I have timemachine backing up to two external USB disks. This mostly works OK: backups seem to alternate between disks. However, sometimes df shows a long list of what are apparently temporary backups:

com.apple.TimeMachine.2022-01-07-203345.backup@/dev/disk5s2 5860123488 1964009216 3690873144    35% 1738342 18454365720    0%   /Volumes/.timemachine/32B7D235-F075-45C3-B736-B154B66AEBFC/2022-01-07-203345.backup
com.apple.TimeMachine.2021-08-09-204352.backup@/dev/disk4s2 7813625776 1777908552 4806526336    28% 1370278 24032631680    0%   /Volumes/.timemachine/B4F9590F-C6D6-433B-AC54-119AA2F6A753/2021-08-09-204352.backup

(there are 80 lines like this now, split between the two disks (/dev/disk4s2 and /dev/disk5s2).

The number of these seems to go up and down over time, but I don't know what changes. My guess is that they are hourly backups that couldn't finish for whatever reason, and they stay around until that hourly backup would have normally been deleted. But some of them have dates going back 6 months or so; maybe those are the hourlies that were kept as a daily, then the daily kept as a weekly, and so forth?

Is there a way to get these volumes written out or cleaned up, so that they don't clutter my df results? Is there a latent problem with my backups that I need to address before I need to recover something?

1 Answer 1


I observe the same with 11.6.2 and I have the suspicion that from time to time the backup device cannot be mounted because of all this rubbish which seems to act like broken mount points. Somewhere I read that fdisk sees these as uncleanly unmounted drives and thus prevents a new mount of the backup drive. So far only reboot helps.

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    – Community Bot
    Jan 13, 2022 at 14:02
  • Thanks for the answer...I rebooted (with a full check of all filesystems in Recovery mode), and all but one of the mounts went away, but they're back now...and in greater numbers! It sure would be nice to know what causes this, whether it indicates data is at risk, and how to clean up or prevent it!
    – Dave M.
    Jan 17, 2022 at 22:33
  • 12.6.2: Running Disk First-Aid in Recovery mode fixed the accumulation of broken mount points; now, they only appear transiently as time-machine works in the background.
    – trashgod
    Jan 23, 2023 at 23:32

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