Re: [linux-lvm] Debian 64bit get a "Volume vg0 not found" message

[Brent Clark <brentgclarklist@gmail.com>]

Thank you so much for you help and replies.

I ended, up taking a initrd.img-2.6.32-5-amd64 from another server and placing it in /boot.
And that worked.

But what I dont understand is, in the chroot environment, I restalled the kernel, lvm2 packages, ran mkinitramfs and update-initramfs. Nothing would work.

So ultimately, I still dont have the solution. :)

Thank again
Brent


On 20/09/2011 22:23, Holger Parplies wrote:
> Hi,
>
> if we keep this on-list, there's a greater chance of someone with more
> knowledge of LVM being able to help you (though it really doesn't strike
> me as an LVM problem - more of an initrd problem involving LVM, though that
> might be splitting hairs).
>
> Brent Clark wrote on 20.09.2011 at 15:57:15 [Re: [linux-lvm] Debian 64bit get a "Volume vg0 not found" message]:
>> [...]
>> To answer your questions, I felt it would be best to take a few
>> screenshots. I really hope you dont mind, and you are still able and
>> willing to help.
>
> * The first screenshot shows the tail of a boot attempt, in particular:
>
>      Volume group "vg0" not found
>      Skipping volume group vg0
>    Unable to find LVM volume vg0/root
>      Volume group "vg0" not found
>      Skipping volume group vg0
>    Unable to find LVM volume vg0/swap
>    Gave up waiting for root device.  Common problems:
> [...]
>    ALERT!  /dev/mapper/vg0-root does not exist.  Dropping to a shell!
>
>    (which then, in fact, happens).
>
> * The second screenshot shows a 'vgdisplay' of vg0 from *a different system*
>    (apparently a live rescue CD or something similar). This is basically
>    meaningless. We know the VG exists. The question is why *the initrd used
>    to boot* doesn't find it. You could try investigating from the initrd
>    shell you end up in.
>
> * The third screenshot shows the grub stanza used for booting, apparently
>    at boot time and displayed by grub.
>
> All of this seems to be happening inside a virtual machine, if I interpret
> the window decoration in your screen shots correctly. I don't expect that to
> matter, but I'll mention it for the sake of completeness.
>
> Concerning the third screenshot, I don't think this matter has anything to do
> with grub. grub's job is to load the kernel and the initrd - apparently it can
> do so from RAID and LVM devices nowadays. In your case, /boot seems to reside
> on /dev/md0 (which works for me even without RAID support in grub - it simply
> reads one of the member devices of my RAID1 array; for other RAID levels,
> this obviously wouldn't work without special support ;-).
>
> Now it's up to the initrd to set up access to the root device, which could
> potentially be accessed over NFS, be part of a RAID, or - in your case - LVM
> VG, or need some special drivers (e.g. SCSI) that are not compiled into the
> kernel. For some reason, this does not work for you. Actually, I've seen
> exactly that same problem myself on a Debian etch system with root on LVM,
> where I tried to install the squeeze kernel (both the etch and lenny kernels
> find the root LV and mount it). I tried manually updating the initrd. For some
> reason, this didn't work (or rather, it didn't solve the problem). It wasn't
> that urgent for me, so I haven't looked into it any further until now, but I'm
> still interested in a solution, so if somebody has one (or a pointer in the
> right direction), I'd be grateful, too. Otherwise, I'll investigate once I find
> some time. I'd also be grateful for corrections of any misconceptions I
> might have.
>
> One additional data point: a clean squeeze installation with root on LVM
> works as expected, so [in my case] it's probably the combination of etch
> userland and squeeze kernel that causes problems, not the squeeze kernel per
> se.
>
> So, the question remains: which Debian distribution and which kernel are you
> using? Also, of what PVs does your VG consist? Assuming you are probably using
> RAID devices there, too, the initrd could potentially activate RAID and LVM
> in the wrong order or fail to activate RAID at all (it apparently *did* try to
> activate LVM).
>
> Hope some of that helps.
>
> Regards,
> Holger