My Laptop is configured as dual boot system with Ubuntu 14.04 (and windows 8.1). Lately I replaced the dedicated root and swap partitions with a lvm2 partition (VG (Volume Group) LinuxBereich) containing LVs (Logical Volume) LinuxSwap, LinuxRoot, and LinuxHome. There are copies of root, and home in thin pool LVs RootArea, and HomeArea named Linux_Root, and Linux_Boot.
- 3.13.0-62-generic starts or resumes correctly, from non pool LV.
- 3.13.0-63-generic doesn't find the root partition and drops to the busybox shell. After activating LVs LinuxSwap, LinuxRoot, and LinuxHome with lvm, startup proceeds without further problems.
- Neither version (62/63) starts from LV in thin pool. Attempting:
lvm lvchange -ay LinuxBereich/Linux_Root
(or Linux_Home, RootArea, HomeArea)
from the busybox shell, results in:
/sbin/modprobe failed: 1
Cannot read thin-pool target version.
Can't process LV Linux_Root: thin-pool target support missing from kernel ?
It would be nice if the LVs would be activated automatically in 3.13.0-63-generic.
It would be even better if the system started from thin-pool.
Any ideas are welcome. Maybe I need some more patience.
Yours
Wolfgang
Solutions:
- 3.13.0-63-generic (and 3.13.0-65-generic) starts from LV now without problem.
Cause was a missing file in /boot/initrd.img-3.13.0-63-generic that is present in /boot/initrd.img-3.13.0-63-generic:
-rw-r--r-- 1 root root 272 May 4 2012 lib/udev/rules.d/85-lvm2.rules
Checking for such a file yielded:
ls -l /lib/udev/rules.d/85-lvm*
-rw-r--r-- 1 root root 272 May 4 2012 /lib/udev/rules.d/85-lvm2.rules.drblsave
so the file was present, but renamed.
cp -p /lib/udev/rules.d/85-lvm2.rules.drblsave /lib/udev/rules.d/85-lvm2.rules
and
update-initramfs -u
did the trick.
For obtaining a sorted table of content of the initrd.img:
for n in 62 63 65;do zcat /boot/initrd.img-3.13.0-$n-generic|cpio -itv|sort -k9>$n.lst;done
Without modification time and kernel version
for n in 62 63 65;do sed 's/3.13.0-6./3.13.0-6?/g' $n.lst|cut -c 1-42,56->$n.lsu;done
No start from thin pool LV, because of no kernel support. This is weird, because the running system is able to handle thin volumes.
lsmod |grep -ie dm_thin_pool -e dm_persistent_data -e dm_bio_prison -e dm_bufio -e libcrc32c dm_thin_pool 46897 7 dm_persistent_data 61675 1 dm_thin_pool dm_bufio 27539 1 dm_persistent_data dm_bio_prison 15501 1 dm_thin_pool libcrc32c 12644 1 dm_persistent_data for n in dm_thin_pool dm_persistent_data dm_bio_prison dm_bufio libcrc32c;do modinfo $n;done|grep filename:|sort -u filename: /lib/modules/3.13.0-65-generic/kernel/drivers/md/dm-bio-prison.ko filename: /lib/modules/3.13.0-65-generic/kernel/drivers/md/dm-bufio.ko filename: /lib/modules/3.13.0-65-generic/kernel/drivers/md/dm-thin-pool.ko filename: /lib/modules/3.13.0-65-generic/kernel/drivers/md/persistent-data/dm-persistent-data.ko filename: /lib/modules/3.13.0-65-generic/kernel/lib/libcrc32c.ko
So a file /etc/initramfs-tools/hooks/lvm2thin was created:
#!/bin/sh
PREREQ=""
prereqs()
{
echo "$PREREQ"
}
case $1 in
prereqs)
prereqs
exit 0
;;
esac
. /usr/share/initramfs-tools/hook-functions
# Begin real processing below this line
copy_exec /lib/modules/${version}/kernel/drivers/md/dm-thin-pool.ko
copy_exec /lib/modules/${version}/kernel/drivers/md/dm-bio-prison.ko
copy_exec /lib/modules/${version}/kernel/drivers/md/dm-bufio.ko
copy_exec /lib/modules/${version}/kernel/drivers/md/persistent-data/dm-persistent-data.ko
Set proper permissions.
chmod 755 /etc/initramfs-tools/hooks/lvm2thin
ls -l /etc/initramfs-tools/hooks/lvm2thin
-rwxr-xr-x 1 root root 583 Okt 8 18:16 /etc/initramfs-tools/hooks/lvm2thin
and again
update-initramfs -u
done.
