转自： http://my.itwnik.com/how-to-increase-linux-kernel-entropy/
First of all you can check amount of entropy that you have
cat /proc/sys/kernel/random/entropy_avail.
To increase Linux kernel entropy you can run nice util called “rng-tools”.
yum install rng-tools
After installation you can try to start and get such error:
/etc/init.d/rngd start
Starting rngd: can’t open entropy source(tpm or intel/amd rng)
Maybe RNG device modules are not loaded[FAILED]
Please add extra options:
Edit /etc/sysconfig/rngd
EXTRAOPTIONS=”-r /dev/urandom”
Check your entropy again.
cat /proc/sys/kernel/random/entropy_avail