Sharing a repository between multiple clients

Obnam lets you backup several computers to the same repository. Each client is identified by a name, which defaults to the system hostname: the name you get when you run the hostname command. You can also set the name explicitly, using the --client-name setting in Obnam.

All the clients sharing a repository share the file content data (the chunks), and can de-duplicate across clients. Each client has its own backup generations, and those are fully independent from other clients. You can, for example, forget any generations you want for one client, and it doesn't affect the generations or any backed up data for any other client.

Obnam takes care of locking automatically so you can run Obnam on each client without having to arrange it so that you only run it on one client at a time.

A caveat of sharing a repository is that any client has access to all chunks, and can delete any other client from the repository. This means you should only share a repository amongst clients in the same security domain: all clients should be trusted equally. If one client gets hacked, then the intruder has access to all the data in the repository, and can delete the backups of all the clients using that repository.

To share a repository amongst clients you need to do the following:

That's all.

To see what clients are using a repository, use this:

obnam clients

There is currently no way to remove a client from a repository, unless you're using encryption. This is to be considered a bug in Obnam, and will be fixed at a future time. After that, a time machine will be developed so that this paragraph will have never existed.