Fixed: OpLocks caused the corruptions/slowness (Was: How Samba let us down)

[David W. Chapman Jr.]

On Fri, Nov 22, 2002 at 08:44:34AM -0800, Russell Senior wrote:
> >>>>> "jra" == jra  <jra at dp.samba.org> writes:
> 
> jra> Clients commonly ignore oplock breaks because of network problems
> jra> (borderline hubs etc.). Many people are suffering from network
> jra> hardware that performs adequately in light use situations and
> jra> fails under heavy load. I myself have ended up junking hubs with
> jra> this problem.
> 
> I *still* don't understand how flaky hardware could be the problem.
> TCP connections are supposed to be reliable.  If flaky hardware is
> eating packets, then surely the sender, failing to get a timely ACK
> will resend?  I can understand a flaky client getting the break and
> not responding with the appropriate action, but I don't understand how
> a hardware level problem can break TCP communication, except in the
> obvious and persistent way of not having a connection at all.  Please
> someone, wump me with a clue stick.

Duplex problems are a simple example like setting full-duplex on a 
half-duplex switch might.

A bad cable or NIC could cause intermitten problem as well.  Yes 
packets would get retransmitted, but who's to say the retransmitted 
packets won't get dropped as well?

-- 
David W. Chapman Jr.
dwcjr at inethouston.net	Raintree Network Services, Inc. <www.inethouston.net>
dwcjr at freebsd.org	FreeBSD Committer <www.FreeBSD.org>