The pertinent part of the log shows that the mount failed because /tank directory was not empty which is expected behaviour.
invoke-rc.d: initscript zfs-mount, action "start" failed. [0;1;31m●[0m zfs-mount.service - Mount ZFS filesystems Loaded: loaded (/lib/systemd/system/zfs-mount.service; static; vendor preset: enabled) Active: [0;1;31mfailed[0m (Result: exit-code) since ven 2017-04-07 07:08:52 CEST; 11ms ago Process: 29776 ExecStart=/sbin/zfs mount -a [0;1;31m(code=exited, status=1/FAILURE)[0m Main PID: 29776 (code=exited, status=1/FAILURE) apr 07 07:08:51 mediaserver systemd[1]: Starting Mount ZFS filesystems... apr 07 07:08:52 mediaserver zfs[29776]: cannot mount '/tank': directory is n...y apr 07 07:08:52 mediaserver systemd[1]: [0;1;39mzfs-mount.service: Main process exit...E[0m apr 07 07:08:52 mediaserver systemd[1]: [0;1;31mFailed to start Mount ZFS filesystems.[0m apr 07 07:08:52 mediaserver systemd[1]: [0;1;39mzfs-mount.service: Unit entered fail....[0m apr 07 07:08:52 mediaserver systemd[1]: [0;1;39mzfs-mount.service: Failed with resul....[0m Hint: Some lines were ellipsized, use -l to show in full. dpkg: error processing package zfsutils-linux (--configure): subprocess installed post-installation script returned error exit status 1 ** Changed in: zfs-linux (Ubuntu) Status: New => Won't Fix ** Changed in: zfs-linux (Ubuntu) Importance: Undecided => Medium ** Changed in: zfs-linux (Ubuntu) Assignee: (unassigned) => Colin Ian King (colin-king) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1680699 Title: package zfsutils-linux 0.6.5.6-0ubuntu16 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/zfs-linux/+bug/1680699/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs