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

Linda Walsh samba at tlinx.org
Sat Jan 23 01:48:20 MST 2010

Igor wrote:
>  I don't find it strange at all. Your computer is acting as a traffic
>  proxy between two samba servers. If you have 100Mb network interface
>  your bandwidth should split exactly in two.
	But he said he doesn't get a split in two when a win2k server
is used (he gets 11Mbps).    I.e. Two network streams in two different
directions should NOT halve throughput, _unless_ something is operating
in half-duplex mode.   "100Mbps, full duplex" should, _easily_,
allow two 8 MBps streams if they are going in opposite directions.  

Stan wrote:
> Interestingly, if I launch a file copy with the SH> source file being
> on one smb share on the server, and the destination being SH> another
> smb share (separate filesystem) on the server, the combined throughput
> SH> is also 8MB/s, 4 up and 4 down, which is very strange as this
> should be two SH> distinct streams.
	I agree.  Is it possible your network device isn't running 
in FULL duplex?   

	Other things to check (to optimize speed compared to ftp):

	1) Ensure your communications are using TCP (port 445) and not
UDP (port 139).

	2) Ensure encryption (Sealing) is off.  

	3) Ensure packet Signing is off. 

The overhead of 2 & 3 contribute to around a 15% performance hit according
to 1 MS source.  (Obviously turning such things off presumes you are on
a 'safe' network consistent with FTP usage, vs. SCP/SSH).

	You need to make sure that, at least, one side has each of 
Sign and Seal turned off and the other side has it set to 'no' or 'auto'.
If one side has 'require' set for the feature, and the other has the 
same feature turned off, it will prohibit communications.

(who's been bummed by the huge drop in networking and disk performance
in windows 7).

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