- May 4, 2017
Sorry for the necro-bump. Just wondering where I can look for how to do a proper cloned bootable (if possible) backup in Catalina, Big Sur, and Monterey? If I have clients that want to back up their work and are using Apple Silicon or a T2 device and DONT want to use commercial software like CCC or SuperDuper, what is the best way to advise them?I FOUND THE SOLUTION to using Apple Disk Utility to create RELIABLE disk images of APFS drives. It was not easy to figure out. The ONLY path to make a viable re-usable disk image formatted as APFS is:
1. First create a blank image file formatted as APFS and Read/Write (requires pre-determining size of image file).
IMPORTANT NOTE: The image (destination) cannot be stored on the same drive or partition (source) from which you are going to create the image.
2. use Restore from <volume> to clone to newly created image file
(Highlight destination <volume> then click [Restore] button and select Restore From <volume>.
3. convert image file to Compressed format (Image > Convert).
ONLY THEN do you have a reliable APFS image, especially w/bootable macOS. I have done this repeatedly and it works fine.
ANY other options/paths, are greyed out, yield "Resource busy" or "image is not APFS format" errors or produces image that is not reliable. Even using Apple Internet Recovery tools/boot was the same.
NOTE: you do NOT need to do ANY of this using Recovery tools. You can do this from a live boot of macOS drive. If you do not have a destination to store the image file other than the same internal drive, you can create a partition large enough to store the image file, using Disk Utility. And yes, you can partition macOS boot drive live.
CAVEAT: Tested only using Mojave 10.14.4 on 2019 27" i9 iMac w 40GB RAM and 512GB SSD (no T2 chip), so YMMV.
Apple needs to fix Disk Utility to work straightforward like it used to but with better support for APFS.