[Pkg-samba-maint] Samba performance issue

[Fabien]

Hello,

sorry to write directly to you, but after long hours spent trying to 
solve this strange problem, I thought it could be handled better by 
speaking directly with you. I hope I'm not wrong...

While testing samba speed on my file server, using a fully tested 
gigabyte ethernet connexion, I encontered some very strange performance 
problems.

I had big speed differences when using samba locally, or via the network 
(gigabyte).

"Mb" stands for Mbytes.
	
* My server config :
  - AMD X2 4200+
  - 2 Go RAM
  - 4 x 500 Go --> RAID5
  - Gigabyte connection
  - Debian ETCH
  - debian package : Samba 3.0.24 (I also tried to backport the testing 
version => 3.2.5 but the results were exactly the same)


* My samba share folder is a partition of my RAID 5 (reading : 170 Mb/s 
& writing : 90 Mb/s).

* Here are my benchmarks (nearly the same from Linux or Windows) :

- Reading via ftp on the server (no samba) from a Gigabyte client :
  => 120Mb/s
- Reading on the samba server from a Gigabyte client
  => 35Mb/s

- Writting via ftp on the server (no samba) from a Gigabyte client :
  => 90Mb/s
- Writing on the samba server from a Gigabyte client :
  => 40Mb/s

I also noticed that if I try to read/write on the samba server from more 
than just one client, the results is exactly the same : the server 
bandwith limit is 35(up)/40(down) Mb/s.

/!\ When I mount the samba partition localy (on the server) I can read 
at 115 Mb/s or write at 90 Mb/s, which is the good behavior.

I tried MS Windows and Linux (etch) smbfs clients.

I did a lot of testing, using a 1Go RAM disk on both sides to avoid 
disks problems, and got the same test results.

Do you think that the problem could come from the Debian package ?

I investigated google a lot and found very few people reporting this 
strange behavior (mainly from ubuntu forums). I am pretty sure that 
several (every ?) people, at least from debian, are concerned. I think 
that they just didn't notice the speed problem (35Mo/s is still quite 
nice to be noticeable).

I found some people trying to tweak the samba buffers : they only got a 
little better speed (+ 5Mo/s).

My smb.conf file is attached.


Thanks for your help.

Cheers,

Fabien
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