> Why are the file descriptor limits still so low?  I understand that for most
> things it's fine, but when building a super high performance mail server,
> this just isn't enough.  Can this setting be changed on the fly yet like in
> Slowlaris?  

are you using 2.2 or 2.4? in 2.2, the default was 4096 file descriptors, in
2.4 the default is raised to 8192. (look in /proc/sys/fs/file-max).

to change this, either:
echo <value> > /proc/sys/fs/file-max
or:
sysctl -w fs.file-max=<value>

you can also put:
fs.file-max=<value>

in your /etc/sysctl.conf file, if your distro uses that. (RH does, SuSE
doesn't by default). then it should be read in at boot time. 
alternatively, put the 'echo <value> > /proc/sys/fs/file-max' in whatever
your distro uses for rc.local.

'man sysctl' for more info.

Carl Soderstrom
-- 
Network Engineer
Real-Time Enterprises
(952) 943-8700