hardware/optimizations for a download-webserver

[Henrik Heil <hhml@zweipol.net>]

Hello,
please excuse my general questions.

A customer asked me to setup a dedicated webserver that will offer ~30 
files (each ~5MB) for download and is expected to receive a lot of 
traffic. Most of the users will have cable modems and their download 
speed should not drop below 50KB/sec.

My questions are:
What would be an adequate hardware to handle i.e. 50(average)/150(peak) 
concurrent downloads?
What is the typical bottleneck in this setup?
What optimizations should i apply to a standard woody or sarge 
installation? (anything kernelwise?)

I have experiences with not so specialized servers (apache1.x/php4.x 
hosting on debian/woody/sarge) but never really hit any limits with these.

I thought about:

- tuning apache (oviously) -- raising Max/MinSpareServers, AllowOverride 
none, FollowSymLinks,...

- putting the files on a ramdisk or using mod_mmap_static (only ~600MB 
alltogether)

- replacing apache with fnord (http://www.fefe.de/fnord/) or cthulhu 
(http://cthulhu.fnord.at/). Can anyone share experiences with these?

- (as a last resort) using 2 loadbalancing servers with lvs 
(http://www.linuxvirtualserver.org/).

Thanks,
Henrik

--
Henrik Heil, zweipol Coy & Heil GbR
http://www.zweipol.net/