27.6. nfsdown

If you have nfs on your system you might find this script handy. I look after several machines and periodically I may have to reboot one of them during normal working hours. This usually has to be done as quickly as possible.

As I have remote directories mounted all over the place, I do not want to have to rely on the rebooting process to take care of the nfs unmounting. I would rather do it myself; besides it’s faster than letting the machine do it.

I just run the script (which is on all the machines) and all the nfs mounts get unmounted, allowing me to do a faster reboot.

The script holds a list of machines that I have nfs mounts on. A for loop loops around this list, doing a grep of each host through the df command. The nfs directories that are mounted are in the form of:

machine:remote_directory 

This string is held in the variable NFS_MACHINE. This variable is then used in the umount command.

Here’s the script.

						$ pg nfsdown 
#!/bin/sh 
# nfsdown 
LIST="methalpha accounts warehouse dwaggs" 
for LOOP in $LIST 
do 
  NFS_MACHINE=`df -k | grep $LOOP | awk ‘{print $1}’` 
  if [ "$NFS_MACHINE" != "" ]; then 
    umount $LOOP 
  fi 
done