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
