[Samba] single stream performance issue, Win2K, WinXP, Samba 3.2.5-4lenny7 (Debian Lenny)

Stan Hoeppner stan at hardwarefreak.com
Mon Jan 25 16:30:34 MST 2010

Volker Lendecke put forth on 1/25/2010 1:28 AM:
> On Mon, Jan 25, 2010 at 12:14:36AM -0600, Stan Hoeppner wrote:
>> Volker Lendecke put forth on 1/24/2010 6:51 AM:
>>> On Sun, Jan 24, 2010 at 02:09:51PM +0200, Michael Wood wrote:
>>>> Except that he said "I can copy files between the Win2K and WinXP
>>>> machines at just over 10MB/s in a single stream and max out the 11MB/s
>>>> with two streams."  I am assuming he used the same client in that test
>>>> as he did with the test against Samba.  So from what he's said it
>>>> seems that he gets more speed with a Windows server than with Samba
>>>> for the same client.
>>> So what we need is a full network trace of both cases.
>> Actually I'll give you something slightly different, and more to the original
>> question.  I've taken two tcp captures on the Samba server machine.  Both
>> transfers were performed using the Windows 2000 cli "copy" command pulling a
>> 36MB avi file from a share on the Samba server.  The first test was a single
>> stream copy.  The second test was a dual stream copy of the same file
>> concurrently to two different destination directories.  I also had iftop running
>> during the tests.  The single stream transfer maxed out at just over 64Mb/s.
>> The dual stream test maxed out at 92Mb/s.  Following are the two tcpdump output
>> files using "tcpdump -p -s 0 -w FILE port 445":
>> http://www.hardwarefreak.com/smb_single_stream
>> http://www.hardwarefreak.com/smb_dual_stream
> The dual-stream one is kindof limited help. The interesting
> piece is how Win->Win does its thing faster, so we need to
> see that one.

I've been busting my but trying to get you something meaningful.  This dump is
less than optimal for two reasons, but it's the best I can get you thus far.

1.  Running tshark on Win2K creates a huge network performance hit and thus b/w
numbers for small file (<250MB) transfers don't come close to accurately
describing the real world.  With tshark running the b/w is less than half of
normal with small files.

2.  Because of this I had to do a huge file copy to allow time for the client to
level off at peak performance, which is still ~500KB/s lower than normal due to
tshark overhead.

Anyway, the file is over 400MB.  It'll take quite a while to grab off my server.


Hope you are able to glean something meaningful from it.


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