After crash and unexpected reboot of Oracle VirtualBox app on MacOS Monterey beta, Disk Utility on Macintosh HD shows a huge list of "warning - orphan omap mappings found for old xxxxxxx" or "for old range xxxxx-xxxxx".
Disk Utility says "performing deferred repairs" and "exit code 0. volume appears to be OK", but errors persist on rescan. Does this need to be fixed, and how? Thanks. (reported on Feedback Assistant also).
I advise you to run Disk Utility in recovery mode. Thus there will be one uniq process running on your disk.
It is safer and faster.
Exactly the same messages on the internal drive of a late-2016 MacBook Pro, running Disk First Aid on the APFS volume group from the recovery 'macos Base System' APFS system volume with Cmd-R at startup.
An external bootable installer 'Install macOS Monterey' created following HT201372 will not boot, but drop into the 'macos Base System' APFS system volume disk image and may not be able to repair the drive it's stored on.
The external installer is selectable after option-startup, but not available as startup disk in the Startup Disk tool. Converting the USB Mac OS Extended drive to APFS takes it out of the option-startup menu.