[CentOS] EL9 says: pcp-pmie[2870]: Low random number entropy available 15.6%

Hi,

I've discovered an issue which I don't understand. On a new test install of EL9 I saw this message in the logs:

Mar 01 08:09:18 <hostname> pcp-pmie[2870]: Low random number entropy available 15.6%avail@beta.corp.invoca.ch

This is on a 64 core "AMD Opteron(tm) Processor 6282 SE" server but I also got the same low entropy on an EL9 KVM guest running on a "AMD EPYC 7601" server.

After a lot of searching the net I understand that rng has been reworked in 5.x kernels and /proc/sys/kernel/random/entropy_avail reaches only 256 in default configurations. But why does it go too low on a test system with almost not load?

Is this an issue with AMD CPUs or does it also happen on other systems?

Thanks for any insights, Simon