Exim Entropy

While trying to get exim4 using TLS I noticed an odd problem. For some reason /dev/random was not generating a lot of output due to a lack of entropy. I do not fully understand the problem but it meant that exim4 was being blocked when generating the RSA key. I tried changing from a 2.4.32 kernel to a kernel and this seemed to generate more random data but it still wasn’t sufficient.
I resorted to editing my
commenting out the last line that deletes
I then ran
find / -type f | xargs cat > /dev/null
to generate a lot of noise on the system.
hal:~# swaks -a -tls -q HELO -s localhost -au harry
=== Trying localhost:25…
=== Connected to localhost.
EHLO hal.vm.bytemark.co.uk
<- 250-hal.vm.bytemark.co.uk Hello localhost []
<- 250-SIZE 52428800