Slow Copy WinXX - Linux/Samba :-(

[Bill Moran]

David Rankin wrote:
> 
> I never thought it would happen to me, but it did...
> 
> I have read threads about slow copies from WinXX to Linux/Samba on the
> list in the past, but I don't recall a concise answer regarding what the
> cause was.

I don't have the answer for you, but hopefully I can help you with
debugging it. I'd really like to know what causes this before it happens
to me ;)
First off, please verify that it isn't the client causing the problem.
IOW: try the copy from win95, win98, ME, NT or whatever client your
using and make sure it is a problem on all of them (and a consistent
problem as well) You may have already done this, but you didn't say so,
so I'm bringing it up.
Check the samba log files for the clients that are having the problem.
Sometimes there's a big red flag there. If there isn't, trying
increasing the log level and see if something shows up.
If that doesn't uncover anything, run a tcpdump or ethereal capture on
the Linux box while causing the problem to occur. If you're not familiar
with debugging packet streams, I would suggest that you learn a bit
about it, since it's an invaluable debugging tool. Feel free to send
output to me if you have questions. Also (as stated by Andrew) verify
that the hub/switch isn't seeing a large number of collisions. Also run
ping back and forth for a while and make sure the connections are
reliable. (There have been a number of times when I've tried debugging
the heck out of a server only to finally discover that the CAT5 cable
wasn't reliable! doh!)
Try removing pptpd - especially if it's the only thing that you changed.
You may have introduced routing problems that are producing a lot of
packet traffic that's going the wrong way.
If none of that helps, try running top and/or systat while causing the
problem. See if your disk usage is maxed or your processer usage has
topped out. This may help direct you toward the problem's cause. Look
for memory usage as well - is the box swapping a lot? You may have a
process somewhere that's gone awry and started leaking memory, starving
the samba processes.
Then go back and do all these tests again! I'm serious. Human
fallibility, as you state, has caused me to miss many obvious things
because the boss was leaning over my shoulder insisting to know when the
problem would be fixed.

Most important, let us (on the list) know what fixes it.

Hope this helps,
Bill