Answer by Jeff for ZFS Datasets dissappear on reboot

I also had the problem of the zfs disappearing after a reboot. Running CentOS 7.3 and ZFS 0.6.5.9 Reimporting brought it back (zpool import zfspool) only until the next reboot.

Here's the command that worked for me (to make it persist through reboots):

systemctl preset zfs-import-cache zfs-import-scan zfs-mount zfs-share zfs-zed zfs.target

(Found this at: https://github.com/zfsonlinux/zfs/wiki/RHEL-%26-CentOS )