I had repeatable disk corruption due to this issue, so I think fixing it should be given a higher priority! I experienced this issue with Ubuntu 22.04 (and probably 20.04) on an encrypted LVM installation:
systemd-shutdown[1]: Could not detach DM /dm/dm-9: Device or resource busy systemd-shutdown[1]: Could not detach DM /dm/dm-7: Device or resource busy systemd-shutdown[1]: Could not detach DM /dm/dm-11: Device or resource busy systemd-shutdown[1]: Could not detach DM /dm/dm-10: Device or resource busy systemd-shutdown[1]: Could not detach DM /dm/dm-1: Device or resource busy systemd-shutdown[1]: Could not detach DM /dm/dm-0: Device or resource busy systemd-shutdown[1]: Failed to finalize DM devices, ignoring. I found the easiest way to check for these messages is to shutdown using: sudo systemctl halt For some years I've tried to configure LVM to use an NVMe drive as a cache for the / and /home partitions on my main drive, but I always ended-up getting severe corruption after some time. Recently I realised that after booting, lvmcache would spend a long time copying my whole NVMe cache back to the main drive (and slow everything down until that finished), as "sudo lvs -a" showed that "Cpy%Sync" was non-zero but dropping. I read that: "The most likely cause is your system was not shutdown cleanly so dm- cache has no choice but to assume all blocks are dirty and need writing back." Once I realised the above "Device or resource busy" error messages were probably related to this problem, I followed Boulardii's earlier tip here about installing dracut-core. Since then I no-longer get those error messages - and fingers crossed I haven't had any corruption since re-enabling LVM's caching. In case it helps, my /etc/crypttab file looks roughly like this: sdz5_crypt UUID=... /dev/disk/by-label/DRIVENAME:/filename.key luks,discard,noauto,keyscript=passdev nvme0n1_crypt UUID=... /dev/disk/by-label/DRIVENAME:/filename.key luks,discard,noauto,keyscript=passdev (I did try adding ,x-initrd.attach but that didn't help.) And maybe helpful for others: Some time ago I switched from Ext4 to Btrfs, because the disk corruption spread badly before Ext4 noticed (and by that time it was way too late to repair it - I had to format & restore). With a correctly configured Btfs (-mdup), it stops the system at the first sign of corruption (easily repaired), and that allowed me to try various ways to fix the problem - which were all unsuccessful until now. Also beware that converting an Ext4 partition to Btrfs results in it using -msingle which is extremely fragile, so make sure to convert it to -mdup ASAP. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1905166 Title: systemd-shutdown cannot detach DM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/finalrd/+bug/1905166/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
