For networking with DBIsam, opportunistic locking must be disabled.
There had been some hints here in this forum how to set registry entries, and this worked well until Windows XP and Win2003Server.

However, there seem to be problems in networks with Win7 clients and Win2008Server. There had been updating and write access errors reported sometimes in busy environments. I digged a bit deeper into the problem and found numerous sites which describe exactly this problem with other ISAM databases and where it is written that the problem may be the SMB2.0 protocol, which is used by Win7 and WinServer2008.

Finally I found these pages:

http://www.dataaccess.com/whitepapers/opportunlockingreadcaching.html
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q296264   (also linked from somewhere on this site)

There it is told that the SMB2 protocol must be disabled, because for SMB2.0 you can't turn off the opportunistic locking. None of my users like this. One main advantage of my software is that it is easy to install and that you can work in a network without any additional actions like installing SQL servers etc. This would turn into its opposite if now the users will have to do those SMB modifications, which are different for the server and the clients. Registry values are no problem since they can be set by the application's setup.

I also found the values

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Lanmanworkstation\Parameters
 DirectoryCacheLifetime, FileInfoCacheLifetime, FileNotFoundCacheLifetime
which should be set to 0.
It is told that this would have the same effect to disable any caching and therefore the opportunistic locking also.

I am a bit worried. I can't afford to make it too complicated for my users...
Can anyone give me a good advice what has actually to be set in networks with Win7 and Server2008, so that we have the same reliability with peer-to-peer DBIsam access like with WinXP/Server2003?

I can't believe that this is not possible with the current Windows versions.

Thanks in advance
Stephan Krämer

Stephan

I can't help you, you seem to know a lot more about this issue than I do I only use file sharing mode for local single user access, for multi-user I always use Client/Server. It's not as hard to set up as you might think, you should perhaps consider moving to C/S.
Anyway, I just wanted to thank you for sharing all this information with us.

--
Fernando Dias
[Team Elevate]

But I wanted to get some help here...

Is there nobody of ElevateSoft who knows "more than I"? I don't believe that I know enough, otherwise I would not have asked...
C/S is no option for me for severe reasons. One of the most important ones is the easy installation.

Stephan Krämer

Stephan,

<<Is there nobody of ElevateSoft who knows "more than I"? I don't believe
that I know enough, otherwise I would not have asked...>>

I'm sorry for not being able to help, I just wanted to thank you for the
information, hoping someone else with more experience with file-sharing
could give you some help. Please note, I don't work for Elevate, I'm just a
user like you - the tag only means I volunteered to help in the newsgroups
when I can, and if I am able to. If no one comes up with the information you
need, I suggest you to send an email to Elevate support.

<<C/S is no option for me for severe reasons. One of the most important ones
is the easy installation.>>

It's not that hard, only one additional setup for the server and a few
settings.
From the top-of-my-head, the only extra settings apart from the server
installation would be to open 2 ports on the server firewall, but in return
you wouldn't have to deal with folder sharing and security.

--
Fernando Dias
[Team Elevate]

Stephan,

I would suggest you email Elevate support directly so they can comment
on this.

These are mostly peer-supported groups and i know many of us use C/S
more than file-sharing.

As you have done the work and assuming disabling SMB2 (or opportunistic
locking ) works and resolves the problems then that might be your only
way out (or to go C/S route which as Fernando says is straightforward
and likely easier than disabling SMB2 in terms of setup/instructions).

Raul


On 8/13/2012 4:32 AM, Stephan Kraemer wrote:
> But I wanted to get some help here...
>
> Is there nobody of ElevateSoft who knows "more than I"? I don't believe that I know enough, otherwise I would not have asked...
> C/S is no option for me for severe reasons. One of the most important ones is the easy installation.
>
> Stephan Krämer
>

Stephan,

My response via email:

=====================================================

<< For networking with DBIsam, opportunistic locking must be disabled. >>

That's not true, at least not with SMB1.  Perhaps you're thinking of the
BDE/Paradox ?

<< Can anyone give me a good advice what has actually to be set in networks
with Win7 and Server2008, so that we have the same reliability with
peer-to-peer DBIsam access like with WinXP/Server2003? >>

Unfortunately, we do not have any control over bugs in Windows OS's, whether
they are in the SMB layer or elsewhere in the network redirector  layer.  If
something is not working correctly in such an environment, then the only
*guaranteed* remedy is to use the DBISAM Database Server instead.  It's the
only way to bypass the bugs and ensure 100% accurate operation.  In general,
Microsoft doesn't seem overly-concerned with bugs in SMB2, so you're
probably going to be fighting an uphill battle trying to get any incarnation
of SMB2 to work properly in a heavy-usage, data-sharing environment.

As you indicate, you can remove these bugs by disabling SMB2, but if that's
not an option, then the only other option is the DBISAM Database Server.

I also found this, although I don't think that the results have been 100%
successful, and it's a mess to implement:

http://www.caseware.com/support/caseknowledge/kb-271

And there's this:

http://support.microsoft.com/kb/2028965

I get the impression that MS either a) doesn't know what is causing the
issue, b) doesn't care about the issue, or c) a little of both.

Tim Young
Elevate Software
www.elevatesoft.com