Need compression on the hard drive like for a freenas plex media server

the harddrive is at /dev/sdb with UUID=b70ca85a-d6ae-4d99-a073-b52af3d077a8

on the fstab I was told to do
UUID=b70ca85a-d6ae-4d99-a073-b52af3d077a8 /home/lance/plex/zfs btrfs defaults,compress=zlib:9,autodefrag 0 0

how do I do snapshots? or fsck -y if their is corruption on the drive.