"The volume is the wrong format for a backup" when attempting to copy HFS Time Machine backup to new APFS disk

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Level 1

18 points

"The volume is the wrong format for a backup" when attempting to copy HFS Time Machine backup to new APFS disk

My existing Time Machine backup disk has run out of space. After several attempts to copy my existing 6TB HDD Time Machine to an 18TB HDD, both formatted in HFS GUID and repeatedly getting Error -36 with the copy failing after about 24 hours of copying, I researched and found that Apple recommend APFS for Time Machine from macOS10.13 upwards and that this is compatible with HDD, so I formatted the larger drive in APFS.

Despite all this advice and recommendations from Apple, it failed with an error as per screenshot attached. I really don't mind which format I use, or even if I have to revert to HFS for the larger HDD, but I surely cannot be the only person to want to copy their expanding Time Machine to a bigger disk. A while ago, I contacted Apple Tech support by phone, and they told me what I was trying to do was not possible, and that I should just start a new Time Machine backup from scratch. This I do not want to do, and lose the history of the past several years. Does the Users Brains Trust have a workaround?

Mac Pro, macOS 10.14

Posted on Jul 14, 2023 6:26 PM

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Answer 1

BDAqua

Level 10

250,253 points

Jul 14, 2023 7:27 PM in response to dwmusic

Have you opened Disc Utility, then in the view menu choose show all Devices, then chose the top left entry for the new External drive, then Format/Erase to APFS?

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Answer 2

dialabrain

Level 10

135,947 points

Jul 14, 2023 6:57 PM in response to dwmusic

dwmusic wrote:

A while ago, I contacted Apple Tech support by phone, and they told me what I was trying to do was not possible, and that I should just start a new Time Machine backup from scratch. This I do not want to do, and lose the history of the past several years. Does the Users Brains Trust have a workaround?

What you were told is correct. If you want to keep the old backups for some reason. Remove the drive from Time Machine Settings, Add the new drive and start a new backup. FWIW, Time Machine was never meant to be an archival system.

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Answer 3

dwmusic Author

Level 1

18 points

Jul 14, 2023 7:16 PM in response to dialabrain

OK, thank you. However, when I plugged the APFS formatted drive into the Mac Pro, Time Machine Preferences asked me if I was sure I wanted to erase the drive. After I clicked Yes, it went ahead and changed the format to HFS. Yet here Apple are saying "APFS or APFS Encrypted disks are the preferred format for a Time Machine backup disk." They also say APFS is compatible with macOS 10.13 and upwards. Any idea why this is not working?

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Answer 4

dialabrain

Level 10

135,947 points

Jul 14, 2023 7:21 PM in response to dwmusic

You're welcome. APFS is the preferred and actually only format for current versions of macOS. However, since you are running Mojave 10.14 it is a different story. Just follow the on screen instructions.

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Answer 5

dwmusic Author

Level 1

18 points

Jul 14, 2023 7:42 PM in response to BDAqua

Yes, thank you, that was how I formatted the 16TB HDD originally (using a MacBook Pro running Ventura), but when I plugged the external drive into my Mac Pro 2012,5 running High Sierra 10.13.6 and started Time Machine preferences, it reverted the format to HFS. I didn't try answering No to the 'Erase Disk?' question, as I assumed that would abort the Time Machine setup for a new disk.

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Answer 6

dwmusic Author

Level 1

18 points

Jul 14, 2023 7:46 PM in response to dialabrain

Actually, I am forced to run High Sierra 10.13.6 because Mojave is not compatable with acceleration on my NVIDIA graphics card for reasons I have never been able to garner from either Apple or NVIDIA. Why do you think that even though Apple are saying APFS works with macOS 10.13, that APFS is preferable for Time Machine, and that APFS is compatible with HDD's, this still won't work?

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Answer 7

dialabrain

Level 10

135,947 points

Jul 14, 2023 7:53 PM in response to dwmusic

See: https://en.wikipedia.org/wiki/Apple_File_System

"Performance on hard disk drives

Enumerating files, and any inode metadata in general, is much slower on APFS when it is located on a hard disk drive. This is because instead of storing metadata at a fixed location like HFS+ does, APFS stores them alongside the actual file data. This fragmentation of metadata means more seeks are performed when listing files, acceptable for SSDs but not HDDs."

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Answer 8

dialabrain

Level 10

135,947 points

Jul 14, 2023 7:25 PM in response to dwmusic

Just to add, HFS+ works better with a HDD, APFS with SSDs.

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Answer 9

dialabrain

Level 10

135,947 points

Jul 14, 2023 7:45 PM in response to dwmusic

Sorry, I assumed you were running 10.14 as it says in your signature. On High Sierra, you have to let it format as HFS+.

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Answer 10

dialabrain

Level 10

135,947 points

Jul 14, 2023 7:59 PM in response to dwmusic

What I am am trying to say is you're better off with a HFS+ formatted Time Machine HDD drive. In any case you cannot transfer the Time Machine files over from the Ventura formatted drive.

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