LVM / DiskSuite question

From: Georges Tomazi (gt_at_diapason.com)
Date: 01/30/05 

Date: Sun, 30 Jan 2005 17:24:58 +0100

Hi -

Last night I had a problem with a Solaris 9 server. A 67 Gb slice (on a 73 Gb
RAID-1 disk) failed and the slice was taken over by a hot spare. This
morning, metastat was showing the following :

# metastat d3

d3: Mirror
    Submirror 0: d33
      State: Okay
    Submirror 1: d43
      State: Okay
    Pass: 1
    Read option: roundrobin (default)
    Write option: parallel (default)
    Size: 141161948 blocks (67 GB)

d33: Submirror of d3
    State: Okay
    Hot spare pool: hsp000
    Size: 141161948 blocks (67 GB)
    Stripe 0:
        Device Start Block Dbase State Reloc Hot Spare
        c0t2d0s3 0 No Okay Yes c0t4d0s7

d43: Submirror of d3
    State: Okay
    Hot spare pool: hsp000
    Size: 141161948 blocks (67 GB)
    Stripe 0:
        Device Start Block Dbase State Reloc Hot Spare
        c0t3d0s3 0 No Okay Yes

Device Relocation Information:
Device Reloc Device ID
c0t4d0 Yes id1,sd@w5005076719c8d3c6
c0t3d0 Yes id1,sd@w0010b9ff130f7a12

# metastat hsp000
hsp000: 7 hot spares
        Device Status Length Reloc
        c0t4d0s0 Available 2124024 blocks Yes
        c0t4d0s1 Available 2124024 blocks Yes
        c0t4d0s3 Available 20995464 blocks Yes
        c0t4d0s4 Available 20995464 blocks Yes
        c0t4d0s5 Available 48260352 blocks Yes
        c0t4d0s6 Available 48260352 blocks Yes
        c0t4d0s7 In use 143967768 blocks Yes

Device Relocation Information:
Device Reloc Device ID
c0t4d0 Yes id1,sd@w5005076719c8d3c6

However, the disk seems to be OK (less than a year old). No bad blocks and
the others slices on it are just fine. So before physically replacing it, I'd
like to put back the submirror on it and see how it goes. If it fails again
I'll replace it.

I'm just not 100% sure how to enable again the mirror. It would be great if
someone could confirm if that's the right way to do it:

# metadetach d3 d33 (detaching the failed submirror)
# metaclear d33 (clearing it)
# metainit d33 1 1 c0t2d0s3 -h hsp000 (creating the submirror and allocating
again the hot spare pool)
# metattach d3 d33 (attaching and synchronizing the submirror)

I'm not sure about the third step. In Sun's documentation, they suggest a
command like "metainit d33 2 1 c0t2d0s3 1 c0t3d0s3".

I'm concerned about the risk of loosing the data on the working submirror
(c0t3d0s3)...

After enabling again the submirror, the hot spare should be automatically
released, right ?

Any help would be appreciated...

Thanks,

Georges 

-- 
Georges Tomazi - gt@diapason.com