This is a standard approach for setting up DNS. Two DNS servers would be considered the minimum.
Usually you would nominate one as the master of the zone, and one as the slave.
The master config would look something like this:
zone "example.com" { type master; allow-transfer { <slave IP>; }; file "/etc/bind/pri/db.domain"; }; And the slave would look something like this:
zone "example.com" { type slave; masters { <master ip>;}; file "/etc/bind/sec/db.domain"; }; The slave will take updates from the master, so you only need to update the zone on the master and it will get copied to the slave.