I was computing away on the train this morning, when suddenly I couldn’t use Evernote any more because of an invalid security certificate. This was not what it seemed, and sure enough Safari started showing a bunch of blank security certificates. I closed down the computer and restarted. And received a kernel panic about 10 seconds into the boot before it restarted continually.
tl;dr - Problem solved!
Thankfully that I had backed up on Time Machine the night before, I booted off the backup drive and went into the Disk Utility. I couldn’t repair the SSD because I couldn’t unmount it. The Unmount button didn’t work. The computer wouldn’t boot into safe mode.
I rebooted from a Recovery DVD (although I could have done it the boot from the Time Machine too)
What unmounted it was selecting the disk in Disk Utility and selecting Info to get the name of the disk - for me it was disk0s2.
Closed Disk Utility and select Utilities » Terminal
cd / cd dev umount -fv disk0s2 I could now run Repair Disk and Repair Permissions in Disk Utility.
I had no problems with the Repair Disk (phew!) but there were permissions that were unable to be repaired by Disk Utility and the computer still kernel panicked when I booted.
Rebooted with Time Machine to the Terminal, unmounted the hard disk as above, and tried to restore from Time Machine Backup.
The system failed to see the hard disk.
Erased the partition, and it gave me a formatter error.
Tried to restore again from the Time Machine for the hell of it.
It couldn’t erase the disk.
I took out the SSD, and loaded it in a USB slot with a cable, then booted from the Recovery DVD and erased and reformatted the SSD. Success.
(6 hours later)
It then restored successfully from the Time Machine backup.
Moral of the story? Have recent backups and a Recovery DVD around (but I think the SSD or its cable might be on its way out :)
update: problem recurred. Will try a new Sata cable as suggested in numerous places on the internet.
(several days later)
update: new cable did the trick.
The clue that it wasn’t the SSD drive was that it didn’t have any errors on it when I ran Repair Disk in the Disk Utility. Phew!