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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?

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It's very hard to diagnose a problem that doesn't occur anymore and that left little or no trace, but pay attention to the drive, if it happens again, the SSD may be faulty. SSDs are -contrary to popular belief- very unreliable and although some of us have been very lucky, the drives tend to fail more often than not. It sounds like for some reason, your drive got disconnected while the computer was asleep, perhaps you could check the connection to make sure it's firmly attached to it. – Martín Marconcini Jul 7 '11 at 8:30

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!

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As Martin said, you cannot really find out what happened.

Just back up all of your files, and hope for the best. If something bad happens, replace the SSD and back it back up.

Other than that, there really isn't much you can do. Just take note of it, take precautions, and go on with your day.

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