By default mergerfs appears to try and mount before ZFS is mounted which causes the mergerfs filesytem to fail. To fix this we just need to add x-systemd.requires=zfs-mount.service to the /etc/fstab entry For example my /etc/fstab entry is below: /hdd*/mergerfs /data fuse.mergerfs splice_read,threads=4,allow_other,cache.readdir=true,cache.files=off,fsname=mergerfs,use_ino,dropcacheonclose=true,link_cow=true,category.create=mfs,cache.entry=120,cache.attr=120,x-systemd.requires=zfs-mount.service 0 0