WLS: Entropy setup on OL

I was getting some hanging, clearly related to entropy while trying to upgrade an EMCC instance from 13.2 to 13.3.

This note is about to check and increase the entropy on a OL6.9 compute.

#1 Verify the entropy values

cat /proc/sys/kernel/random/entropy_avail

Recommended value should be higher than 1000

#2 Install rng

yum install rng-utils

#3 Start the rng process

# rngd -r /dev/urandom -o /dev/random -t 1

This command can be moved on /etc/rc.local

#4 Verify that the entropy is increased:

cat /proc/sys/kernel/random/entropy_avail