Re: blkid and partition problem

[Bill Davidsen <davidsen@tmr.com>]

Tim Bostrom wrote:
> Looking for some help.  I'm trying to start my array but just noticed
> that somehow my the UUID got assigned to my physical drive and not the
> partition.  The partition doesn't show up in /dev/.  Drive sdm has a
> valid partition, but blkid is set on the physical disk.
>
> /dev/sdm is the drive causing issue.  The partition is there (see
> fdisk output below).  It contains data so I'd like to not have to
> completely wipe the drive.  Is there any option to fix this?
>
> blkid output (see /dev/sdm):
> ----------------------
> /dev/sda1: UUID="dd8018e3-2939-4236-9a63-c36d6df9cf80" TYPE="ext3"
> /dev/sda2: UUID="287f5ab6-d463-43a2-a3b2-7bf789dd8744" TYPE="ext3"
> /dev/sda3: UUID="336a1681-af86-401d-946e-201ae37780fe" TYPE="swap"
> /dev/sdb1: UUID="cdaba8bd-8094-3c6a-ab2f-edca3ef56cfb" TYPE="linux_raid_member"
> /dev/sdc1: UUID="cdaba8bd-8094-3c6a-ab2f-edca3ef56cfb" TYPE="linux_raid_member"
> /dev/sdd1: UUID="cdaba8bd-8094-3c6a-ab2f-edca3ef56cfb" TYPE="linux_raid_member"
> /dev/sde1: UUID="cdaba8bd-8094-3c6a-ab2f-edca3ef56cfb" TYPE="linux_raid_member"
> /dev/sdf1: UUID="649526d8-828a-57b4-ab2f-edca3ef56cfb" TYPE="linux_raid_member"
> /dev/sdg1: UUID="649526d8-828a-57b4-ab2f-edca3ef56cfb" TYPE="linux_raid_member"
> /dev/sdh: UUID="7ea182f5-0c31-3e24-adba-30185bcf511e" LABEL="1"
> TYPE="linux_raid_member"
> /dev/sdi: UUID="7ea182f5-0c31-3e24-adba-30185bcf511e" LABEL="1"
> TYPE="linux_raid_member"
> /dev/sdj1: UUID="f911d5fb-8cf2-0015-ab2f-edca3ef56cfb" TYPE="linux_raid_member"
> /dev/sdk1: UUID="f911d5fb-8cf2-0015-ab2f-edca3ef56cfb" TYPE="linux_raid_member"
> /dev/md0: LABEL="teradata" UUID="2e7624ad-f059-4e35-a18a-eb8ffa645d54"
> TYPE="ext3"
> /dev/sdm: UUID="db34c204-6c5a-7156-28d0-d68913f396a5" LABEL="0"
> TYPE="linux_raid_member"
> /dev/md1: UUID="eea5390f-8f24-4a82-b899-7924fb126a5b" TYPE="ext3"
>
>
> fdisk -l /dev/sdm output:
> ------------------
> Disk /dev/sdm: 1000.2 GB, 1000204886016 bytes
> 255 heads, 63 sectors/track, 121601 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
> Disk identifier: 0x000f2387
>
>    Device Boot      Start         End      Blocks   Id  System
> /dev/sdm1               1      121601   976760001   fd  Linux raid autodetect
>
>
>  ls -l /dev/sd*
> brw-rw---- 1 root disk 8,   0 2010-05-21 16:32 /dev/sda
> brw-rw---- 1 root disk 8,   1 2010-05-21 16:32 /dev/sda1
> brw-rw---- 1 root disk 8,   2 2010-05-21 16:32 /dev/sda2
> brw-rw---- 1 root disk 8,   3 2010-05-21 16:32 /dev/sda3
> brw-rw---- 1 root disk 8,  16 2010-05-21 16:32 /dev/sdb
> brw-rw---- 1 root disk 8,  17 2010-05-21 16:32 /dev/sdb1
> brw-rw---- 1 root disk 8,  32 2010-05-21 16:32 /dev/sdc
> brw-rw---- 1 root disk 8,  33 2010-05-21 16:32 /dev/sdc1
> brw-rw---- 1 root disk 8,  48 2010-05-21 16:32 /dev/sdd
> brw-rw---- 1 root disk 8,  49 2010-05-21 16:32 /dev/sdd1
> brw-rw---- 1 root disk 8,  64 2010-05-21 16:32 /dev/sde
> brw-rw---- 1 root disk 8,  65 2010-05-21 16:32 /dev/sde1
> brw-rw---- 1 root disk 8,  80 2010-05-21 16:32 /dev/sdf
> brw-rw---- 1 root disk 8,  81 2010-05-21 16:32 /dev/sdf1
> brw-rw---- 1 root disk 8,  96 2010-05-21 16:32 /dev/sdg
> brw-rw---- 1 root disk 8,  97 2010-05-21 16:32 /dev/sdg1
> brw-rw---- 1 root disk 8, 112 2010-05-21 16:32 /dev/sdh
> brw-rw---- 1 root disk 8, 128 2010-05-21 16:32 /dev/sdi
> brw-rw---- 1 root disk 8, 144 2010-05-21 16:32 /dev/sdj
> brw-rw---- 1 root disk 8, 145 2010-05-21 16:32 /dev/sdj1
> brw-rw---- 1 root disk 8, 160 2010-05-21 16:32 /dev/sdk
> brw-rw---- 1 root disk 8, 161 2010-05-21 16:32 /dev/sdk1
> brw-rw---- 1 root disk 8, 176 2010-05-21 16:32 /dev/sdl
> brw-rw---- 1 root disk 8, 192 2010-05-21 16:32 /dev/sdm
>
>
>
> Any help is greatly appreciated.
>   

Let me propose a cause for this. Assume that after partitioning sdm you 
created an array, and when giving the members you typed /dev/sdm rather 
than /dev/sdm1. Sound possible? You might try assembling an array with 
the members and give /dev/sdm instead of /dev/sdm1, specifying read-only 
to prevent issues.

My reasoning is that using the whole disk you would write over the UUID 
on the partition, but the partition table might be safe.

Corrections welcome.

-- 
Bill Davidsen <davidsen@tmr.com>
  "We can't solve today's problems by using the same thinking we
   used in creating them." - Einstein