[Samba] Oplock break request failures

[Simo Sorce]

On Tue, 2002-12-24 at 11:37, Ray Simard wrote:
> I hope someone can enlighten me on this.
> 
> Situation: NT network, Samba PDC, about 20 NT 4.0 workstations. log(s).smbd 
> are created per machine for easier analysis (as log.smbd.<NetBios Name>).
> 
> Not often, but often enough to be of concern, are errors in 
> request_oplock_break that seem to indicate that another smbd process that 
> should be listening for break requests on a UDP socket isn't, or isn't 
> responding. Some time ago, for some very strange reason, the system was 
> configured with share modes off, which caused these errors to occur 
> constantly. That was corrected and now they are infrequent, but not 
> infrequent enough, I suspect, to ignore.
> 
> One possibly significant fact: there are two subnets. The cross-subnet 
> browsing recommendations have been followed and we have no trouble browsing 
> across the subnets; but all of the failures I'm writing about occur on the 
> subnet which is remote from the one on which the Samba PDC resides. None of 
> the samba logs associated with any of the several NT workstations on the 
> local subnet with the Samba machine show this error. I can't see how that 
> would matter, given that the inter-process oplock break requests are simply 
> UDP communications and don't use subnet broadcasts - unless I'm mistaken, a 
> very real possibility. :-)
> 
> Does anyone have a hint on what might cause this, how to troubleshoot it more 
> fully, or if it's really nothing to worry about?

Oplock breaks are notified to client machines, and then clients must
answer in a given time (oplocks regards client caching).

If clients fail to answer in time, the server must consider them
broken/dead/whatever and break the oplock itself.
This of course means that it could have unconsistent data on disk, but
nothing can be done.

You have slow links, you may want to rise oplock breack times, but then
you may experience slower startup fo rapplications or slow file opening.

You may try with: oplock break wait time
But be sure you understand what this means, read carefullt the man pages
and use at your own risk :-)

Simo.

-- 
Simo Sorce    -  idra at samba.org
Samba Team    -  http://www.samba.org
Italian Site  -  http://samba.xsec.it