I'm not sure why you're being down voted.
haveged is an absolute essential for all servers
haveged is an absolute essential for all servers
that means it will block when it estimates that you have "used up" all of the available entropy
you can check how many bits of entropy your kernel thinks are available easily
cat /proc/sys/kernel/random/entropy_avail
edit: i should have mentioned that there is some reason to argue against this behaviour but that doesn't change the usefulness of haveged for existing systems
The random(4) manpage is unfortunately exceptionally misleading, and has sadly led to a small but non-zero numbers of products that try to use /dev/random rather than /dev/urandom.
Sadly, gpg --gen-key doesn't even give you this option - but that's (as noted above) another flaw in GPG.