How to move time machine backup to a larger drive

APFS formatted Time Machine drives cannot be copied anywhere with any Apple or current third-party tool. One performs one last backup and properly ejects the drive. Then educate Time Machine that you are now using a new drive, not the old one, and perform a first full backup to the new drive.

I take an Avery address label and stick it on the previous Time Machine drive. On it, I write the last version of macOS backed up to it, and the date/time of the last backup. I do not encrypt my Time Machine backups, but if I did, I would also write the password on that drive label because one is bound to forget it otherwise. Then I use Scotch tape over the label to protect the writing on it and keep the label on the drive that is then set aside in a safe location.

You cannot copy a TM backup to another drive.

The best you can do is start a brand new TM backup on your new drive. Preferably that has at least twice the capacity of the Mac startup drive you want to back up.

As for the now-full old TM backup drive, you can either put it aside as a data archive, or you can erase it and use it for other things, perhaps even as a second TM backup drive. Backup redundancy is a good thing.

In the past I have successfully copied TM backups to other disks using SuperDuper. It erases the target volume then copies the entire TM backup – the copies were always functional as a TM backups. Carbon Copy Cloner, my favourite, I know doesn't.

So I was intrigued whether I could do with my Sequoia TM backup.

So I arranged a partition on another disk and ran SuperDuper. It took 5.5h to copy the 295GB.

I plugged this disk containing TM copy into my MI running Sequoia and selected as a TM backup. It recognised it and I was able to access the files via starwars. I then selected ‘backup now’ and that worked just fine too – though slower than normal.

Now some caveats. I had arranged the original Sequoia TM disk to be formatted as Mac Extended Journaled not APFS.

I copied the Sequoia TM disk attached to my iMac19,2 (running Mojave) as that’s where my copy of SuperDuper resided.

The end result was that I was able to copy a functional Sequoia TM to another hard drive but I am guessing that’s because the hard drive format was Mac Extended Journaled not APFS but I can't test that.

swephotos wrote:

Thanks everyone! I accept that this is not possible, but I am curious to know why? Thanks again.

It is complicated technically, but both CCC and SuperDuper have explained why this no longer works RELIABLY (you may see anecdotal claims that someone did manage to copy an older formatted Time Machine backup disk but neither vendor supports it and both recommend against it) somewhere on their support areas of their web sites. Time Machine relies on special links on the backup disk to enable it to maintain incremental backups while also being able to recreate an entire drive from back in time. Those links have some hardware specific elements that stop working when transferred to a different physical drive. This is especially true for APFS drives, it might be only sometimes true for HFS+ (older format) drives.

I never try to copy or clone such backups because a RELIABLE backup is the most important thing for me, not saving a few dollars on a new drive. Also, these drives all do wear out eventually so adding a new drive (while keeping the old one as an archive of sorts) after some ~ years is not a bad thing.

As both of my colleagues have mentioned - forget that idea

To add, not even using a dedicated Cloning software like Carbon Copy Cloner can clone the TM Backup Drive to another External Drive

Can I use CCC to copy a Time Machine backup?

" No. Copying a Time Machine backup volume with anything other than the Finder is not supported (by us, nor Apple); CCC specifically disallows copying anything to or from a Time Machine backup volume. Apple does not document a procedure for making copies of Time Machine volumes."

+1

You can not copy the Time Machine backups.

Set the old Time Machine drive aside and start new Time Machine backups on the new drive.

If you have deleted files from your Mac that you need from the old Time Machine backup drive..?

Then you should restore those files back to your Mac, before wiping and repurposing the old drive.

Hi Swephotos

It is possible to copy a TM backup for new macs but probably only if formatted as HFS which yours probably wasn’t.

It is one reason I made sure that the TM backup for my M1 sequoia was formatted HFS. It also makes it readable on my Mojave iMac (and presumable other MacOSs), so much more flexible

Although the net gives different methods for doing that I formatted the drive as HFS and did TM backup of Mojave from Imac 19.2. Then took that disk to the M1 silicon and selected the drive as a TM backup. Then did the TM for the M1. As there was already a TM backup it did not reformat the disk. Once finished I deleted the Mojave Backups.backupdb. M1 has continued to do functional TM backups which I can copy to other disks and read on other Macs.

So there are ways around being told by organisations what is good for one.

The point being, that TM Backup Utility is Expecting the Destination Drive be Formatted APFS

What you have done may worked as a Work Around which I personally would not expect to work for too much longer

swephotos wrote:

Thanks everyone! I accept that this is not possible, but I am curious to know why?

It isn't economically justifiable. There aren't enough people who would be interested in doing it to make it worth trying to implement. These days, Apple is really struggling to implement the features that are worth doing.

Technically, anything is possible, if you have enough money to pay for it. But when your vendor is as wealthy as Apple, it costs a whole lot more to bribe them into doing the work.