Comment 3 for bug 1422153

It comes with the zfs kernel modules. zfs is not part of mainstream ubuntu due to license incompatibilities.

/usr/bin/add-apt-repository ppa:zfs-native/trusty

packages zfs-dkms zfsutils

Even if ignoring details of zfs: I have booted the machine with nosplash to see the boot process messages. Opening these two encrypted disks happens very late, almost at the end of boot message. Which means that - beyond the zfs problem - regular services and daemons would fail to start if they had to access these disks instead of running from the boot device.

Formerly I had my machines configured to use raid disks with dmsetup, encrypt the md-device, put a lvm inside and have several logical partitions. This always worked since the initramfs boot code always decrypts this device early, because it contains the root partition.

The problem occured when I dropped raid and lvm, and put my data partitions on completely different disks which are neither root partions, nor resume partitions. Then the cryptdisk does not put them in the cryptroot list contained in the initramfs to be opened before pivoting the root file system and entering the real init.

This is not a problem if these partitions are not used for any service or daemon. If they are just there to be used e.g. for users logging in, this is no problem, since these disks are ready when login prompts appear.

But since zfs is started similar to any daemon on the system (and not through fstab), the problem occurs.