am not 100% sure, but if the drobo pro uses a basic usb connection, i like to think that usb should still work on a mac with official usb. (there might be some problems with macs that do not have usb, and only have firewire or thunderbolt convertors, but maybe one good test which may help in the meantime, especially if you are planning on getting elcapitan, could be the following?)
- to try installing a version of dashboard onto an Elcapitan computer (maybe a friend could bring his laptop round one time to help you), and either the same version as what you have now, or just the latest dashboard version.
- tweaking permissions or firewall settings to allow the dashboard application or services to run
- and then plugging in your drobo to see if it is recognised.
as far as i know, it should be either recognised or not, but definitaly do not format or initialise anything if a message pops up, though if in any doubt then it would be good to have a backup of your data first (especially if you do not have any backups etc)