 'Start Block' mean?

      Thanks,
      -sarans


      bash-2.05# metainit d80 -r c3t3d6s2 c3t3d7s2 c3t3d8s2 -i 20k
      d80: RAID is setup
      bash-2.05# metastat d80
      d80: RAID
      State: Okay
      Interlace: 40 blocks
      Size: 2033280 blocks (992 MB)
      Original device:
      Size: 2034320 blocks (993 MB)
      Device Start Block Dbase State Reloc Hot Spare
      c3t3d6s2 2330 No Okay Yes
      c3t3d7s2 2330 No Okay Yes
      c3t3d8s2 2330 No Okay Yes

      Device Relocation Information:
      Device Reloc Device ID
      c3t3d6 Yes id1,sd@w60060480000190300174533030314430
      c3t3d7 Yes id1,sd@w60060480000190300174533030314431
      c3t3d8 Yes id1,sd@w60060480000190300174533030314432
      bash-2.05# metainit d40 1 3 c3t3d12s2 c3t3d13s2 c3t3d14s2 -i 64k
      d40: Concat/Stripe is setup
      bash-2.05# metastat d40
      d40: Concat/Stripe
      Size: 12268800 blocks (5.8 GB)
      Stripe 0: (interlace: 128 blocks)
      Device Start Block Dbase Reloc
      c3t3d12s2 0 No Yes
      c3t3d13s2 1920 No Yes
      c3t3d14s2 1920 No Yes

      Device Relocation Information:
      Device Reloc Device ID
      c3t3d12 Yes id1,sd@w60060480000190300174533030373332
      c3t3d13 Yes id1,sd@w60060480000190300174533030373333
      c3t3d14 Yes id1,sd@w60060480000190300174533030373334
      bash-2.05#
      bash-2.05# metainit d20 3 1 c3t3d21s2 1 c3t3d22s2 1 c3t3d23s2
      d20: Concat/Stripe is setup
      bash-2.05# metastat d20
      d20: Concat/Stripe
      Size: 6124800 blocks (2.9 GB)
      Stripe 0:
      Device Start Block Dbase Reloc
      c3t3d21s2 0 No Yes
      Stripe 1:
      Device Start Block Dbase Reloc
      c3t3d22s2 1920 No Yes
      Stripe 2:
      Device Start Block Dbase Reloc
      c3t3d23s2 1920 No Yes

      Device Relocation Information:
      Device Reloc Device ID
      c3t3d21 Yes id1,sd@w60060480000190300174533030444445
      c3t3d22 Yes id1,sd@w60060480000190300174533030444446
      c3t3d23 Yes id1,sd@w60060480000190300174533030444530
      bash-2.05#
        • 1. Re: metastat output - What does "Start Block" value mean
          807567
          I did further analysis on this.
          For Concat & Stripped volumes ( d20 & d40), SVM is using the 1st device from Start Block "0". Then for all other subsequent devices, it is leaving the 1st cylinder (i.e 1920 blocks) and using the rest of the space available on the disk.

          But for RAID5 volumes, SVM leaves 2330 blocks from the beginning of all devices and using the rest of the space.

          Anyone knows the reason for this ?

          This can be found out using prtvtoc & devinfo cmds

          bash-2.05# prtvtoc /dev/rdsk/c3t3d21s2
          * /dev/rdsk/c3t3d21s2 partition map
          *
          * Dimensions:
          * 512 bytes/sector
          * 128 sectors/track
          * 15 tracks/cylinder
          * 1920 sectors/cylinder
          * 1066 cylinders
          * 1064 accessible cylinders
          *
          * Flags:
          * 1: unmountable
          * 10: read-only
          *
          * First Sector Last
          * Partition Tag Flags Sector Count Sector Mount Directory
          0 2 00 0 67200 67199
          1 3 01 67200 132480 199679
          2 5 01 0 2042880 2042879
          6 4 00 199680 1843200 2042879
          bash-2.05#
          bash-2.05# devinfo -i /dev/rdsk/c3t3d21s2
          /dev/rdsk/c3t3d21s2 0 0 1920 512 4