You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

APFS format fails

When I try to format my external Crucial P5 2TB M.2 NVMe PCLe SSD on my M1 MacBook Air using disk utility on OS Monterey I keep getting the following....


Erasing “ASMT USB 3.2 Device Media” (disk4) and creating “Untitled”


Unmounting disk

Creating the partition map

Waiting for partitions to activate

Formatting disk4s2 as Mac OS Extended (Journaled) with name Untitled

Initialized /dev/rdisk4s2 as a 2 TB case-insensitive HFS Plus volume with a 155648k journal


Mounting disk

Creating a new empty APFS Container

Unmounting Volumes

Switching disk4s2 to APFS

Couldn’t read partition map. : (-69876)


Operation failed…

Does anyone have any idea what I'm doing wrong?


MacBook Air 13″, macOS 12.5

Posted on Aug 9, 2022 10:21 AM

Reply
Question marked as Top-ranking reply

Posted on Aug 9, 2022 10:37 AM

A few non-specific things to try.


  • If you have any anti-virus or cleanup apps installed, uninstall them according to the developer’s instructions.
  • If you are connecting the SSD via a hub, try again with the SSD plugged directly into your MBA
  • Try again in Safe Mode
  • Try a different USB cable
  • Quit any running apps before trying again

Similar questions

6 replies
Question marked as Top-ranking reply

Aug 9, 2022 10:37 AM in response to ducatijim

A few non-specific things to try.


  • If you have any anti-virus or cleanup apps installed, uninstall them according to the developer’s instructions.
  • If you are connecting the SSD via a hub, try again with the SSD plugged directly into your MBA
  • Try again in Safe Mode
  • Try a different USB cable
  • Quit any running apps before trying again

APFS format fails

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.