Users may find that a second internal or external hard drive suddenly no longer mounts. Upon running a verification/repair in Disk Utility, said users will receive output that states "Invalid content in Journal". Repairing the disk with Disk Utility is unsuccessful, even though Disk Utility claims otherwise.
As described by Apple Discussions poster mtu: "Repairing shows success, but it's not really successful because if I run the verify a second time, the error appears again and the disk is still unmountable."
The journal on the drive (provided it is enabled) is a place where the system stores information before altering the contents of the drive. This lowers the probability of data corruption if the system suddenly loses power or communication with the drive during a write or delete of drive contents. Corruption in the journal could lead to the aforementioned problems if the computer is attempting to read the journal to repair or check the drive before mounting it.
Fix First, with the problematic drive connected, run the following command in the terminal:
- diskutil list
- /System/Library/Filesystems/hfs.fs/hfs.util -N /dev/IDENTIFIER
NOTE: The "IDENTIFIER" should be something like "disk0s3"
After these commands have been run, try mounting the drive again with Disk Utility. You should be able to re-enable journaling on the volume after it mounts, either by using disk utility or by running the following command:
- /System/Library/Filesystems/hfs.fs/hfs.util -J /Volumes/VOLUME_NAME
NOTE: The "VOLUME_NAME" is the disk's name as it appears in the Finder.