Moving Time Machine backup to new drive

Hi there,

So I'm writing this for future use of the community if someone has the same issues I had and cannot find a straightforward solution.

The simple task at hand was to move the time machine backups from an external drive (Old drive) to a new bigger drive (New drive). My old drive with 3TB was getting full and I decided to buy a new one with 8Tb and re-purpose Old drive to other tasks and use new drive also for backup of a new Macbook Air. At the time I started the migration, the backup folder had 2.9 TB.

Apple has a help topic that describes their preferred solution (Time Machine: How to transfer backups from a current backup drive to a new backup drive - Apple Support) which consists in:

- erase New drive

- drag backup folder from old drive to new drive

Simple enough and it should work. In my case it didn't work and that's when my problems began 3 weeks ago. I will now describe what I tried until I finally managed to solve the issue.

Method 1 - Apple's method

I first tried Apple's method as they explain in the KB article referred above. I started copying ok but it stopped after 36 hours claiming that I did not have permission to access some of the items. This was strange as I am a Admin in my system and have been creating the backups since the beginning. I have another user with standard type but Apple’s article did not refer any issue with users.

Now this is my first big critic that implied having to try different solutions for this long: the size of the backup and the apparent complexity of the data transferred took very long even though both drives are USB 3.0 and directly connected to the iMac. It took ages and every different try-out I had to wait and see if it worked, with each failure being very frustrating. Apple could create a detection system that after preparing the copy (which already takes forever) could detect if the copy could be made.

So this time I try a new method that I found googling.

Method 2 - Disk Utility

In this page (https://www.boy.sh/knows/to-move-your-time-machine-backup-to-another-disk-use-di sk-utility) the author is very helpfull in describing and comparing different methods for this task. I followed the instructions for the Disk Utility method and it failed again saying in the error message that it could not verify the sizes of the drives. I checked in other sites describing this method and it always failed no matter how hard I tried.

This is when I called Apple, taking advantage of the Apple Care I bought when I got the iMac. 5 days had passed by since I started.

Method 3 - Apple care method

After describing the issues I had to the Apple collaborator I was taken a back with the first serious proposal towards a solution:

- Why do you want to keep the old backups?

- If the computer is running ok now why not start anew with the new drive and forget the old backups?

I was not believing my ears and quickly explained that this exactly the purpose of a time machine backup, to cover the possibilities of recovering a file that was modified or erased in the past, especially a file that I do not know today that I need, and have it just in case I need it.

As I was not convinced with the easiest solution, she proposed that I try again copying the folder with Finder, however selecting "Copy" in the edit menu and "Paste" in the edit menu in the new drive. She explained that although similar to dragging the folder, Finder would treat this differently.

And it did: it failed only after 6 hours (the first 4 hours preparing to copy and 2 hours copying 250 Gb) with the same error that I did not have permission to access some of the items.

This is when I started a little bit in overdrive. I wanted to get this thing done.

I contacted the lady again and she asked me to wait for a day or two as she was trying to obtain a new solution. 9 days had passed since I started.

I also started reading a lot of different posts and solutions proposed, never finding anything explicitly regarding the failure to access.

After a couple of days of searching internet and waiting on Applecare, I got a new contact that basically was trying different approaches to same methods and After trying again it gain failed after 250 Gb.

I then started investigating the permissions issue. I found out that many folders inside the time machine under my user and past users were not accessible (with red forbidden sign). I searched in vain for any solution in changing the permissions of backup folders, and owners, and UIDs, always ending in the impossibility to changed the backups. I also found that the forbidden folders were concentrated in the last 6 months of 4 years backup.

I started deleting folders in Time Machine using TM interface. I deleted all backups of the other standard user and erased some of the folders with red sign. I recommend using tmutil command in terminal for erasing multiple date folders.

I ended up erasing many folders and keeping only one folder per month for the last 2,5 years or so. Tried again copying with Copy and Paste and it failed again. More than 2 weeks had passed by.

I then stumbled on Super Duper (https://www.shirt-pocket.com/SuperDuper/SuperDuperDescription.html)

Method 4 - Super Duper

I was reading about cloning the drive to the new drive block by block, and in the past I had used Carbon Copy Cloner. I now read that CCC is paid and does not explicitly clone TM Backups. I keep reading and someone refers Super Duper.

I gave it a try after not finding any reference for not being able to clone a TM Backup drive and after 56 hours (!!) it cloned the Old drive in the New drive! this is such a relief. 3 weeks have passed and such a simple task became an ingrate obsession and destined to failure if not had found SUPER DUPER.

Thus, in conclusion, I definitely recommend starting directly with this method before all else as it avoids the time spent waiting for the others to fail. Also, in the end I regret having erased older backups as this did not contributed to the solution, only made it quicker to copy.

Hope this helps anyone out there.

Cheers

JP

System used:

Mac (27-inch, Late 2013)

3,2 GHz Intel Core i5

macOS High Sierra 10.13.3