It might be also a result of the bogus mount.zfs, which requires POSIX incorrect arguments but honors POSIXLY_CORRECT env var!
Had a similar zfs mount order problem with a rpool/local/home/{A,B,C} tree (was created using -p option) ... -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to zfs-linux in Ubuntu. https://bugs.launchpad.net/bugs/1694090 Title: ZoL: wrong import order prevents boot Status in zfs-linux package in Ubuntu: Incomplete Bug description: I've the following zfs: # zfs list -r rpool/VARSHARE NAME USED AVAIL REFER MOUNTPOINT rpool/VARSHARE 114K 165G 30K /var/share rpool/VARSHARE/lxc 84K 165G 19K /var/share/lxc rpool/VARSHARE/lxc/xenial 65K 165G 19K /var/share/lxc/xenial rpool/VARSHARE/lxc/xenial/pkg 19K 165G 19K /var/share/lxc/xenial/pkg rpool/VARSHARE/lxc/xenial/rootfs-amd64 27K 165G 27K /var/share/lxc/xenial/rootfs-amd64 On boot, we see Starting Mount ZFS filesystems... [FAILED] Failed to start Mount ZFS filesystems. See 'systemctl status zfs-mount.service' for details. Welcome to emergPress Enter for maintenance (or press Control-D to continue): # df -h /var/share rpool/VARSHARE/lxc 165G 0 165G 0% /var/share/lxc rpool/VARSHARE/lxc/xenial 165G 0 165G 0% /var/share/lxc/xenial rpool/VARSHARE/lxc/xenial/pkg 165G 0 165G 0% /var/share/lxc/xenial/pkg rpool/VARSHARE/lxc/xenial/rootfs-amd64 165G 0 165G 0% /var/share/lxc/xenial/rootfs-amd64 Obviously rpool/VARSHARE - the parent of rpool/VARSHARE/lxc - was not mounted, even so canmount property is for all set to on, rpool/VARSHARE's mountpoint to /var/share and rpool/VARSHARE/lxc children inherit their mountpoint. # systemctl status zfs-mount.service ● zfs-mount.service - Mount ZFS filesystems Loaded: loaded (/lib/systemd/system/zfs-mount.service; static; vendor preset: enabled) Active: failed (Result: exit-code) since Sun 2017-05-28 04:51:46 CEST; 13min ago Process: 6935 ExecStart=/sbin/zfs mount -a (code=exited, status=1/FAILURE) Main PID: 6935 (code=exited, status=1/FAILURE) May 28 04:51:45 ares systemd[1]: Starting Mount ZFS filesystems... May 28 04:51:45 ares zfs[6935]: cannot mount '/var/share': directory is not empty May 28 04:51:46 ares systemd[1]: zfs-mount.service: Main process exited, code=exited, status=1/FAILURE May 28 04:51:46 ares systemd[1]: Failed to start Mount ZFS filesystems. May 28 04:51:46 ares systemd[1]: zfs-mount.service: Unit entered failed state. May 28 04:51:46 ares systemd[1]: zfs-mount.service: Failed with result 'exit-code'. So 'zfs mount ...' seems to be severely buggy. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/zfs-linux/+bug/1694090/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp