Drobo 4 Bay USB 3 as Time Machine

Hi everyone … hope you can help.

I’ve been using my Drobo 4 Bay USB 3 as Apple Time Machine Back Up. I think i set up Drobo correctly for Time Machine (64Tb).

I’m now running critically low on available hard drive space (4%) so the Drobo Red Light is on.

1 ) Will my Drobo automatically delete old back ups or do i now need to add a new bigger drive?

2 ) Are we likely to run into problems with long term comaptability now that Drobo seems to no longer be trading and updating?

Any help would be much appreciated.

Thanks to you all …