FreeBSD SAMBA file server performance - strange behaviour

[Bill Moran]

In response to Nenad Mihajlovic <nenad at venturis.hu>:

> Hi all,
> 
> Recently I have received the reuest from the colleague to create the  
> homebrewn NAS for his small office, so I started checking the possible  
> options, and having good, long and stable relationship with FreeBSD  
> I've settled again for it.
> Machine is not something special, Pentium D with 1G RAM and single  
> SATA150 disk, 3Com 1G server card in the PCI slot, connected to the  
> desktop though 1Gbps unmanaged switch.
> If needed I'll provide the full config and setup information.
> 
> After installing the bare FreeBSD 7.0RC3 and Samba 3.x.xx - whichewer  
> was included in the packages - I wanted to have the job done quickly,  
> the machine appeared on the network and everyone seemed to be happy  
> and live happily everafter.
> Until dear friend of mine started using the machine to do the actual  
> work - basic editing of the wedding videos.
> 
> When trying to upload the single file to file server, he was getting  
> the varying speed of 5-13 MBps, from his machine to file server -  
> which is unacceptably low for any kind of transfer speed.
> 
> Interestingly enough, when he tried to copy _TWO_ files to file  
> server, the transfer speed vould jump to the 25-27 MB/sec and keep  
> permanent, without much fluctuation.
> 
> After I tried to copy the files from one directory to another, iostat  
> has shown me the speed in excess of 29 MB/sec while copying the files  
> between two directories on the same server, so the disk access should  
> not be the problem.
> 
> On the other hand, i experienced that when i try PING on the File  
> server's IP address from the fileserver, i get performance increase in  
> the transfer speed - the bigger the traffic i generate, the better the  
> results, which max out at 25-27 MB/sec with flood ping.
> 
> Has anyone else experienced any similar behaviour?

This is a pretty wild guess, but can you verify that the ethernet settings
are correct?  If the interface is set to autoneg, can you verify that
both ends (the FreeBSD machine and the switch itself) have negotiated
the same speed/duplex?

Wouldn't be the first time I saw a switch negotiate a different speed/
duplex than the NIC on the other end.

-- 
Bill Moran
http://www.potentialtech.com