How do I un-claim a Time Machine backup? I recently wiped my Time Capsule and started a new set of backups. After a couple of weeks, Time Machine reported that “to improve reliability”, it needed to start over—again. My understanding is that this is caused by a filesystem error so bad it can't be identified, let alone fixed, so one would have to start anew.

This is all very well, but there doesn't seem to be an option to start backing up again without erasing the existing backup image. I'd like to keep it around for a while.

Is there any way to un-claim a Time Machine backup?
I had this a long time ago, so I am not 100% sure that I remember the solution correctly, but I think it was rather simple:

Rename the existing backup image or tuck it away in a folder.