adduser nagios
mkdir /usr/local/nagios
chown -R nagios:nagios /usr/local/nagios
cd /usr/ports/graphics/gd
make install
cd your nagios source
important:define your gd location to generate statusmap,trends,and histogram cgi files
./configure --with-gd-lib=/usr/locol/lib --with-gd-inc=/usr/local/include --with-init-dir=/etc/rc.d
make all
pw groupadd -n nagcmd
pw usermod www -G nagcmd
pw usermod nagios -G nagcmd

=================================================================
make install-init
/usr/bin/install -c -m 755 -d -o root -g root /etc/rc.d
install: root: Invalid argument
*** Error code 67

Stop in /home/src/nagios-2.0b5.
=================================================================

make install
make install-commandmode
make install-config
install nagios-plugins yourself
cp -r /usr/local/nagios-plugins/libexec /usr/local/nagios/


===================apache httpd.conf insertion===================

ScriptAlias /nagios/cgi-bin /usr/local/nagios/sbin

<Directory "/usr/local/nagios/sbin">
    Options ExecCGI
    AllowOverride None
    Order allow,deny
    Allow from all
    AuthName "Nagios Access"
    AuthType Basic
    AuthUserFile /usr/local/nagios/etc/htpasswd.users
    Require valid-user
</Directory>

Alias /nagios /usr/local/nagios/share

<Directory "/usr/local/nagios/share">
    Options None
    AllowOverride None
    Order allow,deny
    Allow from all
    AuthName "Nagios Access"
    AuthType Basic
    AuthUserFile /usr/local/nagios/etc/htpasswd.users
    Require valid-user
</Directory>
=================================================================

/usr/local/apache/bin/htpasswd -c /usr/local/nagios/etc/htpasswd.users admin
/usr/local/apache/bin/htpasswd /usr/local/nagios/etc/htpasswd.users other user(without -c when add second user)
cp /usr/local/nagios/etc/*.cfg-sample /usr/local/nagios/etc/*.cfg

===================minimal.cfg modification======================

put # in front of services that appear in checkcommands.cfg and m
isccommands.cfg in minimal.cfg
=================================================================

/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

Total Warnings: 0
Total Errors:   0

/usr/local/nagios/bin/nagios -d /usr/local/nagios/etc/nagios.cfg