[Samba] Odd, slow Windows XP client download behavior

[Ryan Novosielski]

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Kimon Gazis wrote:
> I have the very same situation here with Samba 3.0.28 (amd64 debian etch
> testing) and my two XP client machines (32 Bit and x64 Prof. Edition
> both SP2). FTP speeds are at reasonable levels in both directions and
> SMB uploads to the server as well whereas SMB downloads onto the client
> machines are extremely slow (around 300KB/s).
> 
> I can also confirm the strange effect described by Chris with rising
> downstream speeds when simultaneously uploading something. In my case I
> had a speedtest using "netio" pushing datagrams onto the samba server
> eg. completely smb unrelated! I checked the other direction having
> simultaneous downloads and yielded that effect as well.
> 
> The problem is independent of the client's network interface as I tried
> both the WLAN 54 adaptor and the Realtek GBit NIC on XP client side.
> With contrast to Chris I had no differences when playing with samba
> parameters like oplock (also no difference when done on the windows client).
> 
> I booted one client machine to debian etch (stable) and ran tests using
> NFS and FTP yielding full GBit LAN speeds.
> 
> I tested Windows Server 2003 clients inside VMWares running on the XP
> clients and on the samba server itself. No performance issues there.
> Downloading files from the windows VM running on the samba server (!)
> onto the XP clients works like a charm as well. (So does the other way
> round!). SMB communication between the two XP machines works anyway.
> 
> I finally smbmounted shares of the XP clients on the samba server and
> copied files onto them at reasonable speeds (around 40MB/s). Copying
> (downloading) onto the server was around 20MB/s.
> 
> I have no other samba problems. Everything else works fine: browsing,
> printing, WINS etc.
> 
> In my opinion there is no connection to a Hardwareproblem. Instead we
> experience some behaviour of the XP client machines that cause this. It
> seems to be SMB/CIFS related but I think we need to further investigate
> to get more hard data. Maybe capture some SMB packets using wireshark
> while doing the downloads and compare them ?!? However I am no
> networking guy so I would need some guidance on what to do exactly.
> 
> cheers
> Kimon

Someone had a problem here awhile back that was odd and traced it to a
TCP window problem. You might search the archives.

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 |Y#| |  | |\/| |  \ |\ |  | |Ryan Novosielski - Systems Programmer II
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