I have a batch job that is running on a VAX. We just began experiencing a problem with a Stale NFS file handle. The script that is running doesn't abort and when the status of the script is checked it doesn't return any kind of error. Is there a way to abort this script when this error occurs?
Thanks!
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The problem is that it DOESN'T hang. I'm able to connect to the server, but when I do the cd to get to the directory, that part "fails" and it stays in the root directory. Since no real script error occurs, the files are ftp'd to the root thinking that the change directory worked.
Is that more clear?
I think I understand now. The script is running one one machine and it is tranfering data via FTP to another system. And it's the remote FTP server that experiences the Stale NFS file handle.
It would seem to me that the solution would be to have the script check the current working directory after the 'cd'. If the remote FTP server can't execute the 'cd' command a 'pwd' should reflect that. And, obviously, if you aren't in the correct directory, as shown by the 'pwd' command you can abort the transfer.
An ftp transfer package designed for scripted application like ncftp (http://www.ncftp.com/) might make it a bit easier to manage the transfer from within a script. I'm pretty sure that an 'ncftpput local-file ftp://remote-spec' will gracefully fail if the specified remote directory can't be written to.
Stale NFS file handle
is one of NFS' nasty things, means there is no way around this, usually. You (your script) needs to wait 'til the server send OK.
Most UNIXs tend to hang the affected process 'cause NFS is in the kerenl. I don't have any experiance with VAX, but assume that it is like other UNIXs.
Hi there,
If you are getting stale NFS file handles one thing to look for is old .nfs* files. There may be a lot of them on your system using quite a lot of disk space.
Regarding your script, there are a number of ways to check for errors. One way is to check the exit status of the 'cd' command.
Example:
cd /mnt/somefilesystem/direct
if [ $? -eq 0 ]; then
echo "Change directory was successful"
pwd
else
echo "Unable to change directory ... exiting"
pwd
exit 1
fi
Another way is to check the present working directory after running the 'cd' command.
Example:
cd /mnt/somefilesystem/direct
if [ "$PWD" = "/mnt/somefilesystem/direc
echo "Change directory was successful"
pwd
else
echo "Unable to change directory ... exiting"
pwd
exit 1
fi
Question: Is the filesystem automounted or is it permanently mounted? If you are accessing files regularly then I would recommend that you permanently mount it.
Regards, Nisus
http://www.omnimodo.com
Hi ahoffmann,
I did think of that but jjcolo mentioned above that the 'cd' command does execute and continues even though it is not in the correct directory.
As I do not have a VAX handy I cannot replicate the environment accurately.
jjcolo, we would be interested in knowing if my script is suitable to your needs. Please update the question when you get a chance to try it out.
Regards, Nisus
http://www.omnimodo.com
A stale NFS file handle should not hang any system, regardless of whether it's Unix or VAX. This error is returned when the filehandle is known not to exist, so it is a permenant error (ie. no amount of retrying will help).
I usually use 'set -e' at the start of a script to terminate on the first error. This traps the error with cd without any special error handling code.
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by: jleviePosted on 2002-11-07 at 11:06:39ID: 7421425
I'm guessing that the script simply hangs when it tries to access data residing on a stale NFS mount point. If that's the case you'd have to use some sort of timeout loop within the script or call some external program that can check the status of the resource and return an error (after timing out) if the resource isn't available.