====== Get Disk Space ======
One liner to get total, used and available disk space
<code bash>
df -Pk|awk '{ sum2 += $2 ; sum3 += $3 ; sum4 += $4} END { print sum2/1024/1024 " G, " sum3/1024/1024 " G, " sum4/1024/1024 " G"}'
</code>