09 May 2007 Script to unmount Busy Devices

First the script tries to umount the drive normally. If that fails, it tries to restart famd which is the most common problem. If that fails it tries to restart xinetd. If that fails it uses the command fuser -ki which asks you if you want to kill each process that’s using that folder. Be careful with this – you should know what each process is before you kill it. If that fails, probably because you didn’t kill all the processes, it asks you if you want to lazily unmount the volume, which removes the drive even though processes are still using it.

#!/bin/bash

if [ `whoami` != "root" ]; then
      echo "You must run this as root"
      exit
fi

# testing args
if [ $# -ne 1 ]; then
  echo "usage : $0 "
  exit
fi

dir=$1

# first try unmounting it without doing anything special
testumount=`umount $dir 2>&1`
if [ `echo $testumount | grep "not mounted" | wc -l` -gt 0 ]; then
      echo "$1 isn't mounted, exiting"
      exit
fi
if [ `echo $testumount | grep "not found" | wc -l` -gt 0 ]; then
  echo "$1 does not exists, exiting"
  exit
fi

if [ `echo $testumount | grep busy | wc -l` -gt 0 ]; then
       echo "Having trouble, checking famd..."
else
     echo "unmounted $dir without any trouble..."
     exit
fi

# check famd
if [ `ps -e |grep famd|wc -l` -gt 0 ]; then
      /etc/init.d/famd restart
      # try unmounting again
      if [ `umount $dir 2>&1 | wc -l` -gt 0 ]; then
            echo "I tried restarting famd, but that didn't work. checking xinetd"
      else
            echo "Unmounted $dir by restarting famd"
            exit
      fi
else
      echo "famd isn't running so it couldn't be that.."
fi

# check xinetd
if [ `ps -e | grep xinetd | wc -l` -gt 0 ]; then
      /etc/init.d/xinetd stop
      # try unmounting again
      if [ `umount $dir 2>&1 | wc -l` -lt 1 ]; then
            /etc/init.d/xinetd start
            echo "Unmounted $1 by restarting xinetd"
            exit
      fi
      /etc/init.d/xinetd start
      echo "I tried stopping xinetd, but that didn't work."

else
      echo "xinetd isn't running so it couldn't be that.."
fi

echo
echo "I'm going to list processes that are using the folder you are
trying to umount. Answer whether you'd like to kill them or not.
You should look up each process before you answer. use the
following command in a separate shell:"
echo
echo "	ps -e | grep
"
echo
echo "where 
 is the number of the process."
echo
fuser -ki $dir
echo
if [ `echo $testumount | grep busy | wc -l` -gt 0 ]; then
      echo "OK, this is the last resort. Do you want to umount the volume using "
      echo "the -l option? According to the umount man page -l means:"
      echo
      echo "	Lazy unmount. Detach the filesystem from the filesystem
      hierarchy now, and cleanup all references to the filesystem as
      soon as	it is not busy anymore.  (Requires kernel 2.4.11 or later.)"
      echo
      echo "Use -l option? (y\n)"
      read yn
      if [ $yn == "y" ]; then
            umount -l $dir
      else
            echo "OK. Sorry I couldn't help"
      fi
else
      echo "You're all good :)"
fi

exit

Tags: bash, fuser, grep, mount, wc, xinetd

Posted by Hans-Henry Jakobsen