My hard disk has decided to not mount anymore. It has a partition, one I use for Time Machine and the other I use for storing files. This is what diskutil list looks like. Is my work all gone?

vinayakmenon@Vinayaks-Air ~ % diskutil list        
/dev/disk0 (internal):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                         251.0 GB   disk0
   1:             Apple_APFS_ISC ⁨⁩                        524.3 MB   disk0s1
   2:                 Apple_APFS ⁨Container disk3⁩         245.1 GB   disk0s2
   3:        Apple_APFS_Recovery ⁨⁩                        5.4 GB     disk0s3

/dev/disk3 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +245.1 GB   disk3
                                 Physical Store disk0s2
   1:                APFS Volume ⁨Macintosh HD⁩            15.2 GB    disk3s1
   2:              APFS Snapshot ⁨com.apple.os.update-...⁩ 15.2 GB    disk3s1s1
   3:                APFS Volume ⁨Preboot⁩                 626.0 MB   disk3s2
   4:                APFS Volume ⁨Recovery⁩                798.1 MB   disk3s3
   5:                APFS Volume ⁨Data⁩                    180.6 GB   disk3s5
   6:                APFS Volume ⁨VM⁩                      24.6 KB    disk3s6

/dev/disk4 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *2.0 TB     disk4
   1:                        EFI ⁨EFI⁩                     209.7 MB   disk4s1
   2:                 Apple_APFS ⁨Container disk5⁩         2.0 TB     disk4s2

/dev/disk5 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +ERROR      disk5
                                 Physical Store disk4s2
   1:                APFS Volume ⁨DATA⁩                    ERROR      disk5s1
   2:                APFS Volume ⁨My Passport for Mac⁩     ERROR      disk5s2

disk4 and disk5 is where the problem lies. I am wondering what the solution is. When I am opening files like iBoySoft the files are there and clear to see that my hard disk has not been wiped. However, it will not mount.

1 Answer 1


I've been experiencing this same issue. Kept digging and searching and found the following entries:



Since I was using APFS, I didn't think the sudo pkill -f fsck would do the trick for me. But, the other common solution was to just reboot the Mac. It seems this external drive issue is a common problem with some recent updates for Big Sur and/or Monterey. I tried rebooting and the external drive was auto-mounted successfully! Everything is back in working order! My Time Machine backup is executing as I type...

I knew that rebooting was a common solution for Windows machines. I guess that "feature" is creeping into Macs as well... :-)

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