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Best practice to clean and fix system drive - Monterey 12.7.6

Hi all. OS 12.7.6, late-2015 iMac 27", 48 gig RAM.


So, I'm a new (and unwitting) user of Monterey, and it appears that Apple has decided that my old manner of backing up and keeping my system drive maintained is not OK.


Briefly, I've successfully maintained all my Macs by cloning the hard drive regularly (using commercially available backup software like "SuperDuper"), and if they start acting up, starting from the clone, fixing or erasing the system drive, and then reinstalling the OS and copying data back to the revived system drive.


Apparently, with the advent of Monterey, that's not viable. My SuperDuper "clone" will not boot (and they report issues about this on their site); and downloading "ChronoSync", another backup utility, yields a release note that states that "bootable clones are of less importance in Monterey and beyond". And similar results when creating a "bootable clone".


So, after numerous failed attempts with the 3rd-party solutions, I decided to do it Apple's way.


I turned on Time Machine, and made a complete backup of my system drive. I read all about installing a fresh copy of Monterey "over" the existing data. And proceeded to have no success:


-1) when restarting in Recovery, and attempting to install Monterey onto the system drive, I get this message: "The operation couldn't be completed (com.apple.BuildInfo.preflight.error error 21.)"


-2) when attempting to restore from the Time Machine backup, I get an error that states that I can't, and I need to install Monterey on the system drive first.


So I'm in a Catch-22...cant install the fresh OS, can't use the backup until I install a fresh OS.


What's a person to do?

Posted on Dec 18, 2024 11:36 AM

Reply
2 replies

Dec 18, 2024 6:42 PM in response to Mike Janowski

My first guess is always to check the health of the internal hard drive. You can use DriveDx (free trial period) to check the health of the hard drive. Post the complete DriveDx text report here using the "Additional Text" icon which looks like a piece of paper.


If the drive is healthy, then I would check the file system by running Disk Utility First Aid on the hidden Container (or Fusion Drive item if your system uses a Fusion Drive). Within Disk Utility you may need to click "View" and select "Show All Devices" before the hidden Container or Fusion Drive appears on the left pane of Disk Utility. Even if the First Aid summary says everything is "Ok", click "Show Details" and scroll back through the report to see if any unfixed errors are listed. If there are errors, then run First Aid again until they are gone. If after several attempts the errors remain, then you will need to run First Aid from Recovery Mode.


Another possibility is an issue with some third party software. Run the third party app EtreCheck and post the complete report here so we can examine it for possible clues.....assuming you can boot into macOS.


As for cloning the macOS boot drive, it is still possible to do so using SuperDuper and Carbon Copy Cloner (CCC) at least on Intel Macs (forget about bootable clones on M-series Macs). I don't use Super Duper, but with CCC it requires enabling a "legacy" boot option on the destination in order to make it clone the macOS system volume. Both SD & CCC utilize a macOS command line utility "asr" to actually clone the read-only signed & sealed system volume as that is the only way to keep it signed & sealed.


Reinstalling macOS over top of itself usually doesn't do much on Intel Macs when using macOS 11.x+ because the system volume is now a read-only signed & sealed volume. Sometimes reinstalling macOS over top of itself will make a difference on an M-series Mac because it makes changes to other areas outside of the read-only system volume.


If you are going to perform a clean install by erasing the drive, then make sure to either erase the Fusion Drive item if you system has a Fusion Drive, otherwise erase the whole physical internal drive as GUID partition and APFS (top option). After reinstalling macOS you should be able to restore from your TM backup.




Best practice to clean and fix system drive - Monterey 12.7.6

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