Copying Time Machine backup, destination takes more than original size, are hardlinks being expanded?

Solution 1:

If you are using an entire drive for time machine backup, I would suggest using Carbon Copy Cloner latest version with block-to-block copy. I have seen people use Disk Utility for this but I haven't got this to work.

As noted in this answer CCC does not work for TM backups now (since BigSur?) see CCC site

Solution 2:

Use rsync. rsync is included in MacOS X, it's widely recognised in the unix world and it can be used locally and on the network and can preserve hardlinks, attributes and permissions. Check the manual page for more information, IMHO this should work:

rsync -avHE /Volumes/Source/ /Volumes/Destination/

(archive, verbose, preserve hardlinks, preserve extended attributes).

Solution 3:

Starting from January 2020, CCC is not allowing clone tasks for Time Machine volumes, see this official docs: https://bombich.com/kb/ccc5/can-i-use-carbon-copy-cloner-clone-time-machine-backup

However another application SuperDuper! does the trick. It's free for tasks like a simple clone. Make sure to select "Backup - all files" option after setting the source and destination partitions.

It took 11 hours to move 900GB of data to a new drive, but it worked really well under macOS Big Sur. I've already finished my first new backup tasks to the new drive.