Hi,
i don’t know why ZFS is not available on my Ubuntu 18.04. I spent a lot of time reinstalling LXD and zfsutils-linux, but when I run lxd init, there is no still ZFS available to choose.
tprus@bla:~$ whereis zfs
zfs: /usr/lib/x86_64-linux-gnu/zfs /sbin/zfs /etc/zfs /usr/share/man/man8/zfs.8.gz
tprus@bla:~$ sudo /sbin/modprobe zfs
modprobe: FATAL: Module zfs not found in directory /lib/modules/4.18.0-041800rc5-generic
Any advise, please 
Hi!
ZFS (the kernel module) should be available in the stock Linux kernels of Ubuntu, including 18.04 that your are trying. If you have booted with some other kernel, most likely you do not have ZFS.
You are running kernel 4.18.0-041800rc5-generic, which does not look like a stock kernel.
I suggest to either switch back to the stock kernel (4.15 for Ubuntu 18.04), or switch forward to the latest kernel according to https://wiki.ubuntu.com/Kernel/LTSEnablementStack (Linux 5.3).
Note that the package zfsutils-linux is just the client package for ZFS. If you are using the snap package of LXD, then zfsutils-linux is not required. If you are using the deb package of LXD, then it is required.
I suggest to switch to Linux 5.3 (new, fresh, and cool), and to LXD 3.22 (snap package).
Thanks a lot, it works!
sudo apt install --install-recommends linux-generic-hwe-18.04 xserver-xorg-hwe-18.04