http://www.cyberciti.biz/faq/nmon-performance-analyzer-linux-server-tool/
# Get Root
sudo su
# Download NMON archive
cd /tmp
wget http://nmon.sourceforge.net/docs/MPG_nmon_for_Linux_14a_binaries.zip
# Install unzip if you don't have
yum install unzip
# Unzip archive
unzip MPG_nmon_for_Linux_14a_binaries.zip
# Copy nmon file
cp nmon_x86_64_centos5 /usr/local/bin/
chmod a+x /usr/local/bin/nmon_x86_64_centos5
# Create symbolic link
ln -s /usr/local/bin/nmon_x86_64_centos5 /usr/local/bin/nmon
# vim ~/.bashrc
alias nmon='. ~/.bashrc'
# . ~/.bashrc