Thanks for the help I'm just a little confused..
I followed the article
Disk /dev/sda is my disk
and the article said to
root=/dev/sda2 rootfstype=ext4 rootwait
in cmd.txt - is this correct to type it "sda2" even though my disk is "sda"?
Then when I reboot and "df -h" it says I have 28 gig freespace which the article says I need to free up space....
Do I need to check which disk I've booted off or something?