[Samba] Samba 3: bad read performance

[Dmitry V Shurupov]

Hi all!


We use Samba 3 server for some video stuff (editing, rendering, and so
on) -- that's why performance is critical. We've tried a lot smb.conf
options, but Samba can't satisfy our requirements.


Our server configuration is as following:
* Hard drive: RAID5 (8 x Seagate 7200.10), 3ware 9550SX-8LP controller
* NICs (trunked): 2 x Broadcom NetXtreme BCM5704
* Processor: Opteron 270
* RAM: 4 Gb
* File system: XFS
* Operating system: Gentoo Linux (kernel 2.6.24-r3)
* Samba version: 3.0.28, 3.0.28a

Our client configuration is as following:
* Processor: 2 x Opteron 270
* RAM: 4 Gb
* NICs (trunked): 2 x Broadcom NetXtreme BCM5704, 4 x NIC Intel
Corporation 82546GB.
* Operating system: Gentoo Linux (kernel 2.6.23-r9)

(We test Samba with our router to get better results.)

Our server & client are connected with Allied Telesis AT-9448T/SP.


And... Our testing results (MByte/s):

           Read   Write
 disk       190     135
 ftp        111     111
 samba       23      90

(With 5 connections we get the same: 5 x 23 MByte/s.)

We've tested our Samba server with:

1) time cat file > /dev/null (on mounted SMB directory)
2) bonnie & bonnie++ (on mounted SMB directory)
3) time cp file /tmp/file (on mounted SMB directory)
4) smbclient

We've tried SMBFS and CIFS, different oplock and socket options ("read"
performance varies from 17 to 25 MByte/s).


Samba HOWTO tells:
> The Samba server uses TCP to talk to the client, so if you are trying
to see if it performs well, you should really compare it to programs
that use the same protocol. The most readily available programs for file
transfer that use TCP are ftp or another TCP-based SMB server. 
(http://www.samba.org/samba/docs/man/Samba-HOWTO-Collection/speed.html#id2687128)

So, our Samba "read" results are really sad. What can we do to make
Samba perform better?


-- 
Dmitry Shurupov,
http://www.shurupov.ru/