Disk Utility still can't check and repair APFS volumes and containers (2021)
Checking and repairing disks is one of the more important tasks performed by Disk Utility, but ever since the introduction of APFS, it has been more fraught than it should have been. One of its most persistent and pervasive problems has been complete failure because Disk Utility has been unable to unmount volumes or containers. To my shock, in Monterey 12.0.1 this problem appears worse than ever, and I now have one disk which Disk Utility is completely unable to check or repair. This article sug