erl -sname one -config one.config
erl -sname two -config two.config

(one@media)1> ddict:create_schema().
starting mnesia on two@media
{atomic,ok}
(one@media)2> mnesia:info().
...
running db nodes   = [two@media,one@media]
disc_copies        = [rec,schema]
[{one@media,disc_copies},{two@media,disc_copies}] = [schema,rec]
...
ok