I ran into this before Christmas ( had a 500gb Time Capsule ) and the solution for me, at least, was to have my family buy a bigger one, since they have no backup tendencies at all, and automation is key for them. I know the TC has an archive feature; possibly you could hook up the Drobo to the TC, archive to it, and wipe the TC clean? I'm not sure if that's the best solution, but it's about the only one I can think of right now.
hmmm, that sounds like a pretty good idea but my iMac is 1 TB, and the 2 MacBooks are about 500GB total, so the backup drive (the TC) is smaller than the total of the 3 computers. I was wondering if there's a way I can expand the memory w/ the Drobo.... (one can dream, right?) ;)
I don't you can "expand" the space to the Drobo, but if you had a Drobo hooked up to your Time Capsule you could have some computers back up to the Time Capsule and some to the Drobo.
You can add a USB hard drive to a Time Capsule and expand storage onto it. Also, I've wiped and restarted my backup process at the office. If you aren't worried about multiple file states and just want a backup in case of HD failure, this will give you space back.
Thanks, tpaulding & justus. I know you can add an external HD via usb to the Time Capsule but I was under the impression this would not add space to the Time Machine backups. Is this incorrect?