grub-probe warning when using root on top of extended volume group

[Gunnar Thielebein]

This error message comes up when using update-grub. It is reproducable 100% the time when you extend a volume group, inside a lukscrypted physical volume.

1. # vgextend ubuntu-vg <yournewpv>

2. # update-grub
Generating grub.cfg ...
/usr/sbin/grub-probe: warning: Couldn't find physical volume `pv0'. Some modules may be missing from core image..
Found linux image: /boot/vmlinuz-3.11.0-12-generic
Found initrd image: /boot/initrd.img-3.11.0-12-generic
/usr/sbin/grub-probe: warning: Couldn't find physical volume `pv0'. Some modules may be missing from core image..
Adding boot menu entry for EFI firmware configuration
done

usr/sbin/grub-probe: warning: Couldn't find physical volume `pv0'. Some modules may be missing from core image

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=13.10
DISTRIB_CODENAME=saucy
DISTRIB_DESCRIPTION="Ubuntu 13.10"

[Maarten Bezemer (veger)]

I have the same problem with my extended LVM volume groups.

https://bbs.archlinux.org/viewtopic.php?pid=1289321#p1289321 describes how to trigger this bug and provides some more information

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Phillip Susi (psusi)]

grub does not understand luks, therefore it can not find the pv.