Time Capsule Oddities


I have an Airport Time Capsule that is running as a Time Capsule only. Ever since I can remember, the status of this device has been “1.4 TB of 2 TB available”. However, my oldest backup is only from last November.

As an experiment, I turned off file sharing on the TC. Immediately the disc became unavailable to TM. A day later, no backups had occurred, so I turned file sharing back on. Voila, backups started immediately.

So there’s two things I don’t understand here:

  1. Why isn’t more of the disc used, and
  2. Why does turning off file sharing make the TC unavailable?


So I think this will come down to a particular time machine behaviour that I don’t have an actual answer to.

Does the time capsule keep an unlimited number of hourly backups until it meets disk pressure?

It’s possible, that you’ve been backup up long enough, and add sufficiently little over time, that you’ve found the natural ‘terminal size’ of your backup, because there will only ever be so many backups and older ones are flattened.

It could also be that you add relatively little data over time and so very few backups add extra data anyway.



You must be right. After adding the last big batch of photos, the status dropped to 1.38 TB available.