[linux-lvm] setting VG UUID

[linux-lvm] setting VG UUID

[Navindra Umanee]

Hi!

After figuring out that my all my PVs were lacking UUIDs, I used this
hack from Heinz to correct the situation:

http://lists.sistina.com/pipermail/linux-lvm/2002-January/010521.html

(Alasdair also kindly provided a patch to handle the situation in LVM2.)

Now my VG itself is still lacking a UUID and this causes problems such
as vgcfgrestore refusing to continue.  Is there any way I can update
my VG UUID?

I also have this problem where my PV's are using different system ids:

VG:        localhost.localdomain1073237462
/dev/hda6: localhost.localdomain1073237462 (same)
/dev/hda7: localhost.localdomain1073237466
/dev/hda8: localhost.localdomain1073237470
/dev/hda9: localhost.localdomain1073237474

Is there a way of fixing this?

Thanks,
Navin.

Re: [linux-lvm] setting VG UUID

[Navindra Umanee]

> After figuring out that my all my PVs were lacking UUIDs, I used this
> hack from Heinz to correct the situation:
> 
> http://lists.sistina.com/pipermail/linux-lvm/2002-January/010521.html
> 
> (Alasdair also kindly provided a patch to handle the situation in LVM2.)
> 
> Now my VG itself is still lacking a UUID and this causes problems such
> as vgcfgrestore refusing to continue.  Is there any way I can update
> my VG UUID?

For the record, I'm absolutely crazy, but I fixed this by doing:

echo "deadbeefdeadbeefdeadbeefdeadbeef"|dd of=/dev/hda6 obs=1 seek=4096 count=32
echo "deadbeefdeadbeefdeadbeefdeadbeef"|dd of=/dev/hda7 obs=1 seek=4096 count=32
echo "deadbeefdeadbeefdeadbeefdeadbeef"|dd of=/dev/hda8 obs=1 seek=4096 count=32
echo "deadbeefdeadbeefdeadbeefdeadbeef"|dd of=/dev/hda9 obs=1 seek=4096 count=32

So much for universal uniqueness...  but now finally LVM2 is happy to
accept my LVM1 partitions!  Woohoo!!

For the record, I created my LVM1 partitions with Linux Mandrake 9.2.
So I anticipate other people will be having this kind of fun.  :-)

One inconvenience I still seem to have is that /dev/bytepool/ is now
filled with symlinks and when I boot back to Linux 2.4 with LVM1 (no
device-mapper), it fails to mount the partitions because of this.
Cleaning /dev/bytepool/ and rebooting seems to fix this.

Should "vgchange -a n" maybe clean up these symlinks?

Cheers,
Navin.

Re: [linux-lvm] setting VG UUID

[Alasdair G Kergon]

On Wed, Jan 07, 2004 at 09:24:15AM -0500, Navindra Umanee wrote:
> For the record, I'm absolutely crazy, but I fixed this by doing:
> 
> echo "deadbeefdeadbeefdeadbeefdeadbeef"|dd of=/dev/hda6 obs=1 seek=4096 count=32

> So much for universal uniqueness...
The VG UUIDs *are* meant to all be the same on devices that are part of the
same VG.  It's the PV UUIDs that differ.
 
> For the record, I created my LVM1 partitions with Linux Mandrake 9.2.
Could /dev/urandom have been missing when pvcreate was run?
We think that would explain the symptoms.

> Should "vgchange -a n" maybe clean up these symlinks?
It's supposed to do.
 
Alasdair
-- 
agk@redhat.com

Re: [linux-lvm] setting VG UUID

[Navindra Umanee]

Alasdair G Kergon <agk@redhat.com> wrote:
> > So much for universal uniqueness...
> The VG UUIDs *are* meant to all be the same on devices that are part of the
> same VG.  It's the PV UUIDs that differ.

Oh, I realise that.  Just a small joke about my non-random choice of
UUID... :)

> > For the record, I created my LVM1 partitions with Linux Mandrake 9.2.
> Could /dev/urandom have been missing when pvcreate was run?
> We think that would explain the symptoms.

Good thought!  It's very possible since of course only a crippled
environment is available at install time.  I'll try to verify it
later.

> > Should "vgchange -a n" maybe clean up these symlinks?
> It's supposed to do.

Hmmm.  I've hacked my init scripts to do it in the meanwhile, but I
will pay closer attention to what happens next time I boot and report
back.

Happily, so far I don't see any reason to go back to Linux 2.4 though
and a quite a few reasons to stay in 2.6....

Cheers,
Navin.

