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copied!<p>I don't think this can be done online on a single node(anyone?), but it is possible to do via a backup/restore in addition to running two nodes and adding table copies. In the <a href="http://erlang.org/doc/apps/mnesia/part_frame.html" rel="noreferrer">Mnesia User's guide</a> section 6.9.1 you'll find some code that uses mnesia:traverse_backup to alter the node names in the schema table (Shown below) in an mnesia backup file. The module name you should probably use is <code>mnesia_backup</code>.</p> <p>With this code you'll need to:</p> <pre><code>%% On mypl@machine1 mnesia:backup("/path/to/mnesia.backup"). change_node_name(mnesia_backup, mypl@machine1, mypl@machine2, "/path/to/mnesia.backup", "/path/to/new.mnesia.backup"). %% On mypl@machine2 mnesia:restore("/path/to/new.mnesia.backup", []). </code></pre> <p>I'm not sure if you need to create the schema first on <code>mypl@machine2</code>.</p> <p>The change node name code from the user's guide:</p> <pre><code>change_node_name(Mod, From, To, Source, Target) -> Switch = fun(Node) when Node == From -> To; (Node) when Node == To -> throw({error, already_exists}); (Node) -> Node end, Convert = fun({schema, db_nodes, Nodes}, Acc) -> {[{schema, db_nodes, lists:map(Switch,Nodes)}], Acc}; ({schema, version, Version}, Acc) -> {[{schema, version, Version}], Acc}; ({schema, cookie, Cookie}, Acc) -> {[{schema, cookie, Cookie}], Acc}; ({schema, Tab, CreateList}, Acc) -> Keys = [ram_copies, disc_copies, disc_only_copies], OptSwitch = fun({Key, Val}) -> case lists:member(Key, Keys) of true -> {Key, lists:map(Switch, Val)}; false-> {Key, Val} end end, {[{schema, Tab, lists:map(OptSwitch, CreateList)}], Acc}; (Other, Acc) -> {[Other], Acc} end, mnesia:traverse_backup(Source, Mod, Target, Mod, Convert, switched). </code></pre>

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