[linux-lvm] vgdisplay - checksum error - what does it mean?
bluca at comedia.it
Sat Feb 17 12:56:44 UTC 2007
On Fri, Feb 16, 2007 at 10:44:54AM +0100, Tomasz Chmielewski wrote:
>>>So this basically means, that LVM was set up on /dev/sda2 some time
>>>ago, but it was never removed from there - instead, RAID-10 was set up
>>>on that partition?
>>I don't think so. if sda2 is part of a raid10 md array probably the
>>beginning sector of the md device maps to the beginning sector of the
>>real device, hence lvm will find an lvm signature on /dev/sda2.
>Is there a way to check if it's really the case?
>There's something wrong with /dev/sda2 - lvmdiskscan claims it's a
>371.58 GB LVM physical volume, while /dev/md2 is the physical volume I use.
> /dev/sda2 [ 371.58 GB] LVM physical volume
> /dev/md2 [ 743.16 GB] LVM physical volume
>>>Should I do something to fix the things? What?
>>yes, re-enable md_component_detection in lvm.conf, why did you disable
>Certainly I didn't touch anything in /etc/lvm/*.
>If I look into /etc/lvm/lvm.conf, it says:
> # By default, LVM2 will ignore devices used as components of
> # software RAID (md) devices by looking for md superblocks.
> # 1 enables; 0 disables.
> md_component_detection = 1
>So the problem is somewhere else. Where?
with md_component_detection enabled lvm should ignore /dev/sda2.
can you send the output of lvmdiskscan -vvv?
>BTW, the machine is running Debian etch (ARM port).
mmm i don't have an arm maybe this is the issue why lvm does not
understand that sda2 is a md component?!?
>"smartctl" says all four disks are fine (they are quite new, too), so
>it's definitely not a hardware problem.
sure it is not an hw problem do not worry.
>I guess one way to fix it would be mark all partitions faulty on
>/dev/sda, and then, to recreate the RAIDs.
>But I'm curious to know how could I handle such a situation if I didn't
what would it fix? you have no problem except lvm2 believing sda2 is an
lvm volume which is not.
Luca Berra -- bluca at comedia.it
Communication Media & Services S.r.l.
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