Arch Linux

Yes, please add thin provisioning support to the LVM2 tools. The Linux Kernel provides the according device mapper targets since Version 3.2 [1].

[1] https://github.com/jthornber/linux-2.6/blob/thin-stable/Documentation/device-mapper/thin-provisioning.txt

I fail to find any release tarballs on the thin provisioning tools, or a homepage, or any overview of releases for that matter.

There is no need to use external tools for using thin provisioned lvm pools. Just using

./configure --with-thin=internal --enable-dmeventd --enable-cmdlib

is enough to be able to create and delete thin provisioned pools and volumes, and take snapshots of these. Of course, other needed configure flags should be added as well.

I have created a patch (lvm2.udiff) for LVM2 package, and created the thin-provisioning-tools PKGBUILD to include the thin_check binaries (Edit: Uploaded to AUR https://aur.archlinux.org/packages/thin-provisioning-tools/).

I have tested this on an ArchISO CD, creating a Thinly Provisioned root partition, and booting from it.

Changes are:
PKGBUILD:
- Increment Package Release
- Add thin-provisioning-tools to depends and makedepends
- Add --with-thin=internal to ./configure parameters
- Update SHA1 Sum for lvm2_install
lvm2_install (for mkinitcpio):
- Add dm-thin-pool module
- Add thin_check binary

There is is releases tarball on github: https://github.com/jthornber/thin-provisioning-tools/releases
We could use that for the package. I am working on updating lvm2. I could implement this (I don't plan using this feature though) if there are no objections.

lvm2 2.02.102-1 in [testing] has thin-provisioning support.

As shown below, the specific lvm thin provisionning modules are not installed in the initramfs when running mkinitramfs:

$ cat /usr/lib/initcpio/install/lvm2 |grep mod
local mod
for mod in dm-mod dm-snapshot dm-mirror dm-cache dm-cache-mq; do
add_module "$mod"

The module dm-thin-pool is missing in this list, which make archlinux unable to mount a thin provisionned lvm root system. I tested the change and it allowed to detect correctly the thin provisionned volume and to boot.

As sugested by the author of the patch, the binary thin_check should also been added to the initramfs.

Spent a bunch of time on this, before running across this page.

lvm2_install never got "dm-thin-pool" added to the for mod in line, nor did it get the 'add_binary "/usr/bin/thin_check"' line.

Adding those and re-running mkinitcpio lets me boot.

Hello,

The package has been updated but it is still not fixed.

Todays update added the dm-thin-pool module to the initramrd.

Unfortunately there are some parts missing, because my system is unable to start the lvm2-pvscan@.service unit (I use sd-lvm2, btw):

May 08 10:40:37 localhost systemd[1]: Starting LVM2 PV scan on device 8:2...
May 08 10:40:38 localhost lvm[123]: /usr/bin/thin_check: execvp failed: No such file or directory
May 08 10:40:38 localhost lvm[123]: Check of pool VG/VM-Pool failed (status:2). Manual repair required!
May 08 10:40:38 localhost lvm[123]: /usr/bin/thin_check: execvp failed: No such file or directory
May 08 10:40:38 localhost lvm[123]: /usr/bin/thin_check: execvp failed: No such file or directory
May 08 10:42:08 localhost systemd[1]: lvm2-pvscan@8:2.service: State 'stop-sigterm' timed out. Killing.
May 08 10:42:08 localhost systemd[1]: lvm2-pvscan@8:2.service: Main process exited, code=killed, status=9/KILL

I tried adding "add_binary /usr/bin/thin_check" to /usr/lib/initcpio/install/sd-lvm2 but the unit is still failing:
May 08 10:59:22 localhost systemd[1]: Starting LVM2 PV scan on device 8:2...
May 08 10:59:24 localhost lvm[125]: Child 175 exited abnormally
May 08 10:59:24 localhost lvm[125]: Check of pool VG/VM-Pool failed (status:-1). Manual repair required!
May 08 11:00:54 localhost systemd[1]: lvm2-pvscan@8:2.service: State 'stop-sigterm' timed out. Killing.
May 08 11:00:54 localhost systemd[1]: lvm2-pvscan@8:2.service: Main process exited, code=killed, status=9/KILL

My root partition is not located on a thin-provising volume, but other filesystems are. The system is able to boot and only some units fail. After restarting the unit lvm2-pvscan@8:2 manually everything works fine. I don’t know the cause of the exact problem, but downgrading to lvm2-2.02.149-1 works for me.