After upgrading to 4.4.0-59 yesterday I realized today that my zfs partitions were gone! Googling a bit suggested that [http://pastebin.com/BPFj1Ewj ] zfs-native 0.6.5.7 did not like (as in: compile with) the -59 kernel.

Sure enough, zfs is missing from the -59 kernel (check last 2 lines):

% dkms status

bbswitch, 0.7, 4.4.0-53-generic, x86_64: installed

bbswitch, 0.7, 4.4.0-57-generic, x86_64: installed

bbswitch, 0.7, 4.4.0-59-generic, x86_64: installed

nvidia-340, 340.98, 4.4.0-53-generic, x86_64: installed

nvidia-340, 340.98, 4.4.0-57-generic, x86_64: installed

nvidia-340, 340.98, 4.4.0-59-generic, x86_64: installed

spl, 0.6.5.7, 4.4.0-53-generic, x86_64: installed

spl, 0.6.5.7, 4.4.0-57-generic, x86_64: installed

spl, 0.6.5.7, 4.4.0-59-generic, x86_64: installed

virtualbox, 4.3.36, 4.4.0-53-generic, x86_64: installed

virtualbox, 4.3.36, 4.4.0-57-generic, x86_64: installed

virtualbox, 4.3.36, 4.4.0-59-generic, x86_64: installed

zfs, 0.6.5.7, 4.4.0-53-generic, x86_64: installed

zfs, 0.6.5.7, 4.4.0-57-generic, x86_64: installed

Ok, what to do? Reboot under the previously known good kernel (-57)!

After rebooting, sure I can access my zpool, but my partitions are not mounted. To confuse matters even more,

zpool status

suggests I upgrade my pool:

% sudo zpool status

  pool: tank

 state: ONLINE

status: Some supported features are not enabled on the pool. The pool can

        still be used, but some features are unavailable.

action: Enable all features using 'zpool upgrade'. Once this is done,

        the pool may no longer be accessible by software that does not support

        the features. See zpool-features(5) for details.

  scan: none requested

config:



        NAME                                                STATE     READ WRITE CKSUM

        tank                                                ONLINE       0     0     0

          mirror-0                                          ONLINE       0     0     0

            ata-ST4000DM000-1F2168_S3014GKE-part4           ONLINE       0     0     0

            ata-WDC_WD40PURX-64GVNY0_WD-WCC4E5UZUFFD-part4  ONLINE       0     0     0



errors: No known data errors

Dare I do that? Or, did something get messed up during the failed update to 4.4.0-59? I have installed zfs via

apt-get install ubuntu-zfs

and do not feel brave enough to try to compile and install the zfs module myself. For now, I just want my zfs partitions back!

Update: I have posted the solution that worked below. It might be against askubuntu rules, but I wanted to have this info out as soon as possible if someone else were to run into the same problem.