[SOLVED] Run shell script on multiple linux servers

vanish78 · 05-15-2012, 07:13 AM

Hi There,
RHEL

I want a script that will check disk space on multiple servers. I can do a df -h with :

PHP Code:



for i in server1 server2 server3 
do 
ssh $i df -h 
done

But I want to run this script (which this forum helped me with!)

PHP Code:



#!/bin/sh 
for i in msrac01 
do 
ssh $i df=`df -Pl | grep "^/dev" | awk '{print $5, $6}' | sed "s/%//"` 
echo "$df" | while read percent fs 
do 
    if [ $percent -gt 90 ] ; then 
       echo "$percent" 
    fi 
done

Please help.

pan64 · 05-15-2012, 07:32 AM

I remember I saw this script, and I also remember I gave you a one liner instead of this terrible code.
So I suggest you to use a much simple script and you will be able to use that with ssh:

http://www.linuxquestions.org/questi...9/#post4659230

Code:

cmd="this is a one line long script"
for i in server1 server2 server3 
do
ssh $i $cmd
done

and also you may need take care of ' and " and ` signs.

colucix · 05-15-2012, 08:09 AM

I agree with pan64. Using a simple command is far simpler. In addition, to avoid the quotes headache you might run the df command remotely and parse it locally, e.g.

Code:

#!/bin/sh
for i in something
do
  df=`ssh $i "df -Pl"`
  echo "$df" | awk '/^\/dev/{sub(/%/,"",$5); if ($5 > 90) print $5, $6}'
done

adding something to identify the server from which you get some result.

Moreover, notice that usually you don't need to run grep, awk and sed together, since awk can do it all!

vanish78 · 05-16-2012, 10:39 AM

Hi,

Ok I used the "lighter script" :

PHP Code:



#!/bin/sh 
for i in server1 
do 
  df=`ssh $i "df -Pl"` 
  echo "$df" | awk '/^\/dev/{sub(/%/,"",$5); if ($5 > 95) print $5}' 
done

But not getting any results, but it works on server2. What can be the reason?

colucix · 05-16-2012, 10:48 AM

No filesystem with usage > 95%? What is the difference between the two servers in terms of OS, shell, awk version and so on?

pan64 · 05-16-2012, 11:42 AM

I would simplify it:

Code:

for i in <server list>
do
  echo server: $i  # if you want to print it just do it
  ssh $i df -Pl | awk ' here is the script '
done

you can also try awk -v server="$i" ' script ' if you want to handle the server name inside the awk script.