From the install log you can see that we install grub2 at 2.02~beta2-36ubuntu3.17.
..
Unpacking grub2-common (2.02~beta2-36ubuntu3.17)
..
'dpkg-reconfigure grub-pc' and 'grub-install /dev/vda' are run
And also:
run-parts: executing /etc/kernel/postinst.d/zz-update-grub 4.4.0-116-generic /boot/vmlinuz-4.4.0-116-generic
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-4.4.0-9025-euclid
Found initrd image: /boot/initrd.img-4.4.0-9025-euclid
Found linux image: /boot/vmlinuz-4.4.0-116-generic
Found initrd image: /boot/initrd.img-4.4.0-116-generic
/run/lvm/lvmetad.socket: connect failed: No such file or directory
From the install log you can see that we install grub2 at 2.02~beta2- 36ubuntu3. 17. 36ubuntu3. 17)
..
Unpacking grub2-common (2.02~beta2-
..
'dpkg-reconfigure grub-pc' and 'grub-install /dev/vda' are run
And also:
run-parts: executing /etc/kernel/ postinst. d/zz-update- grub 4.4.0-116-generic /boot/vmlinuz- 4.4.0-116- generic 4.4.0-9025- euclid img-4.4. 0-9025- euclid 4.4.0-116- generic img-4.4. 0-116-generic lvm/lvmetad. socket: connect failed: No such file or directory
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-
Found initrd image: /boot/initrd.
Found linux image: /boot/vmlinuz-
Found initrd image: /boot/initrd.
/run/
Then during boot we see
[ 0.000000] Command line: BOOT_IMAGE= /ROOT/zfsroot@ /boot/vmlinuz- 4.4.0-9025- euclid root=ZFS= rpool/ROOT/ zfsroot ro console=ttyS0
So we have successfully booted from root on a zfs system.