Orbstack can destroy your Time Machine backups

This has been an ongoing issue with Orbstack for almost a year now. It's a great project, but this issue is quite destructive.

Orbstack creates a 8TB sparse file disk image. If you have a Time Machine disk that is not formatted as APFS, Time Machine will interpret this as a full 8TB file, and it will happily prune all of your snapshots to try and make room for all 8TB. In my case, the resulted in almost six years of backups wiped out, and a Time Machine disk that cannot complete any backup now.

If you use a backup service like Backblaze, it will try to back up the entire 8TB as well, which causes additional problems with backup and restoration on their service.

There have been a few suggestions made on how this issue could be resolved, but nothing has been implemented.

The maintainers of Orbstack should not be harassed, but this issue definitely needs more eyes on it, to see if any better solutions could be found.