Sorry for the late reply, I didn't get any notifications of your response. After I reported this issue there were a couple of updates to ZFS. This problem never occurred again, and there were several updates that redid initramfs, kernel, etc..., with the pool being imported and mounted. Didn't have to mark it for no cachefile either.
Looks to me this is fixed. * zfsutils-linux-0.6.5.6-0ubuntu14 * Linux erebus 4.4.0-36-generic #55-Ubuntu SMP Thu Aug 11 18:01:55 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux -- 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/1624844 Title: Ubuntu 16.04 breaks boot with wrong zpool.cache Status in zfs-linux package in Ubuntu: Incomplete Bug description: Having just upgraded Ubuntu 16.04, and seeing systemd updates, I rebooted the machine, but it failed to start, entering emergency mode. Relevant piece of info was this: * Failed to start Import ZFS pools by cache file. * Started Mount ZFS filesystems ** A start job is running for dev-disk.... and then it enters emergency mode. Now, the only ZFS pool I have is a backup USB HDD which is constantly attached, and the pool is on a LUKS provider, meaning you won't see it until the provider is unlocked. My guess is that the latest update, having triggered initramfs rebuild, wrote the zpool.cache file with that state, and it shouldn't have. This is totally wrong, as zpool cache should not be built like this as it PREVENTS you from having external pools that might not be available on boot. I also have no idea why it happened now because I've been having this setup (external backup zfs pool on a LUKS provider) since 16.04 came out and never had a problem until now. Removing the /etc/zfs/zpool.cache allowed the system to reboot fine. # lsb_release -rd Description: Ubuntu 16.04.1 LTS Release: 16.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/zfs-linux/+bug/1624844/+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
