Error: Failed preparing container for start: Failed to run: zfs mount filesystem already mounted

[tomp (Thomas Parrott)]

What about inside the mount namespace, as mentioned here

Error removing LVM logical volume

Yeah, this issue has mostly been seen on ZFS, likely because we have far more ZFS users than LVM. Our best guess is that it has to do with a system having running containers, combined with an update to some of the core snaps and combined with a LXD snap update, some combination of this then results in a mount namespace configuration which our reshuffling tool can’t deal with, resulting in the error we can see in your journal. Unfortunately fixing this properly will require us being able to rep…