[Mageia-dev] System doen't boot with LVM

[Colin Guthrie]

'Twas brillig, and Olivier Thauvin at 18/02/13 11:19 did gyre and gimble:
> I rebooted my laptop this morning and it failed to boot: unable to find
> my / under lvm.

Freshly updated cauldron booted fine for me this morning under LVM.

> I did try to do a fresh cauldron result but got same result.

Apparently there are some issues doing an LVM install at present:
https://bugs.mageia.org/show_bug.cgi?id=9032

Likely in some capacity an issue with lvm+udev (the linked bugs are
likely not the same cause).

> Dracut gi a shell, It seems 'lvm vgmknodes' has no effect (the swap lv
> did existed already).

In the dracut shell, what does /etc/cmdline.d/lvm.conf say? It should
contain enough info to brink up both the root and the swap lvm.

Note that the swap lvm is included thanks to the file
51-mageia-resume.conf (to handle the resume= case where swap is on LVM),
but the root FS detection is built into dracut, so if it's entry is
missing in the cmdline.d file then dracut itself is where the bug lies.


Which version of dracut did you use to create the initrd used here? If
it was dracut-025.1 then I think this is understandable as there was a
bug related to something similar relating to encrypted filesystems (it
didn't affect me here with pure LVM (no crypt), so it may not be the
issue you have) If it's still a problem with dracut-025.3 then I'll need
to look further.

As mentioned, problem fixed seemed to manifest itself more with the fact
that the encryption module wasn't included, but if you have an encrypted
root (or the LVM is on an encrypted volume) then I can see this causing
problems (due to not detecting the encrypted volume, it won't then
traverse it to find any slaves needed for it and thus never get to the
LVM parent) and the 025.3 dracut should fix it (at least in theory, tho'
I would not rule out any other problems in this regard!

So some more info about when the initrd was generated and when the
latest dracut version was installed would be useful to debug this
further. Also a description of your disk layout would be good too allow
me to create a similar setup for debugging.

Cheers :)

Col




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Colin Guthrie
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http://colin.guthr.ie/

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