[linux-lvm] lvm2 confused about double UUID

[Ron Johnson]

On 2009-07-26 19:21, Christian Kujau wrote:
> The subject says LVM is confused, but maybe it's me who is confused:
> 
> I once had a PV made from a single /dev/sdb and all was well. This sdb 
> however was really a 2 disk RAID1 which is now split up, the system now 
> sees both disks, sdb and sdc. Of course, sdb and sdc still have the same 
> UUID:

How did you split the mirrorset?


> # blkid  | egrep 'sd[bc]'
> /dev/sdb1: UUID="1O2Tkq-9Jy8-VfuZ-uzFh-1f6v-iVBD-hcK6Vq" TYPE="lvm2pv" 
> /dev/sdc1: UUID="1O2Tkq-9Jy8-VfuZ-uzFh-1f6v-iVBD-hcK6Vq" TYPE="lvm2pv"
> 
> I decided to continue to use the VG that was set up on the PV, but since 
> lvm comlained[0] about finding the same UUID on more than one device, I 
> tried to instruct lvm to just use sdb for the VG:

Did you reformat sdc before reusing it?  (That should give it a new 
UUID.)

> # grep filter /etc/lvm/lvm.conf | grep -v \#
>    filter = [ "r|^/dev/sdc1$|", "r|/dev/.*/by-path/.*|", \
>               "r|/dev/.*/by-id/.*|", "a/.*/" ]
> 
> Now everything looks fine, no more lvm warnings, vg02 seems to use sdb1, 
> exactly as I wanted:
> 
> # pvs
>   PV         VG   Fmt  Attr PSize   PFree  
>   /dev/sda2  vg01 lvm2 a-   111.67G   9.27G
>   /dev/sdb1  vg02 lvm2 a-   931.46G 137.46G
> 
> 
> But when I access vg02, I can clearly see I/O to/from sdc! I'd really like 
> to use sdc for something else now that sdb is used for vg02, but I'm afraid to 
> do something to sdc, as it still being used - although I don't know why.
> 
> Any ideas?
> 
> Christian.
> 
> # lvm version
>   LVM version:     2.02.26 (2007-06-15)
>   Library version: 1.02.20 (2007-06-15)
>   Driver version:  4.12.0
> # uname -r
> 2.6.24-24-xen                      <-- Ubuntu/8.04

Shouldn't you be asking the Ubuntu forum?

> 
> [0] e.g.
>    Found duplicate PV 1O2Tkq9Jy8VfuZuzFh1f6viVBDhcK6Vq: using 
>    /dev/disk/by-path/pci-fw1.1-scsi-0:0:0:1-part1 not /dev/sdb1


-- 
Scooty Puff, Sr
The Doom-Bringer