[SunHELP] Discrepancy in size of stripe and soft partition in SVM

[Paul Walsh]

System: SunFire V490, 2 x 146Gb disks + 200Gb LUN on EMC Clariion
O/S: Solaris 9
I have a metadevice (d53) which was originally a two-way mirror of 20Gb devices on the internal disks, to which I added
a 32Gb device from the SAN disk (with the intention of syncing the data then breaking the mirror before redefining it
using the SAN disk first):

# metastat d53
d53: Mirror
    Submirror 0: d253
      State: Okay
    Submirror 1: d153
      State: Okay
    Submirror 2: d213
      State: Okay
    Pass: 1
    Read option: roundrobin (default)
    Write option: parallel (default)
    Size: 41945472 blocks (20 GB)

d253: Submirror of d53
    State: Okay
    Size: 41945472 blocks (20 GB)
    Stripe 0:
        Device   Start Block  Dbase        State Reloc Hot Spare
        d243            0     No            Okay   No

d243: Soft Partition
    Device: c1t1d0s6
    State: Okay
    Size: 41945472 blocks (20 GB)
        Device     Start Block  Dbase Reloc
        c1t1d0s6          0     No    Yes

        Extent              Start Block              Block count
             0                 71316997                 41945472


d153: Submirror of d53
    State: Okay
    Size: 41945472 blocks (20 GB)
    Stripe 0:
        Device   Start Block  Dbase        State Reloc Hot Spare
        d143            0     No            Okay   No

d143: Soft Partition
    Device: c1t0d0s6
    State: Okay
    Size: 41945472 blocks (20 GB)
        Device     Start Block  Dbase Reloc
        c1t0d0s6          0     No    Yes

        Extent              Start Block              Block count
             0                 71313413                 41945472


d213: Submirror of d53
    State: Okay
    Size: 67108864 blocks (32 GB)
    Stripe 0:
        Device   Start Block  Dbase        State Reloc Hot Spare
        d113            0     No            Okay   No

d113: Soft Partition
    Device: c2t0d9s6
    State: Okay
    Size: 67108864 blocks (32 GB)
        Device     Start Block  Dbase Reloc
        c2t0d9s6          0     No    Yes

        Extent              Start Block              Block count
             0                113246212                  2097152
             1                220227728                 41952768
             2                308317843                 23058944


Device Relocation Information:
Device   Reloc  Device ID
c1t1d0   Yes    id1,ssd at w500000e0110840b0
c1t0d0   Yes    id1,ssd at w20000011c604e4a7
c2t0d9   Yes    id1,sd at w60060160249a1500c883fa8cfa50da11

Once the data re-sync'd, I detached and cleared one of the devices on the internal disks (d253 and the soft partition
d243). I then re-defined d243 as a 32g soft partition:


d243: Soft Partition
    Device: c1t1d0s6
    State: Okay
    Size: 67108864 blocks (32 GB)
        Device     Start Block  Dbase Reloc
        c1t1d0s6          0     No    Yes

        Extent              Start Block              Block count
             0                134245383                 67108864

Device Relocation Information:
Device   Reloc  Device ID
c1t1d0   Yes    id1,ssd at w500000e0110840b0

So far, so good. The soft partition is the same size in blocks as d213 / d113
BUT....
when I re-create d253, its size is smaller:

d253: Concat/Stripe
    Size: 67100544 blocks (31 GB)
    Stripe 0:
        Device   Start Block  Dbase     Reloc
        d243            0     No        No

d243: Soft Partition
    Device: c1t1d0s6
    State: Okay
    Size: 67108864 blocks (32 GB)
        Device     Start Block  Dbase Reloc
        c1t1d0s6          0     No    Yes

        Extent              Start Block              Block count
             0                134245383                 67108864

Device Relocation Information:
Device   Reloc  Device ID
c1t1d0   Yes    id1,ssd at w500000e0110840b0

Can anyone enlighten me as to why this happens? It's very frustrating!


-- 
Paul Walsh

Systems Manager (UNIX),
Information & Communication Technology,
Birmingham City University,
BIRMINGHAM B42 2SU, UK
Tel:    +44 (0)121 331 5708
Fax:    +44 (0)121 356 2875
Mobile: +44 (0)7974 150 421

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