"Space Verification failed" / "Underallocation Detected on Main device"

I have a 2017 MacBook Pro 13" that was set up as new (not restored from time machine etc), and which I upgraded to High Sierra 10.13.


From the time of the upgrade, when I run first aid on the internal SSD (512gb), Disk Utility (whether run from normal system or from the recovery partition) has reported something similar to the following:


Verifying allocated space.

error: Underallocation Detected on Main device: (45400420+1) bitmap address (31909)

Space Verification failed.

The volume /dev/rdisk1s1 could not be verified completely.

File system check exit code is 0.

Restoring the original state found as mounted.


This was not fixed on upgrading to 10.13.1; I get the same result, again regardless of whether it is run from the normal system or from the recovery partition.


The full log from the check I have just performed from the recovery partition is below. I've seen a few reports of the same problem on the web, but no solution. DiskWarrior and Drive Genius do not yet support APFS.


Thanks


---


Repairing file system.

Volume was successfully unmounted.

Performing fsck_apfs -y -x /dev/rdisk2s1

Checking volume.

Checking the container superblock.

Checking the EFI jumpstart record.

Checking the space manager.

Checking the object map.

Checking the APFS volume superblock.

Checking the object map.

Checking the fsroot tree.

Checking the snapshot metadata tree.

Checking the extent ref tree.

Checking the snapshots.

Checking snapshot 1 of 5.

Checking snapshot 2 of 5.

Checking snapshot 3 of 5.

Checking snapshot 4 of 5.

Checking snapshot 5 of 5.

Verifying allocated space.

error: Underallocation Detected on Main device: (45400420+1) bitmap address (31909)

Space Verification failed.

The volume /dev/rdisk2s1 could not be verified completely.

File system check exit code is 0.

Restoring the original state found as mounted.

Operation successful.

Replies

From the time of the upgrade, when I run first aid on the internal SSD (512gb), Disk Utility (whether run from normal system or from the recovery partition) has reported something similar to the following

You might have better luck asking this question over in Apple Support Communities, run by AppleCare.

Share and Enjoy

Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"