Bug#555958: Activation of lvm snapshots

[Ian Jackson]

Looking at this bug the problem, as described by the submitter, seems
to be this:

root(ian)@liberator:~> lvcreate -s -L 1G -n t /dev/vg-liberator/schroot-wheezy 
  Logical volume "t" created
root(ian)@liberator:~> lvs
  LV             VG           Attr   LSize  Origin         Snap%  Move Log Copy%  Convert
  lv-root        vg-liberator -wi-ao 25.00g
  lv-swap        vg-liberator -wi-ao  5.00g
  lv-ubuntu      vg-liberator -wi-ao  5.00g
  lv-volt        vg-liberator -wi-ao 40.00g
  schroot-wheezy vg-liberator owi-a- 10.00g
  t              vg-liberator swi-a-  1.00g schroot-wheezy   0.00
root(ian)@liberator:~> lvchange -a n /dev/vg-liberator/schroot-wheezy
root(ian)@liberator:~> lvchange -a n /dev/vg-liberator/t
  Can't change snapshot logical volume "t"
root(ian)@liberator:~> lvs
  LV             VG           Attr   LSize  Origin         Snap%  Move Log Copy%  Convert
  lv-root        vg-liberator -wi-ao 25.00g
  lv-swap        vg-liberator -wi-ao  5.00g
  lv-ubuntu      vg-liberator -wi-ao  5.00g
  lv-volt        vg-liberator -wi-ao 40.00g
  schroot-wheezy vg-liberator owi--- 10.00g
  t              vg-liberator swi---  1.00g schroot-wheezy
root(ian)@liberator:~> lvchange -a y /dev/vg-liberator/t
  Can't change snapshot logical volume "t"
root(ian)@liberator:~>

I think
   lvchange -a y <some snapshot lv>
should activate the underlying lv if that's necessary.  Or at the very
least there should be some way to ask lvchange/vgchange to do so.

So the real bug is in the lvm tools themselves, not in the initramfs
scripts.

Ian.