It is a very crucial task to monitor disk space usage on any system. If not properly monitored it can end up with poor performance or application crash.
In this tutorial, I will show you a simple shell script that checks the used space on all mounted devices and warns if the used space is more than a threshold.
Shell Script Monitor Disk Space
Below shell script output the percentage disk space used.
#!/bin/bash threshold="20" i=2 result=`df -kh |grep -v "Filesystem" | awk '{ print $5 }' | sed 's/%//g'` for percent in $result; do if ((percent > threshold)) then partition=`df -kh | head -$i | tail -1| awk '{print $1}'` echo "$partition at $(hostname -f) is ${percent}% full" fi let i=$i+1 done
Script Result
bobbin@linoxide:/$ df -kh Filesystem Size Used Avail Use% Mounted on /dev/sda1 52G 4.7G 45G 10% / tmpfs 1.9G 0 1.9G 0% /lib/init/rw udev 1.9G 192K 1.9G 1% /dev tmpfs 1.9G 2.6M 1.9G 1% /dev/shm /dev/sda6 92G 22G 66G 25% /home
bobbin@linoxide:/$ ./df_script.sh /dev/sda6 at linoxide.lviv.example.com is 25% full
How this shell script works
#This set threshold value
threshold=”20″
#Counter, will be used later, set to 2, since first line in df output is description.
i=2
#Getting list of percentage of all disks, df -kh show all disk usage, grep -v – without description line, awk ‘{ print $5 }’ – we need only 5th value from line and sed ‘s/%//g’ – to remove % from result.
result=`df -kh |grep -v “Filesystem” | awk ‘{ print $5 }’ | sed ‘s/%//g’`
#for every value in result we start loop.
for percent in $result; do
#compare, if current value bigger than threshold, if yes next lines.
if ((percent > threshold))
then
#taking name of partition, here we use counter. Df list of all partitions, head – take only $i lines from top, tail -1 take only last line, awk ‘{print $1}’ – take only first value in line.
partition=`df -kh | head -$i | tail -1| awk ‘{print $1}’`
#print to console – what partition and how much used in %.
echo “$partition at $(hostname -f) is ${percent}% full”
#end of if loop
fi
#counter increased by 1.
let i=$i+1
#end of for loop.
done
Hi,
I got that error during runtime,Please refer below and take care!
line 11: ((: /: syntax error: operand expected (error token is "/")
Thanks,
Sutanu
I am not familiar with scripting.Please help me if i want output for multiple remote server.
Where i need to change the script.