Comment 14 for bug 1739761

We really probably should make it so that the modprobe is not fatal.
Obviously if you're trying to install zfs it would be fatal, but otherwise
we should go on.

I just went to verify if we have zfs in initramfs. Heres what I found:
$ sstream-mirror --max=1 --progress \
    http://images.maas.io/ephemeral-v3/daily/streams/v1/index.json \
    out.d ftype=boot-initrd arch=amd64 \
    "release~(precise|trusty|xenial|artful|bionic)"
$ for f in $(find out.d/*/amd64 -type f | sort); do
   lsinitramfs "$f" | grep -q "zfs.ko$" && found="YES" || found="NO "
   echo "$found ${f#out.d/}"; done
NO precise/amd64/20170424/hwe-p/generic/boot-initrd
NO precise/amd64/20170424/hwe-q/generic/boot-initrd
NO precise/amd64/20170424/hwe-r/generic/boot-initrd
NO precise/amd64/20170424/hwe-s/generic/boot-initrd
NO precise/amd64/20170424/hwe-t/generic/boot-initrd
NO trusty/amd64/20180419/hwe-t/generic/boot-initrd
NO trusty/amd64/20180419/hwe-u/generic/boot-initrd
NO trusty/amd64/20180419/hwe-v/generic/boot-initrd
NO trusty/amd64/20180419/hwe-w/generic/boot-initrd
NO trusty/amd64/20180419/hwe-x/generic/boot-initrd
NO trusty/amd64/20180419/hwe-x/lowlatency/boot-initrd
YES artful/amd64/20180425/ga-17.10/generic/boot-initrd
YES artful/amd64/20180425/ga-17.10/lowlatency/boot-initrd
YES bionic/amd64/20180426.2/ga-18.04/generic/boot-initrd
YES bionic/amd64/20180426.2/ga-18.04/lowlatency/boot-initrd
YES xenial/amd64/20180424/ga-16.04/generic/boot-initrd
YES xenial/amd64/20180424/ga-16.04/lowlatency/boot-initrd
YES xenial/amd64/20180424/hwe-16.04-edge/generic/boot-initrd
YES xenial/amd64/20180424/hwe-16.04-edge/lowlatency/boot-initrd
YES xenial/amd64/20180424/hwe-16.04/generic/boot-initrd
YES xenial/amd64/20180424/hwe-16.04/lowlatency/boot-initrd

The summary is all current initramfs for v3 images have zfs except precise and trusty.

modprobe could fail for another reason. but it looks like at least 'zfs.ko' is present.