"warning: MT mapping (0x40000009c4be3 -> 0x57bdeb, 2, C) is not completely referenced"
When using Disc Utility I get this message which appears several times and I wonder if it is a fault or something I can clear ?
I have a fusion disk running OS12.7.6 and 4 GHz Quad-Core Intel Core i7
iMac 27″, macOS 12.7
Are you having an actual problem with this system?
Have you tried running First Aid from Recovery Mode?
If you have run First Aid from Recovery Mode and these warnings remain after several scans, then they cannot be repaired. You can try the "Erase All Content & Settings", but there is a good chance those warnings will still remain since they are tied to the hidden APFS Container rather than a specific APFS volume.
Since they appear to be from a scan of the APFS Container of the internal boot drive, the most likely the only way to get rid of them is to use Disk utility to erase the "Volume Group" followed by reinstalling macOS & restoring your data from a backup. See the following Apple article for details.....using the "Erase All Content & Settings" option won't help you since the issue affects the Container which also houses the APFS signed & sealed read-only volume containing the macOS system files....that APFS volume also needs to be recreated.
Erase your Mac and reset it to factory settings - Apple Support
People may tell you that these First Aid "warnings" are not a problem, but some of them can be just as much of a problem as actual "errors" (personal experience).
Are you having an actual problem with this system?
Have you tried running First Aid from Recovery Mode?
If you have run First Aid from Recovery Mode and these warnings remain after several scans, then they cannot be repaired. You can try the "Erase All Content & Settings", but there is a good chance those warnings will still remain since they are tied to the hidden APFS Container rather than a specific APFS volume.
Since they appear to be from a scan of the APFS Container of the internal boot drive, the most likely the only way to get rid of them is to use Disk utility to erase the "Volume Group" followed by reinstalling macOS & restoring your data from a backup. See the following Apple article for details.....using the "Erase All Content & Settings" option won't help you since the issue affects the Container which also houses the APFS signed & sealed read-only volume containing the macOS system files....that APFS volume also needs to be recreated.
Erase your Mac and reset it to factory settings - Apple Support
People may tell you that these First Aid "warnings" are not a problem, but some of them can be just as much of a problem as actual "errors" (personal experience).
What version of macOS are you on? This can mean a dysfunctional system
Make sure that your system is backed up, and try disk first aid via disk utility
If this is not working, you might want to reset the SMC and the NVRAM
Reset NVRAM on your Mac - Apple Support
Reset the SMC of your Mac - Apple Support
If the issue persists you might need to reinstall macOS
I've done all these things and reinstalled but Disk Utility always gives the same numbers. See belowFirst aid always says the same
Disk Utility 'warning: MT mapping' on fusion drive?
