Logical volumes are inactive at boot time

So I managed to solve this eventually. There is a problem (bug) with detecting logical volumes, which is some sort of race condition (maybe in my case regarding the fact that this happens inside KVM). This is covered in the following discussion. In my particular case (Debian Squeeze ) the solution is as follows:

• backup the script /usr/share/initramfs-tools/scripts/local-top/lvm2
• apply the patch from mentioned bug report
• run update-initramfs -u

This helped me, hope it'll help others (strangely, this is not part of mainstream yet).

Link to patch: _http://bugs.debian.org/cgi-bin/bugreport.cgi?msg=10;filename=lvm2_wait-lvm.patch;att=1;bug=568838

Below is a copy for posterity.

--- /usr/share/initramfs-tools/scripts/local-top/lvm2 2009-08-17 19:28:09.000000000 +0200
+++ /usr/share/initramfs-tools/scripts/local-top/lvm2 2010-02-19 23:22:14.000000000 +0100
@@ -45,12 +45,30 @@

  eval $(dmsetup splitname --nameprefixes --noheadings --rows "$dev")

- if [ "$DM_VG_NAME" ] && [ "$DM_LV_NAME" ]; then
-   lvm lvchange -aly --ignorelockingfailure "$DM_VG_NAME/$DM_LV_NAME"
-   rc=$?
-   if [ $rc = 5 ]; then
-     echo "Unable to find LVM volume $DM_VG_NAME/$DM_LV_NAME"
-   fi
+ # Make sure that we have non-empty volume group and logical volume
+ if [ -z "$DM_VG_NAME" ] || [ -z "$DM_LV_NAME" ]; then
+   return 1
+ fi
+
+ # If the logical volume hasn't shown up yet, give it a little while
+ # to deal with LVM on removable devices (inspired from scripts/local)
+ fulldev="/dev/$DM_VG_NAME/$DM_LV_NAME"
+ if [ -z "`lvm lvscan -a --ignorelockingfailure |grep $fulldev`" ]; then
+   # Use default root delay
+   slumber=$(( ${ROOTDELAY:-180} * 10 ))
+
+   while [ -z "`lvm lvscan -a --ignorelockingfailure |grep $fulldev`" ]; do
+     /bin/sleep 0.1
+     slumber=$(( ${slumber} - 1 ))
+     [ ${slumber} -gt 0 ] || break
+   done
+ fi
+
+ # Activate logical volume
+ lvm lvchange -aly --ignorelockingfailure "$DM_VG_NAME/$DM_LV_NAME"
+ rc=$?
+ if [ $rc = 5 ]; then
+   echo "Unable to find LVM volume $DM_VG_NAME/$DM_LV_NAME"
  fi
 }

Create a startup script in /etc/init.d/lvm containing the following:

#!/bin/sh

case "$1" in
 start)
    /sbin/vgscan
    /sbin/vgchange -ay
    ;;
  stop)
    /sbin/vgchange -an
    ;;
  restart|force-reload)
    ;;
esac

exit 0

Then execute the commands:

chmod 0755 /etc/init.d/lvm
update-rc.d lvm start 26 S . stop 82 1 .

Should do the trick for Debian systems.