Samba scalability?

[Shawn Wright]

I'm in the process of upgrading several of our NT4 servers, and 
must decide what services I can safely migrate to Linux/Samba, 
and which need to remain on NT.

Currently our two NT4 server carrying the heaviest file sharing load 
deal with about 150 concurrent user connections, and will see 600-
1200 file locks during normal use. Most of this is user home 
shares, with some shared network apps thrown in; clients are 90% 
NT4 WKS, with some student win9x PCs and laptops.

I've run various low use samba servers over the past 5 years or so, 
but have never attempted to fully replace an NT4 box as they have 
been rock solid (surprisingly) for us. What samba issues should I 
be prepared to address to deal with this kind of load? Does samba 
benefit from an SMP system? How are the software RAID drivers 
in Linux? (the current NT4 box I'm planning to migrate to Samba 
over Linux is a PPro200 with 224Mb, and 3 Adaptec 3940UW 
SCSI cards, with 4 9Gb Cheetah drives running software RAID -
stock NT4 drivers)

I've heard talk about open file limits in the smbd process - is this 
only an issue with WTS clients? I'd appreciate any tips for tuning 
samba for this type of environment.

One more big question: I'm not tied to Linux by any means, as I've 
used various BSDs over the years, so I'd by interested to know if 
there is a particular advantage to running samba over a certain 
platform, OpenBSD, FreeBSD, etc?

Thanks for any help you can provide.

========================
Shawn Wright
Computer Systems Manager
Shawnigan Lake School
http://www.sls.bc.ca
swright at sls.bc.ca