Does anyone know how the Drobo creates a Time Machine share and/or the sparsebundle on it?
I don’t think it does that locally. I think the Mac client creates it once the TM-enabled share is mounted.
Do you know what “TM enabled” means wrt to a Share? Is it just a share with a quota?
From a configuration point-of-view, it is just a flag that you put on the share definition in the netatalkd configuration files. Nothing more.
I assume that the flag just instructs the netatalk daemon to tell the Mac clients that whatever special file access API they need is available on that share.
The definition of the quota is not mandatory, btw. It is just a very good idea, since the Mac clients seem to be dumb enough to just assume that they are free to take as much place as they can unless the underlying filesystem blocks them…
Sorry for the late answer, somehow I got my account autobanned.
To answer your question: yes, support for TimeMachine is just a flag on the definition of a share. The quota definition is just another option, too.