If you need to change all of your dns servers through DirectAdmin one by one, it's easier to use perl to do a regex (regular expression) to do the replace for us with one command. To do this, you can run the following. (replace the bold items with your own)
cd /usr/local/directadmin/data/users perl -pi -e 's/ns1.old.com/ns1.new.com/' */user.conf perl -pi -e 's/ns2.old.com/ns2.new.com/' */user.conf perl -pi -e 's/ns1.old.com/ns1.new.com/' */reseller.conf perl -pi -e 's/ns2.old.com/ns2.new.com/' */reseller.conf cd /var/named #(or whatever the path to your *.db files is, eg: /etc/bind, /etc/named) perl -pi -e 's/ns1.old.com/ns1.new.com/' *.db perl -pi -e 's/ns2.old.com/ns2.new.com/' *.db