Can any body provide me the shell script for checking a filesystem size and once it goes above a provided threshold the automatic backup starts...

This is a database forum. This however might give you a start. #!/bin/ksh MAILTO="user@host.com" echo "df -k output for `date` `uname -a`" > /tmp/df.out case `uname -s` in SunOS | Linux | OSF1 | UNIX_SV | FreeBSD ) if [ -s "/etc/redhat-release" ] ; then cat /etc/redhat-release >> /tmp/df.out ; fi set -- `df -k | sed -e 's/%//g' | awk '/^\/dev/ { printf("%s %s\n", $5, $6) }'` ;; HP-UX ) set -- `bdf | sed -e 's/%//g' | awk '/^\/dev/ { printf("%s %s\n", $5, $6) }'` AIX ) set -- `df -k | sed -e 's/%//g' | awk '/^\/dev/ { printf("%s %s\n", $4, $7) }'` ;; esac while [ $# -ge 2 ] ; do CAPACITY=$1 FS=$2 shift 2 if [ $CAPACITY -gt 90 ] ; then echo "$FS is at $CAPACITY %" >> /tmp/df.out fi done if [ `wc -l /tmp/df.out | awk '{ print $1 }'` -ge 2 ] ; then cat /tmp/df.out | mail -s "`date`" $MAILTO fi