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I had a pretty hard time getting this to work, so I'll share the steps I went through. Start by backing up the node in the distributed system that you want to restore (to a single node): > mnesia:backup("/path/to/backup"). Make sure the following adaptation of change_node_name is available on the node you want to restore to: -module(move_backup). -export([set_node_name/4]). set_node_name(From, To, Source, Target) -> Switch = fun (Nodes) -> case lists:member(From, Nodes) of true -> [To]; false -> [] end end, Convert = fun({schema, db_nodes, Nodes}, Acc) -> {[{schema, db_nodes, 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, Switch(Val)}; false-> {Key, Val} end end, {[{schema, Tab, lists:map(OptSwitch, CreateList)}], Acc}; (Other, Acc) -> {[Other], Acc} end, mnesia:traverse_backup(Source, Target, Convert, switched). Convert the backup: > move_backup:set_node_name('before@host', 'after@host', "/path/to/backup", "/path_to_backup_converted"). I'm going to assume that the new node is completely empty (if this is not the case, you might want to change the default_op argument). There are two options, one for a live restore: > mnesia:restore("/path/to/backup_converted", [{default_op, recreate_tables}]). which is great but might use a lot of memory if you have a large database (mine was ~10GB so this caused an out of memory exception). The alternative is to install a fallback, and restart your shell: > mnesia:install_fallback("/path/to/backup_converted"). > q(). then when you restart the shell (assuming you're using the right node name) it will import the full database. |