[Samba] Locking Problems

[Jeremy Allison]

On Mon, Jun 28, 2004 at 05:46:46PM +0100, David Nash wrote:
> 
> In addition to printing problems, we seem to have problems with locking.
> We have a few shares that hold MS Access databases for PC client
> applications.  We set these up using 'oplocks = no' and also tried
> 'strict locking = yes'.  However, when loading the database on one PC,
> we got application errors saying that other users were using the system.
> We set 'oplocks = yes' and were able to run the applications.  However,
> the users had application errors mid way through the day (corrupted
> database) and we had to restore from a safe copy.  We spoke with the
> application provider, and they've sent us a file called 'oplock.knn'
> that they advised us to run on all Windows XP clients to stop this sort
> of corruption.  The only thing is, they were unable to tell me what
> modifications it makes to the registry.
> 
>  
> 
> Basically, I'd like to know what Samba settings to use (in the [global]
> and share parts) to have secure and corruption-free multi-user access to
> files and databases.  Or is there no easy answer?

What version of Samba ? Firstly, ensure there are no oplocks on the
share holding the multi-user db. Seconly, ensure you have strict locking
enabled (on by default in 3.0.x). Thirdly, and most importantly, ensure
you have the *very* latest redirector hotfixes for the clients accessing
the db. I don't know of any locking bugs in the Samba code (we have some
quite extensive torture tests we pass) but I do know that the redirector
code in many Windows clients needs patches.

Jeremy.