Purging old Time Machine backups?

[DanL]

I've migrated my Time Machine backups to an external drive. In the interest of cleaning up my internal drive, how do I purge the huge storage space taken up on my internal drive by Time Machine? Is this supposed to happen automatically when I change the Time Machine disk?

 

[MightyGem]

I didn't know that you could do a TM backup to your internal drive. I mean, what would be the point? It's certainly not an option in TM Preferences.

 

[DanL]

If you don't select an external drive, that's where it's going to put it. The point of an internal backup would be in case you accidentally delete stuff. Obviously if the whole internal disk goes south, then you're screwed in that case.

 

[oldscribe]

Hi,

Possibly this article may help re purging local backups.

https://www.howtogeek.com/212207/ho...d-by-time-machines-local-backups-on-your-mac/

 

[DanL]

Yes, in principle, that's a great idea. But it doesn't work. In Monterey. When I do sudo tmutil disablelocal , I get back the error message disablelocal: Unrecognized verb.

 

[MightyGem]

You don't have to worry about local backups taking up "huge space":

About Time Machine local snapshots – Apple Support (UK)

Time Machine lets you restore files from local snapshots of the files on your Mac, even when your Time Machine backup disc isn't available.

support.apple.com

 

[DanL]

Yes, I think the point is that Time Machine space is "expendable", meaning that if you need the space, the oldest TM snapshots will just get killed off. But what I'd like to do is put the TM backup on an external drive that is devoted to TM, so I always know how much is available for TM. My TM external drive will ALWAYS be available. But while TM keeps track of new stuff incrementally via "snapshots", there HAS TO BE one full backup on file to increment to if you want to fully restore a system. That is, a pile of snapshots do not constitute a whole system.

 

[MightyGem]

I think that when you did the TM backup to the external drive, it would have taken all the incremental with it.

 

[DanL]

It seems that it used to be that you could actually set limits on Time Machine storage space. When it hit those limits, is would start erasing. That was true before 10.13. Now, nope, no can do. Why does Apple keep removing handy stuff? That option ought to be part of the Time Machine setup pane.