[linux-lvm] No device found for PV but is actually fine

[Michal Svoboda]

Marian Csontos wrote:
> Michal(-e), I suggest modifying global_filter to accept only the
> devices you want in the VG.

Hi,

I've tried playing with filter and global_filter in lvm.conf, but it did
not help - as if the conf file was ignored. I tried blacklisting and
whitelisting. Does something need to be restarted/rebooted for these
settings to take effect?

I then did some more experiments and eventually solved the issue.

First I tried pvscan --cache /dev/md0, at which point md0 was "accepted"
as existing PV, and the "system" VG would show up in vgdisplay. I was
even able to resize one of the LVs. However, after running pvscan --cache
with no extra agruments, I would receive the duplicate PV errors as in
previous e-mail and the "system" VG would disappear from vgdisplay. :-o

Finally I solved the issue by changing initcpio hook from "mdadm_udev"
to "mdadm". This is arch-linux specific thing that changes stuff that is
exported to the initial ramdisk used for boot. User-wise, that change
would stop using udev auto-magic for assembling md arrays, but use
/etc/mdadm.conf directly instead. I don't know the implementation details.

After that I receive *no more errors* about either missing or duplicate
PV and all VGs/LVs are displayed by the respective display commands. So
for me issue is solved but if anyone wants to get to the bottom I am
open to do some more experiments.


Michal Svoboda