LinuxQuestions.org - [SOLVED] Way to total the columns in a df -h

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Way to total the columns in a df -h

Hi everybody. I need to get total space available, total space used, and total space available for all my servers.

What I was planning to do was log into each of them, do a df -h, then add up the size, used, and avail columns manually.

Is there a better/faster/easier way to do this?

On a single machine to get "all" freespace into one number:

Code:

df -lP | awk '{total+=$4} END {printf "%d", total/2^20 + 0.5}'

You can build a script around running that on each machine and adding the numbers together.

Very cool, thanks. How do I tweak that to use for the other columns? change the $4 part?

Correct. $4 is the column number.

Instead of using | to pipe the output of df to awk I would use this

Code:

< <(df -lP) awk '..awk stuff here ..'

Probably makes little difference here, but using that instead of | means you don't have awk in a subshell ( instead df is in the subshell, and its output is passed to awk )

A better example is a while read loop

Code:

unset Array Array2

while read a;do Array+=($a);done < <(df -l --output=avail);echo ${Array[@]}

df -l --output=avail|while read a;do Array2+=($a);done ;echo ${Array2[@]}

In the first, the bash array 'survives', where as the second it is lost

Anyway
You will almost certainly want to apply either in conjunction with a passwordless ssh login, using public keys

Example

Code:

for Server in Server1 Server2 Server3;do

    echo $Server free = $(ssh User@${server} "awk '/dev/{total+=$4} END {printf "%d", total/2^20 + 0.5}' < <(df -lP)")

done

pretty cool stuff there, thanks