Time Machine: Reformatting external drive that has TM backups, without losing the backups?

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Time Machine: Reformatting external drive that has TM backups, without losing the backups?

Hello,

I have a WD external drive (2TB) that has two partitions:

APFS case-sensitive (1 TB) for time machine
Mac OS Extended Journaled (1 TB) for my personal data use

Just bought a LaCie external drive (5 TB) which I want to use solely for personal data. I already transfered personal data from WD to LaCie.

On WD, I'd like to undo the partitions and have the whole drive dedicated to Time Machine.

I'd simply manually transfer TM backups from WD to LaCie, then reformat the WD drive, then move back the TM backups to WD drive.

But will Time Machine like it? Is there a better way?

On a side note, I've naively manually deleted the oldest TM backup on WD's drive. I am now thinking I basically screwed the 11 following backups because of symlinks, did I?

Thank you for your help!

OSX: Ventura 13.2.1

MacBook Pro 13″

Posted on Jun 13, 2023 6:50 AM

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Answer 1

Top-ranking reply

etresoft

Level 9

50,614 points

Jun 13, 2023 7:25 AM in response to Megalo-XVII

Megalo-XVII wrote:

But will Time Machine like it?

Nope.

Is there a better way?

Yep. Erase the hard drive and set it up as a new Time Machine backup. Make sure to enable encryption.

On a side note, I've naively manually deleted the oldest TM backup on WD's drive. I am now thinking I basically screwed the 11 following backups because of symlinks, did I?

Not necessarily because of symlinks. Time Machine doesn't use symlinks. It uses structures far more esoteric. But generally speaking Time Machine doesn't like people messing with its internals. No software does.

Time Machine is a backup. It works best the less you mess with it. It is not an archive. If you delete files, they will eventually be deleted from your backup too. Sometimes people try to cling so hard onto their backups from many years past. Don't do that. If the backup flakes out, erase the drive and start a fresh one. If you are concerned about not having a backup during this period, get another drive and start another backup. You can have as many backup drives as you want. Do you ever hear anyone complaining about having too many backups?

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Answer 2

Jun 13, 2023 8:31 AM in response to Megalo-XVII

Even if you go to the trouble to temporarily copy the existing Time Machine backup file over to another hard drive.....before you erase the WD drive.......when you move the copy of the Time Machine backup drive back over to the WD drive, Time Machine will not continue to back up to the existing file.

Time Machine will start all over with a new complete backup of your Mac and work forward from there. So, you will have two different Time Machine backup files on the WD drive.

Do you really need backups from weeks, months and even years going back in time? If not, move the other Mac OS Extended (Journaled) data over to another hard drive, then simply erase the WD drive, remove the partitions and start over again with a new Time Machine backup of your Mac.

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