[Samba] smbfs: intermittent failures when accessing W2K server

[Dave Humphreys]

I think I am experiencing a problem with samba 2.2.8 and kernel 2.4.20.

I am using these versions on a number of computers in a render farm. These
(Linux) computers use smbfs to access a Windows 2000 file server. 

Two things that I notice:

1) The rendering application (Maya) fails due to a failure to access files on
the file server when first run after the Linux machine is started. Subsequently,
all is usually well. I have set the timeout on the Windows server to a very long
time, so that, once established, the connection is maintained. If I don't do this,
the application will fail the first time it is run after Windows has timed the
remote share out.

2) When a number of the Linux computers are running and simultaneously accessing 
the same file on the Windows server, I get intermittent file access problems, e.g.:

 Maya Fur Renderer: Error, couldn't open /projectserver/Project_Data/BobbyP/Work/FURTEST/furEqualMap/tmp_nurbsTorusShape1_eqMap.iff
 Maya Fur Renderer: Error, Reading of tmap /projectserver/Project_Data/BobbyP/Work/FURTEST/furEqualMap/tmp_nurbsTorusShape1_eqMap.iff failed

If I rerun the job, the files are likely to be read without a problem.

It seems to me that when the application tries to open a file, Linux reports
an error rather prematurely. In the situation (1), if the Windows server is
allowed to time out the remote mounts, then Linux has to re-mount the share
when the file access is attempted. I'd have thought that it should not report
an error to the application unless that process is attempted and fails. It seems
that an error is reported if there is the slightest hitch or delay.

My gut feeling is that the problem I see in (2) is due to a similar situation,
this time caused because of a number of simultaneous accesses to the file on the
file server resulting in a delayed response.

Can anybody point me in the direction of a solution, an explanation, or fruitful
further investigation?

Thanks,
Dave Humphreys