df -h Step 2: Next filter out file system and find out the percentage of space
(df / | grep / | awk '{ print $5}' | sed 's/%//g') Step 3: Write a shell script
If you don't want to step up to a full monitoring solution such as Nagios you can create your own scripts for monitoring the things that you want to monitor, such as disk space. The following script alerts you when your root partition is almost full.
#!/bin/bash
CURRENT=$(df / | grep / | awk '{ print $5}' | sed 's/%//g')
THRESHOLD=90
if [ "$CURRENT" -gt "$THRESHOLD" ] ; then
mail -s 'Disk Space Alert' it.subhashpatel@gmail.com << EOF
Your root partition remaining free space is critically low. Used: $CURRENT%
EOF
fiTo run it daily, for example, save the script to the file disk-alert.sh in /opt directory, change the email to your email, and add the following line at the end of /etc/crontab file.
@daily /opt/disk-alert.sh
