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

Russell Senior seniorr at
Sat Nov 23 00:50:01 GMT 2002

>>>>> "David" == David W Chapman <dwcjr at> 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.

Russell> I *still* don't understand how flaky hardware could be the
Russell> problem.  TCP connections are supposed to be reliable.  If
Russell> flaky hardware is eating packets, then surely the sender,
Russell> failing to get a timely ACK will resend?  I can understand a
Russell> flaky client getting the break and not responding with the
Russell> appropriate action, but I don't understand how a hardware
Russell> level problem can break TCP communication, except in the
Russell> obvious and persistent way of not having a connection at all.
Russell> Please someone, wump me with a clue stick.

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

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

Uh, RFC793, section 2.6 maybe?  I think people would notice a total
network failure, so I am excluding that possibility.

Russell Senior         ``I've seen every kind of critter God ever made,
seniorr at      and I ain't never seen a meaner, lower, more
                         stinkin' yellow hypocrite than you!'' 
                                        -- Burl Ives as Rufus Hennessy

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