Hard drive unmounted and missing then back? I have a 15" 2011 MBP with the OWC data doubler (a generic version).  In my primary drive position (the spot where the factory HDD was) I have an OCZ-VERTEX 3.  In the data doubler (the spot where the factory DVD drive was) I have the factory HDD (500 GB Hitachi).

The other day, I opened my MBP resuming from sleep and the OS told me a drive had been unmounted unexpectedly (or something like that).  The first thing I did was open finder and I saw that the factory drive's mount was missing.  I checked in the System Profiler under Serial-ATA and the drive didn't show up.

I rebooted a couple times and it the mount point never came back.  I was traveling at the time, so I guessed the SATA connector came off and that I'd have to open the case when I got home.  I got home, booted up and the drive was back, the mount point was there and so was all of my data.

As far as I can tell, the Mac doesn't know there was ever a problem.  I've done a little poking around in the logs and I can't find anything indicating what happened.  The drive's smart status says verified...

These are the only possibly relevant log entries I've found:

7/5/11 1:07:27 AM   fseventsd[49]   event logs in /Volumes/Storage/.fseventsd out of sync with volume.  destroying old logs. (375382 2 375384)

7/5/11 1:07:27 AM   fseventsd[49]   log dir: /Volumes/Storage/.fseventsd getting new uuid: A4E5301E-C2AE-482A-B3AE-7553D58CCFFA


I found the device is 'disk0s2' and found these log entries for that:

7/4/11 9:54:47 PM   kernel  BSD root: disk0s2, major 14, minor 2

7/5/11 1:07:26 AM   kernel  jnl: disk0s2: replay_journal: from: 13338112 to: 14224384 (joffset 0xe8e000)

7/5/11 1:07:26 AM   kernel  jnl: disk0s2: journal replay done.


Perhaps it was just a glitch I shouldn't really worry about, but I'd like to know as much as possible about what happened.

What sort of post-mortem diagnostics should I be doing to find out what happened?
I think the safest way to fix it is to copy your data off the drive to save it to somewhere like another external hard drive and then format it!