Switch from Single DHCP to Master-Slave DHCP setup

[Gregory Sloop]

I've recently setup DHCP+DNS [DDNS] on a single master server.

I'm about to turn the switch on a master + slave DHCP updating the
master DNS, [with the second/slave DHCP server having a slave DNS
server getting updates from the master.]

[i.e. DHCP + Single master DNS + Slave DNS]

Ignoring the DNS configuration - is there anything special I need to
do when I start load-balancing the DHCP servers, or do I just change
the configs on both machines appropriately and the single will pass
off what needs passing to the new slave and load balancing happens
"automagically?" [i.e. Do I need to copy the dhcpd.leases file or
other steps.]

I've done some searches on this, but haven't found anything - I'm glad
to be pointed in the right direction. I'd assume this discussion has
occurred many times before, but I can't find it.

(My plan is to turn on the Slave DHCP, and once it's stable and working
fine, then turn on Master/Slave DNS - to do everything just one step
at a time.)

TIA
-Greg