Disk Commands

To see a listing of disks partition table

fdisk -l
fdisk -l /dev/sda

To see the amount of disk space available on the file system

df -h
df -k /home

And to just get the % of space available in the /home directory

df k /home |tail -1| awk '{print $5}' | sed 's/%//'

Disk usage du shows the amount of data a directory uses

du -h
du -s

To print a list of directories in var with the amount of space each dir is taking up and sorted in decending order

du -s /var/* |sort -n