LVM problem

[Ben Scott]

On Dec 14, 2007 5:51 PM, Dan Coutu <coutu at snowy-owl.com> wrote:
>>   The second message, about the VG being successfully extended,
>> indicates the PV was successfully added to the VG.  Then you blew it
>> away with the mkfs.  ;-)
>
> Exactly. I had never seen any message like that when doing LVM things
> and it threw me off. I figured it was an error of some sort and that I
> had to take some other action. Feh.

  Well, it was an error of some sort.  LVM has no way of knowing what
you have on your devices, and maybe you *did* expect that device to
have something LVMish on it, so it's warning you that it couldn't read
it.

  If you want, there's some place in some config file you can use to
explicitly declare what devices you want LVM to pay attention to.  But
then you'll have to remember to update the config file when you add
new devices.  Pick your poison.  :)

>> You probably need to first do a vgreduce to remove the (wrecked) PV
>> from the VG.
>
> Yeah, the Red Hat support person suggested that. Only it doesn't work.
> The vgreduce that is. It gripes about the unknown uuid.

  Hmmm.  I wonder if you got as far as extending an LV (i.e., having
an LV claim space on the troubled PV) before it got wrecked.  That
would likely mean you've corrupted the LV, which I'm sure will make
you sad.

  Check the output of "pvdisplay -v", "vgdisplay -v", and "lvdisplay
-v" to see detailed information about all known PVs, VGs, and LVs,
respectively.  See if you can figure out what LVM thinks is going on.
In particular, you should be interested in what PVs make up your
LV(s), and where the wrecked PV is being referenced (if anywhere).  If
that doesn't shed any immediate light on things, post the output of
those commands so we can take a look.

-- Ben