Introduction

Physical Block size is the smallest amount of data that can be written at one time to a disk. Recent versions of Macs use 4096 bytes block size (4k sector size), while the default sector size on earlier Macs is 512 bytes.

When the backup is being recovered to a Mac with a different block size, it is impossible to automatically remap partitions. As the result, the restored system may be unbootable.

The macOS device block size can be determined by executing the following command from a Terminal window prompt:

diskutil info / | grep "Block Size"

Solution

If you want to recover your Entire Mac backup or disk backup to a Mac with a different sector size, follow the steps below:

1. Recover data from the backup to an external hard drive

   (!) There is no need to recover the EFI partition, it can be skipped at this step.

2. Connect the disk with the recovered system to the destination Mac.
3. Enter Mac in Recovery Mode:
   • Shut down the Mac. 
   • Power On the Mac, and press and hold the Command + R keys.
   • When you see Spinning Globe, Apple logo, or startup screen, release the Command + R keys. Now you should see the macOS Recovery Screen options.
4. Select Disk Utility. In the toolbar, click Show All Devices.
5. Select the destination Mac's internal disk and click Erase in the toolbar. Select the APFS format and confirm erasing.
6. Select Reinstall macOS and follow the steps to install macOS on the internal disk.
7. When macOS boots for the first time, configure the system settings.
8. In the Migration Assistant window, select to transfer data From a Mac, Time Machine backup or Startup disk.
9. In the Transfer information to this Mac window, select the disk with the recovered partitions.
10. In the Select the information to transfer window, select all the information displayed and create a password.
11. After the procedure is complete, install Acronis True Image on the recovered Mac.