Re: [linux-lvm] setting VG UUID

[Luca Berra]

On Wed, Jan 07, 2004 at 06:58:01AM -0500, Navindra Umanee wrote:
>Hi!
>
>After figuring out that my all my PVs were lacking UUIDs, I used this
>hack from Heinz to correct the situation:
>
>http://lists.sistina.com/pipermail/linux-lvm/2002-January/010521.html
>
>(Alasdair also kindly provided a patch to handle the situation in LVM2.)

is it possible to have a copy of this patch?
L.

-- 
Luca Berra -- bluca@comedia.it
        Communication Media & Services S.r.l.
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Re: [linux-lvm] setting VG UUID

[Navindra Umanee]

Luca Berra <bluca@comedia.it> wrote:
> >After figuring out that my all my PVs were lacking UUIDs, I used this
> >hack from Heinz to correct the situation:
> >
> >http://lists.sistina.com/pipermail/linux-lvm/2002-January/010521.html
> >
> >(Alasdair also kindly provided a patch to handle the situation in LVM2.)
> 
> is it possible to have a copy of this patch?

Up to Alasdair...  have you seen this problem too?

Remember, if your PV is lacking UUIDs, your VG probably is too and
that's going to cause problems as well.  

At least it did for me.

Cheers,
Navin.

Re: [linux-lvm] setting VG UUID

[Luca Berra]

On Thu, Jan 22, 2004 at 08:52:10PM -0500, Navindra Umanee wrote:
>Luca Berra <bluca@comedia.it> wrote:
>> >After figuring out that my all my PVs were lacking UUIDs, I used this
>> >hack from Heinz to correct the situation:
>> >
>> >http://lists.sistina.com/pipermail/linux-lvm/2002-January/010521.html
>> >
>> >(Alasdair also kindly provided a patch to handle the situation in LVM2.)
>> 
>> is it possible to have a copy of this patch?
>
>Up to Alasdair...  have you seen this problem too?
not personally, but i had some bug reports of similar problems.

>Remember, if your PV is lacking UUIDs, your VG probably is too and
>that's going to cause problems as well.  
yes, thanks for the useful info.

L.

-- 
Luca Berra -- bluca@comedia.it
        Communication Media & Services S.r.l.
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Re: [linux-lvm] setting VG UUID

[Alasdair G Kergon]

On Thu, Jan 22, 2004 at 10:49:23PM +0100, Luca Berra wrote:
> >After figuring out that my all my PVs were lacking UUIDs, I used this
> >hack from Heinz to correct the situation:
> >http://lists.sistina.com/pipermail/linux-lvm/2002-January/010521.html
> >(Alasdair also kindly provided a patch to handle the situation in LVM2.)
> is it possible to have a copy of this patch?
 
It's already in LVM2 CVS, together with patches to *change tools to let
you change the UUIDs to new random ones (not to be used while any
LVs are active).

Alasdair
-- 
agk@uk.sistina.com

Re: [linux-lvm] setting VG UUID

[Luca Berra]

On Fri, Jan 23, 2004 at 01:35:58PM +0000, Alasdair G Kergon wrote:
>On Thu, Jan 22, 2004 at 10:49:23PM +0100, Luca Berra wrote:
>> >After figuring out that my all my PVs were lacking UUIDs, I used this
>> >hack from Heinz to correct the situation:
>> >http://lists.sistina.com/pipermail/linux-lvm/2002-January/010521.html
>> >(Alasdair also kindly provided a patch to handle the situation in LVM2.)
>> is it possible to have a copy of this patch?
> 
>It's already in LVM2 CVS, together with patches to *change tools to let
>you change the UUIDs to new random ones (not to be used while any
>LVs are active).
>
thanks a lot
L.

-- 
Luca Berra -- bluca@comedia.it
        Communication Media & Services S.r.l.
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Re: [linux-lvm] setting VG UUID

[Dan Merillat]

On Thu, 08 Jan 2004, Navindra Umanee wrote:

> Alasdair G Kergon <agk@redhat.com> wrote:
> > > Should "vgchange -a n" maybe clean up these symlinks?
> > It's supposed to do.
> 
> Hmmm.  I've hacked my init scripts to do it in the meanwhile, but I
> will pay closer attention to what happens next time I boot and report
> back.

It's probably trying to do it AFTER the kernel unmounts / (remounts RO)
Watch your shutdown, that's where I see "unable to BLA, read-only
filesystem" messages.   Since /dev gets cleaned up on boot I'm not too
worried about it.

--Dan