dns

# cd /etc/bind

Add these lines to your zone declaration in named.conf.local:

inline-signing yes;
auto-dnssec maintain;

Then:

# mkdir /etc/bind/zones
# cd /etc/bind/zones

  Here, create your zone file: example.com.db

This command synchronizes all current setting with zone file, and also removes the journal (jnl) file:

# rndc sync -clean