TM Backup explained

[MacInWin]

Great article by Howard on how TM works now using snapshots:

What can you do with Time Machine backups on APFS?

When Time Machine makes its backups to APFS storage, just what can and can’t you do? How can you prevent large temporary files from stealing space on storage?

eclecticlight.co

 

[IWT]

Thank you for posting this link, Jake.

The whole subject of Time Machine BUs using APFS (case sensitive, BTW) has an element of bewilderment and I'm glad to accept my ignorance and let them get on with things. Like you - I think - I use TimeMachineEditor to control my BUs.

I don't "seem" to be plagued with too many snapshots on the iMac and I've plenty unused space on the two TM EHDs.

I also use CCC which I BU once a day - manually. And copy "Documents" to another EHD every couple of weeks. And so on.............

I fear that some of the options which the article refers to might cause some people to "tinker" with TM via Finder. Perhaps it's best to trust Apple to do the business for us?

Thank again.

Ian

 

[MacInWin]

Ian, the article explains a phenomenon I've seen people complain about--you have to use Finder to delete TM backups. Before, you deleted a TM backup from WITHIN Time Machine, so that it could rebuild the hard links to older, unchanged files. But now, using snapshots, the deletion has been moved to Finder. It also appears that TM won't purge a drive of older backups when it runs out of room any more. If you get the message that there isn't enough room, you have to use Finder to delete the oldest to make space yourself. But you don't have to wipe ALL of them out, just make room. Of course, you'll need to continue to do that as the next backup comes along, and the next, and, and, and...

At the same time, you cannot delete an individual file in the snapshots, either. I've seen folks want to do that for some reason. Technically, you cannot delete ANY file from ANY snapshot, but it comes up in TM more than most places.

Yes, I use TME to manage my backups and I end up with two snapshots on my internal drive, at the two times each day I make the backups.

I use CCC, and Chronosync to make other copies/backups/archives of parts and pieces of my system, too. I have had my internal drive AND backup drive fail on the same day, so I know to make more than one backup in more than one place for things I don't want to lose.

 

[IWT]

Thank you. As always, a clear appraisal of the relevant facts. I wish I had your knowledge. Good on you.

Ian

 

[ferrarr]

I used to go into TM and delete files/folders when I was running low on space. I would choose the option to delete all backups Of course I would only do that after I went through the folders and made sure there was nothing in the backups that was no longer on my current folder.

 

[MacInWin]

Bob, that was possible under the previous approach to backups, before APFS and snapshots. Now, a snapshot is unchangeable, but can be deleted. So, you can no longer pick and choose what to delete from any given backup, you can only delete the whole backup. Read the linked article, Howard did a great job explaining what you can and can't do.

 

[ferrarr]

Jake, I realized that a few months ago when I did my clean install of Monterey. And I was unable to use either of my 2 previous TM backups to restore from. Now I'm only using 1 TM backup, and I will use the 2nd one when the 1st one is full. I may not even need the 2nd one anymore.