[Samba] Samba and DOS databases (oplock settings not getting same results as under NT4)

[Robert Mortimer]

Before you reply note I have read the op-locks bit of the samba manual

We have a micro-focus Cobol (dos) database that ran on an old Novell server.
When we moved to NT4 performance bombed. We added the correct registry keys
to turn off op-locks on the NT4 server and all was OK for the next 6 years.
We have no moved to SAMBA but we can not get it to perform as well as our
old NT machine despite a huge hardware boost.

With Oplocks on performance is OK but we get more record locks than we used
to and often as the user moves to a new task there is a long delay
(presumably as other peoples op-locks are broken and the data is cached
locally)

With Oplocks off the performance is unacceptable. Reports that were taking
10 min on the old NT4 machine are now taking over an hour to run.

Using the sysinternal tools I see that the dos application is attempting to
lock individual portions of the data files. Is this possible on Samba
running on an ext3 file system. Is this a problem with samba of should I
look at my underlying file system. Any pointers welcome.

I am going to do some benchmarking over the next week all suggestions
welcome

We are running FC4 with samba-3.0.14a on the default ext3 filesystem.

Regards Robert