Comment 1 for bug 147216

Basically I suspect that the udev events that are supposed to be getting triggered duing the boot process in the initramfs are not getting triggered, hence a vgscan is never done. My guess is based on the contents of :

rudd-o@karen:/etc/udev/rules.d$ cat 85-lvm2.rules
# This file causes block devices with LVM signatures to be automatically
# added to their volume group.
# See udev(8) for syntax

SUBSYSTEM=="block", ACTION=="add|change", ENV{ID_FS_TYPE}=="lvm*|LVM*", \
        RUN+="watershed sh -c '/sbin/lvm vgscan; /sbin/lvm vgchange -a y'"

here's the output of pvdisplay

root@karen:/etc/udev/rules.d# pvdisplay
  --- Physical volume ---
  PV Name /dev/md0
  VG Name vg0
  PV Size 362,49 GB / not usable 1,25 MB
  Allocatable yes (but full)
  PE Size (KByte) 4096
  Total PE 92797
  Free PE 0
  Allocated PE 92797
  PV UUID OoPCI9-1Lj3-0eU7-3dbE-dLIz-0AKz-sjcJMz

  --- Physical volume ---
  PV Name /dev/md1
  VG Name vg0
  PV Size 9,54 GB / not usable 1,81 MB
  Allocatable yes (but full)
  PE Size (KByte) 4096
  Total PE 2443
  Free PE 0
  Allocated PE 2443
  PV UUID 5SndoF-iOPs-kGpy-WQzl-S0BJ-wydK-PSaOC6