The Practice of Code

Ever had a disk that wouldn’t mount under OS X? In my case, it checked out under Disk Utility and fsck just fine. A look in Console revealed errors like:

Jun 24 11:38:31 computer kernel[0]: jnl: disk2s3: open: journal magic is bad (0x0 != 0x4a4e4c78)
Jun 24 11:38:31 computer kernel[0]: hfs: late jnl init: failed to open/create the journal (retval 0).

We were able to resolve it by disabling the journal. We had to use the diskutil command line tool to accomplish this, and we had to add the force parameter. Use diskutil list to identify the device ID of your volume. In my case, it was disk2s3. So the command to forcibly remove the journal was:

diskutil disableJournal force /dev/disk2s3