Restore Disk Image File To Internal Drive Using Disk Utility

MacUserQandA wrote:

The method I described at the beginning of my post also works for Apple Silicon. I want to restore using a disk image file.

I said in theory it should work, but in practice it usually does not work. Which is why two of us have suggested the well respected third party app CCC. Even years ago long before Apple signed & sealed the system volume, using Disk Utility for such a task did not work properly. With M-series Macs, things are a lot different than with the Intel Macs, even when using the image to boot the exact same computer. M-series Macs also have a new concept of "Ownership" which can cause problems with imaging an M-series boot drive which can cause problems with imaging a boot drive even when the image is used with the exact same computer.

Take it from people who have years of experience supporting Macs and who have made bootable clones for years.

FYI, here is a post from the developer of CCC regarding bootable clones and their advice going forward:

https://bombich.com/en/kb/ccc/6/cloning-macos-system-volumes-apple-software-restore

If a developer with decades of experience with macOS bootable clones is having trouble making it work, then what chance does an average user have? It should be a severe red flag that a bootable clone is not the best option these days and you should look to modify your setup accordingly. Note: Over the years I have never had any issues making bootable clones with CCC although I have never tried it with M-series Macs (I've heard of mixed results with M-series Macs).

MacUserQandA wrote:

I thought putting the disk image on the internal drive was OK until Apple added signed system volume. You can't run open in recovery disk terminal and opening the disk image in disk utility breaks the seal. Still looking for a solution using the tools built into the system.

Technically yes, that should be the case. However, I always encountered problems using Disk Utility to make a bootable clone of macOS. This goes back years. The only option for cloning the system volume is by using the command line "asr" utility which is what Carbon Copy Cloner & SuperDuper must use, however, there may be more to it than just cloning that system volume.

For an Intel Mac it is so much easier to use one of those two third party apps. They've been around for decades and are well respected.

For an M-series Mac, just forget about making bootable clones. You are going to run into even more issues. A clean install & migrating your apps & home folders are the way to do it now for M-series Macs.

MacUserQandA wrote:

Currently on Ventura 13.3.1, but hoping to come up with a solution that will work with the newer operating systems as well. Using Disk Utility, able to copy an installed partition from an external disk drive to the internal drive and then install Ventura over the top to seal it.  This action is performed in recovery disk (utilities).  I want to do the same with a disk image file.

Using Disk Utility, it is possible to create a disk image file without a broken seal (select container in left pane of Disk Utility).  Source disk image is installed on external disk drive (seal unbroken), shrank partition to minimal size. Selected menu item File -> New Image -> Image From “Container <>”.  I will discuss the read only and read write options since I don’t want disk compressed and DVD/CD master is a different file format.

So you want to create a macOS disk image that can be restored as bootable, right?

Carbon Copy Cloner can clone macOS to such "bootable" .dmg and then clone that .dmg to a real bootable macOS to an APFS volume.

I guess it is still possible to do that DIY via Disk Utility or via CLI tools but that is not for the faint of heart.

CCC author has done that but even he seems to be frustrated by the lack of official documentation and restrictions to do this.

Disk Utility has never been good at creating and/or restoring bootable images even years ago before the system files became located on signed & sealed read-only volumes.

@Matti has the solution with CCC assuming you are dealing with an Intel Mac. If it is for an M-series Mac, then forget it. Even the developer of CCC tells people to install macOS to the secondary drive & use CCC to move the data across.

MacUserQandA wrote:

I did find the answer to my own question. Recovery disk or Options on Apple Silicon does have a terminal command to mount a disk image file that does not break the Sealed System Volume (SSV). Obviously, Apple has a big mess here because their documentation in this area no longer works with the SSV.

You are attempting things that are far beyond any documentation.

Disk Utility is a tool for end users. It simply isn't going to do what you are attempting. You might be able to do it using command line tools like asr and similar.

MacUserQandA wrote:

What doesn’t make sense is why the source disk image of restore operation, which should be just reading the source, requires the timestamp to change (implies modification).

I know from using Disk Utility Restore to take an Apple DMG AHT diagnostic image and transfer it to USB would require having Disk Utility scan the image. Sometimes those scans had to be first manually initiated. I never paid attention to whether Disk Utility actually modified the file. From what I've seen of Apple software since that time over a decade ago, it would not surprise me.

FYI, don't try to make sense of what Apple does....you will just drive yourself crazy, or it will just scare you when you realize some of what Apple is actually doing. Like I said before, you are using the wrong tool and possibly even the wrong workflow design if this is for an M-series Mac. It is easy to dig a hole & keep on digging until you are in so deep that you don't see a way out anymore. Stop digging & get out now while you still can. Besides if it is this difficult now, what happens with the next OS update which could break things even more. I understand curiosity, but you are trying to solve the wrong problem here.