Entropy on linux

Introduction
How to check entropy level:

watch -n1 cat /proc/sys/kernel/random/entropy_avail

If the value is to low (around 100) install haveged daemon

How to install haveged on Linux

Debian

apt-get install haveged

CentOS
haveged daemon is available for CentOS via EPEL repository.
First, we download and import the GPG keys for EPEL software packages:

wget http://ftp.riken.jp/Linux/fedora/epel/RPM-GPG-KEY-EPEL-6
rpm --import RPM-GPG-KEY-EPEL-6
rm -f RPM-GPG-KEY-EPEL-6

Download EPEL repository for 32-bit CentOS

wget http://dl.fedoraproject.org/pub/epel/6/i386/epel-release-6-7.noarch.rpm

Install EPEL repository on 32-bit CentOS

rpm -ivh epel-release-6-7.noarch.rpm

You can start install and use EPEL the repository to install the software packages, input yum command like follows:

yum --enablerepo=epel install haveged

SysAdmin