Migrating Time Machine to a new drive?

Is it possible, and if so, how? I have a 2TB SSD for my TM drive. It is now full, which I suppose is understandable as I have about 1.3 TB of data internally, and unfortunately when I migrated to a new Mac Studio and adopted the TB drive from my prior computer (tmutil inheritbackup) TM somehow felt the need to copy over a large amount of my data again.

I was thinking the ideal solution would be to copy the entire TM drive over to an external (spinning) drive and then reformat the SSD and restart TM to it. I want to copy over the TM data so that if I find that I need to restore something that was removed/deleted, I can hook up the copy of my current TM drive and browse it in TM.

I believe CCC specifically states they do not copy TM drives, but maybe that is outdated?

The tmutil command (perhaps surprisingly, perhaps not) does not have an option to copy a TM drive.

Any help appreciated.

This topic has come up a few times previously and it is something I’ve had a fight with myself. Unfortunately I’ve not as yet found a way to copy Time Machine backups between disks. Straight forward copies, using Rsync, I think I’ve even tried creating tar archives - all of it just falls over in a heap at some point.

If you’re aiming to migrate to a new, larger TM disk; then the option would seem to be just start a new TM back up on the new disk.

If you want to continue using the current disk then, when it really is full, TM should automatically start removing older stuff to free up space.

In this post the developer says SuperDuper can clone a TM volume. Whether it can recreate that volume on another drive is not mentioned. He’s very responsive to questions though.

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Although TM is very useful, it is also still very fragile. Despite adopting the previous TM backup on the new machine, all of my data was copied over again, filling the drive. TM kept failing because there was no space on the drive; it did not delete the oldest backups.

I had to give up and just formatted the drive and started a new TM backup.

I do have a second TM of the old machine on my Synology (I do two TMs, one to an attached SD and one to my Synology) and a clone on the Synology as well, plus BackBlaze and ARQ, so I do have all of the files in multiple places, so there was no risk of data loss. Still, not very elegant.

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I haven’t used this, but someone might find it helpful.
It’s a utility for TimeMachine that gives more info and capabilities than the macOS TimeMachine interface.


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I’ve done it this way a few times, most recently early this year.

TM is touchy. Might I suggest just keep the old drive (just in case you might need something) and simply start fresh with a new drive?


That article is from 2013, before APFS, and the discs are formatted HFS+. I’m not sure it will work with APFS.

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Good point. If the existing TM disk is formatted APFS, this won’t work. Some discussion about it here.

It works with HFS+, which is what I use for my Time Machine external (spinning) disks, because APFS and spinning disks don’t work well together

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It seems that migrating TM to a new drive is not something than can be readily done, nor is it reliable to adopt a TM backup from one Mac to another. I tried the latter and it failed - although the TM backup was adopted, entirely new copies of about 500GB of files were made, which is certainly not optimal.

The major stumbling block for me to just archiving the old drive and starting fresh is that the old drive is a 2TB SSD, and they are not cheap. Since I have BackBlaze, Arq, CCC and TM copies of everything elsewhere, it was just simpler to reformat the drive and start over, knowing I can always pull historical copies from one of those 4 locations if needed.

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I have done this successfully but not with APFS. I’m grateful for your observation, since now I don’t have to try it and fail myself.

A 2TB Samsung T7 is $200. Granted, it’s not $1.98, but $200 isn’t that bad. But there’s nothing wrong with the way you did it either.

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