[linux-lvm] Big question ...

[Martial Paupe]

Hello Bryn,

On Wednesday 22 November 2006 23:29, Bryn M. Reeves wrote:
I think that you speak about LVM2. I use RHES 3.5 and the version of lvm are 
lvm-1.0.8-14.


> Hello Martial,
>
> You should be able to remove a PV from a volume group with vgreduce even
> when it is inactive, as long as the PV is still present on the system:
>
> [root ~]# vgchange -an s0
>   0 logical volume(s) in volume group "s0" now active
> [root ~]# vgreduce s0 /dev/loop1
>   Removed "/dev/loop1" from volume group "s0"

vgchange -an VG_vobs
vgchange -- volume group "VG_vobs" successfully deactivated

 vgreduce VG_vobs /dev/emcpowera1
vgreduce -- ERROR: volume group "VG_vobs" doesn't exist
>
> If the PV is no longer present, this won't work though:
>
> [root ~]# losetup -d /dev/loop1
> [root ~]# vgreduce s0 /dev/loop1
>   Couldn't find device with uuid 'Tzx4n9-iA60-yu3U-9oRe-R0jh-RBb4-Sw8EmF'.
>   Couldn't find all physical volumes for volume group s0.
>   Couldn't find device with uuid 'Tzx4n9-iA60-yu3U-9oRe-R0jh-RBb4-Sw8EmF'.
>   Couldn't find all physical volumes for volume group s0.
>   Volume group "s0" doesn't exist
>
> In this case, you can make the volume group consistent again with
> "--removemissing":
 I don't have this option. I can't do that

>
> [root ~]# vgreduce --removemissing s0
>   Couldn't find device with uuid 'Tzx4n9-iA60-yu3U-9oRe-R0jh-RBb4-Sw8EmF'.
>   Couldn't find all physical volumes for volume group s0.
>   Couldn't find device with uuid 'Tzx4n9-iA60-yu3U-9oRe-R0jh-RBb4-Sw8EmF'.
>   Couldn't find all physical volumes for volume group s0.
>   Couldn't find device with uuid 'Tzx4n9-iA60-yu3U-9oRe-R0jh-RBb4-Sw8EmF'.
>   Wrote out consistent volume group s0
>
> Be aware though that if the PV you want to remove was actually in use
> you risk loosing whatever data was stored on it by this method - if
> possible get the PV back on the system and use the normal vgreduce.
>
> If this doesn't help then it would be useful to know what versions of
> LVM2 and device-mapper you are using and what distribution this is on.
-- 
Martial Paupe
Kudelski Group
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