Checking disk space is easy. Open the terminal and enter df. This will tell you the size of each partition, how much used and how much free space.
Thanks for that, Neal. I figured there was an easy way, just didn't know it myself. ;-)
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 25G 22G 1.7G 93% /
tmpfs 1.4G 0 1.4G 0% /dev/shm
/dev/sda2 435G 21G 392G 5% /media/bbf
I figure the 93% used is likely the reason I was having issues.
D.