How to tell if nfs mount will fail

[Theresa Patrie]

Hi,
Is there any way to tell if an nfs mount will fail before you actually try to do it?? I have a script that runs in cron every 15 minutes and writes to a nfs-mounted directory. When nfs is broken, the script hangs. What can I put in the script to check if the needed nfs mount will work before trying to write to it?? Any ideas would be greatly appreciated!
Thanks,
Theresa

[Marco Santerre]

Other than trying to ping the host where the local mount point is, I don't have any other ideas of what tests you could do prior to actually going into it.

[Pete Randall]

Theresa,

I'm not sure that this would work and I don't have a broken NFS mount to try it on, but maybe you could try doing an "ls -l" on the directory and check it with "wc -l". If you don't get any lines back, then you're mount is probably broken.


Pete

[RAC_1]

Before you mount NFS directory, you can check if it accessable to you.

(Just ping will do)

Also you can use showmount to see if filesystem you want to mount is exported from server or not.

Further you can check ping response to see the network quality.

[Mark Grant]

You can't really but you could make your script time out by getting it to run a "sleep 30 && kill $$" in the background and killing $# if your file read is successful.

This basically translates to...

start a process in the background that will kill my script after 30 seconds. However, if my script works then kill the process that was about to kill me.

Crude but cute.

[Theresa Patrie]

I don't think ping is the way to go because mounts can fail for other reasons even if ping shows the machine is alive. "ls -l" will not work because that acutally also causes a hang if nfs is broken. I like the creative approach, Mark. I'll have to come up with a little script and check it out. From the responses so far, looks like a creative workaround is the only way to go...
Thanks!