Running ircu2.10.11 on FreeBSD

When running on FreeBSD, ircu can make use of the kqueue() event engine, which
results in much improved performance over the old poll()-based method. kqueue
is included in the more recent 4.x releases of FreeBSD.

In order for ircu to be able to serve many clients simultaneously, you need
to increase the maximum allowable number of open files in the system. To do
this, add commands such as the following during your system's boot sequence:

sysctl -w kern.maxfiles=16384
sysctl -w kern.maxfilesperproc=16384

Unless you will be serving thousands of clients simultaneously, you will not
need to do the following, unless of course you just can't stand having a
system that is not optimized to its limits :)

Build a custom kernel: Make your kernel as lean as possible by removing all
drivers and options you will not need. The following parameters will affect
performance, they are listed with suggested values only. For more information
on what they do exactly, see FreeBSD's documentation.

maxusers        2048
options         NMBCLUSTERS=65535
options         ICMP_BANDLIM

Also, you may wish to run the following at system startup (from /etc/rc.local,
or whichever other method you prefer):

sysctl -w net.inet.tcp.rfc1323=1
sysctl -w net.inet.tcp.delayed_ack=0
sysctl -w net.inet.tcp.restrict_rst=1
sysctl -w kern.ipc.maxsockbuf=2097152
sysctl -w kern.ipc.somaxconn=2048

Created by Sengaia <sengaia@undernet.org>, July 20 2002.