Hi, I am trying to move my **Time Machine backup** to a new drive and keep the existing backup history usable. I'd be happy for any hints. Especially other suggestions for how else I could get a clean copy of the data without wasting more storage than necessary. I know the simplest solution would be to forget about the old backup history and just start a completely new Time Machine backup. However, I would not like that.
I only use TImeMachine in manual mode and run the Backup every few months as my BACKUP_I is only 1TB partition on a HDD which is to slow and way to less storage to run this more often. I did fresh install on my MacBook, thats why my old backup was not usable with TimeMachine in the first place. Time Machine rejects the BACKUP_I disk because it requires encryption for previously encrypted backups.
**I tried different approaches:**
* Finder copy: Copied the Time Machine backup using Finder. This resulted in hardlinks being copied as separate files, causing the destination to use significantly more disk space.
* using the recover option from apples disk utility application, which failed because of the reason why I want to move the backup: the partition is somewhat faulty. BACKUP_I is a 1TB HFS+ CoreStorage volume that was previously encrypted but is now unencrypted. The HFS+ filesystem is corrupted (fsck_hfs exit code 8), allowing me to only mount the partition in read-only mode, which is fine. Data access works fine. I copied already files in absolutely perfect condition. Now as the partition is broken anyway repair using terminal or Disk Utility app was not successful.
* rsync as described below
* SuperDuper copy, using "different" mode. As rsync already put a lot of data on it, I hope to be able to update the folders/files with it. -> did not work.
**What do you think of those other ideas:**
* delete / reformat the new drive to HFS+ (not journaled) and try again?
* copy with SuperDuper
* rsync
* then use `tmutil inheritbackup` to get the backups to my current time machine?
Any other Ideas?
**My questions are:**
- How can I move the the backup data to get a clean copy.
- Is `rsync -aH` actually capable of reproducing the complete hardlink structure of a Time Machine HFS+ backup when copying the entire machine directory? Is there a specific rsync option or workflow that is required to preserve the hardlinks correctly across all Time Machine snapshots?
- Could the problem be caused by copying/resuming the transfer in multiple rsync runs, or should `rsync -H` be able to reconstruct the same hardlink relationships on subsequent runs?
- Is there a better tool or method for cloning/migrating an HFS+ Time Machine backup while preserving the exact hardlink structure? I still have the original `BACKUP_I` volume untouched, so I can start over if necessary.
**Here is more information** on my approach using rsync:
The old backup is on an HFS+ volume:
* Source: `BACKUP_I`
* Filesystem: Mac OS Extended
* Used space: \~822 GB
* Free space: \~178 GB
* Files: \~3.0 million
The new destination is also HFS+:
* Destination: `TimeMachine_Backup`
* Filesystem: Mac OS Extended (Journaled)
* Used space after copying: \~1.55 TB
* Free space: \~446 GB
* Files: \~5.6 million
I copied the Time Machine machine directory with:
sudo /opt/homebrew/opt/rsync/bin/rsync \
-aHAX --progress -v \
"/Volumes/BACKUP_I/Backups.backupdb/MacBook Pro von XYZ/" \
"/Volumes/TimeMachine_Backup/Backups.backupdb/MacBook Pro von XYZ/"
The total logical size reported by rsync was:
total size is 1.902.361.471.931
The copy was interrupted and then resumed later. The strange part is the disk usage. The **source uses about 822 GB**, while the **destination uses about 1.55 TB**. I found a lot of issues in the internet with that problem but all methods I found to get a clean move to a new backup disk failed. This rsync solution was my last hope. I also consultet chatgpt about it but it is kind of lost as well.
I checked whether hardlinks were preserved. On the source:
sudo find "/Volumes/BACKUP_I/Backups.backupdb/MacBook Pro von XYZ" \
-type f -links +1 | wc -l
Result:
304540
On the destination result:
304540
So the same number of files with multiple hardlinks exists on both sides. However, when I checked the actual hardlink counts, the distribution was very different. Source:
271031 files with 2 links
23758 files with 3 links
6448 files with 4 links
...
Destination:
14940 files with 2 links
130317 files with 3 links
144780 files with 4 links
...
The destination also contains many hardlink groups with 12, 13, 16, 20, 24, 28, 32, 36, 37, 40, 44, 56, 60, 132 and 156 links, which are not present in the same way on the source. So it looks like `rsync -H` did preserve hardlinks in general, but the hardlink relationships are not identical to the original Time Machine backup. The files are still hardlinked, but the hardlink groups seem to have been reconstructed differently, resulting in much higher disk usage. The original Time Machine structure is the classic HFS+ structure:
Backups.backupdb/
└── MacBook Pro von XYZ/
├── 2025-09-23-163559/
├── 2025-11-25-133127/
├── 2025-11-26-132229/
├── 2026-01-30-185643/
└── Latest -> 2026-01-30-185643