Grub2 doesn't boot with the root volume snapshot on - it gets to this:
Waiting 10 seconds for device /dev/mapper/ ... ERROR: Unable to find root device You are being dropped to a recovery shell
If you type exit at the prompt the boot sequence occasionally resumes, or you can mount the /dev/mapper/... under / and type exit. But this is not a real solution, something needs to be fixed in mkinitcpio. Hint: "mount: /dev/mapper/myvg-mylv is already mounted or /new_root busy"
Also 'grub-mkconfig -o /boot/grub/grub.cfg' hangs when the root lvm snapshot is on :-(
dmeventd.service still hangs on shutdown with active snapshots (2018-13-01)
Seems to be a seven year old dispute between LVM2 and systemd over who should be responsible for fixing this. Since users aren't paying, there is little pressure to resolve this. —This unsigned comment is by Pswinslow (talk) 04:40, 14 January 2018. Please sign your posts with ~~~~!
Solution for automatic removal of snapshots with systemd unit (2018-12-11)
I am using the mk-lvm-snapshots unit file of this page. So I looked for a possibility to remove them automatically on shut-down. I had a lot of trouble with it, so maybe there are others out there with the same problem. Should I add a paragraph in the article with my solution? will_wisp (talk) 22:36, 12 November 2018 (UTC)