Lvm – lvremove claims LV to be open

The following should work (adapt as necessary):

# cat /etc/udev/rules.d/99-custom.rules
ENV{DM_NAME}=="system-test", ACTION=="add|change", MODE="0664", OWNER="michael", GROUP="disk", PROGRAM="/bin/logger /dev/$env{DM_NAME} owner changed to michael", SYMLINK+="oracle-$env{DM_NAME}"

Then you should get the result:

# lvcreate -L 1G /dev/system -n test
# ls -al /dev/dm-9 /dev/oracle-system-test /dev/system/test /dev/mapper/system-test
brw-rw-r-- 1 michael disk 253, 9 2009-08-08 01:20 /dev/dm-9
brw-r----- 1 root    disk 253, 9 2009-08-08 01:20 /dev/mapper/system-test
lrwxrwxrwx 1 root    root      4 2009-08-08 01:20 /dev/oracle-system-test -> dm-9
lrwxrwxrwx 1 root    root     23 2009-08-08 01:20 /dev/system/test -> /dev/mapper/system-test

I wasn't able to figure out how to modify the actual device node created by LVM, but I was able to modify the device-mapper node. I then added a symlink for oracle to access it with which is a bit of a hack, but works.

(my earlier answer was a little rushed and untested. But I got really curious how to do it right :)

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
 }