Script to check if File Systems are in read only mode

Today I'll share a quick script with which you can check if the file systems on your server have gone into read only mode. One way would be to touch a file and check but doing that on every file system on every server would involve a lot of time and overhead.
From some experimentation I've learned that if the file systems go into read only mode while a process is writing to it then the read only mode gets reflected in /proc/mounts command.

Here is a quick script to check the status and send out an email in case of issues:

#!/bin/bash

##########################################

#date: 01/02/2017                        #

#purpse: check Linux file systems are RW #

##########################################

cat /proc/mounts | grep ext4| awk '{print $2, $4}' | awk -F "," '{print $1}' | while read FS_NAME PERM

do

if [ ${PERM} != "rw" ] ; then

        echo -e "FS $FS_NAME is mounted with $PERM permissions. Please check \n" | mail -s "Read only FS on `hostname`" unixadmins@example.com

fi

done

You can integrate this script with a monitoring tool like HP OV or nagios.