[Samba] Samba - XP performance problem

[Jonathan Johnson]

I can't say that this will apply in your situation, but I've seen where 
having stale "connections" to non-existent servers can cause a 
performance issue when browsing. Here's a couple of things to try:

1) Remove any shortcuts to non-existent network locations -- this 
applies to broken mapped drives, shortcuts on the desktop and in My 
Documents, and shortcuts in My Network Places

2) Look in the registry at 
HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2 (or 
...\MountPoints) -- Under this key, there will be several subkeys. Some 
of these are in the form of ##Server##Share -- if there are any of these 
that refer to nonexistent servers or shares, remove them. DO NOT remove 
any of the other keys, else your system might not boot properly. This 
key is seems to be the Windows version of the /etc/fstab file.

Nevertheless, I'm glad to see that you found something interesting. 
Hopefully, your research will help the developers solve some other 
nagging problems!

--Jonathan Johnson

David Beck wrote:

> Hello There,
>
> After having googled the whole internet for days I decided to go 
> public with this issue.
> The result of my google queries so far is that there are plenty of 
> others with the very same problem I have and noone posted a reasonable 
> answer to this:
>
> Using Samba 3 with XP gets bad performance. I tested this on Tru64 
> 5.1b and FreeBSD 5.3 with the very same symptoms.
> The throughput bw XP and Samba goes up and down. It starts transfering 
> with a reasonable speed and after having transfered around 16 megs it 
> slows down.
> I tried many configuration options regarding locking, tcp settings, 
> xmit size and every combination that could make any sense for me.
>
> Then I gave up with this configuration mess as I could lower the 
> performnce easily, but the performance jittering was the same.
>
> Now a few notes before I continue: I tested the FreeBSD server on the 
> loopback interface and the file write speed was around 43 Megs that is 
> close to the disks maximum. I also tested the XP machine with a 
> Windows  server and the write performnce was around 10 Megs on a 
> 100Mbit link. In addition to that the FreeBSD machine is at my home 
> and the Tru64 and the Windows server are where I work. I'm pretty sure 
> that this is not a network issue.
>
> After spending a lot of time with investigation I decided to go deeper 
> in this issue. I installed ethereal to capture the traffic and compare 
> the results bw XP-Windows and XP-Tru64. The test was to copy 50Meg 
> file to both servers and capture the packets. To my surprise the 
> conversation was quite different.
>
> XP-Windows (excerpt):
> - nt create and x
> - trans2: query file info internal
> - set file info
> - tcp data stream...
>
> XP-Samba (excerpt):
> - nt create and x
> - trans2: query file info internal
> - (query file info + write and x request) many times, incresing 
> offset, one byte length
> - tcp data stream....
>
> In case of XP-Samba, the last two steps are repeated many times.
> Large part of the effective bandwith is filled with query file info 
> and 1 byte writes.
>
> The packet data can be downloaded from these links:
>
> http://dbeck.beckground.hu/download/xp-samba.bz2
> http://dbeck.beckground.hu/download/xp-win.bz2
>
> I also made a screenshot of a bandwith monitor to show what I mean by 
> performance jittering:
>
> http://dbeck.beckground.hu/download/samba-performance-write.PNG
> http://dbeck.beckground.hu/download/samba-performance-read.PNG
>
> Please note that the original packet log for the 50 Meg file was very 
> large, so I kept only the interesting parts.
>
> Last, could anyone there, Samba and SMB wizards help me, how to solve 
> this performance issue?
>
> Thank you in advance,
>
> David.
>