Eureka! Slow Samba transfers resolved!

[John H Terpstra]

On Sun, 19 Jan 2003, Jean-Marie White wrote:

> I just spent so much time troubleshooting why *some types* of samba
> transfers were slow that I thought I would  share how I resolved the
> problem.
>
> This problem had been going on for ever.  As far as I could tell, it was
> only happening with winamp (MP3 player).  All my MP3s reside on my Linux
> box and I was trying to access them from my PC running Windows 2000.
>  What was throwing me for a loop was that Windows Media player seemed to
> be more successful at playing them !  What would happen is that Winamp
> would freeze and nothing would happen.  I had then decided to just copy
> my MP3s back to my PC.
>
>
> Then, last night I started using FrontPage for some reason or another,
> and when I tried to publish my web site to my Linux box, then behavior I
> had observed with my MP3s started plaguing FrontPage as well.
>
> I went through all the troubleshooting guides, learned about every samba
> configuration options:  I was able to successfully transfer a 100M file
> in either direction (linux->pc or pc->linux) using the File Explorer
> without any problem.  But I just couldn't for the life of me understand
> why winamp and FrontPage were having problems.
>
> Then I decided to use ethereal and try and understand what was actually
> happening on the wire.  I realized that when winamp or FrontPage were
> trying to transfer files, Linux was ending up retransmitting the same
> frame over and over without ever receiving a TCP acknowledgment for it.
>  Then the PC would eventually tear down the session and re-establish the
> session and restart the transfer. An article that I read
> (http://www.dd.iij4u.or.jp/~okuyamak/Documents/tuning.english.html) was
> talking about how Windows could mysteriously drop packets, and I started
> thinking that maybe packets were being lost due to some hardware problem.
>
> So I looked at my PC network card configuration (Linksys LNE 100TX Fast
> Ethernet) and saw that the "Connection Type" was set to auto-detect.
> (My PC is connected to my Linux box through a Linksys 8-port Workgroup
> Switch - Ehterfast 10/100)  So I thought, maybe having to ends that
> "auto-detect" each others speed is not good.  So I changed my
> "Connection Type" to 100 TX Full Duplex and VOILA!  All my problems
> solved, winamp is happily playing away and FrontPage can publish my
> whole web site in seconds.

The problem and solution you describe here is very common. It also happens
to be the least expected, thus we have had many queries on this list
regarding samba problems that were in fact hardware issues like yours.

Thank you for sharing your experience. This is valuable feedback.


- John T.
-- 
John H Terpstra
Email: jht at samba.org