Storage: the plex is missing

Last year, in the midst of migrating the VM farm from VMware to VirtualBox, I had a Seagate drive go tits up. Luckily it was part of a RAID so I just substituted another drive and that was that. It was still under warranty so I figured that one day I would clear out the confidential data and RMA the thing. No rush.

Every so often, as time permitted, I would haul the thing out and play with it a little. This morning was one of those times.

Since I’ve been rather unsuccessful with the thing so far I figured to try swapping logic boards on the drive. I’ve got a spare, of sorts; it’s on a drive that’s part of the RAID mirror in my primary desktop. Software RAID, that is, on a Windows 7 system.

It’d be a simple matter to pull the drive, failing the RAID. Then the plan was to install the known-good logic board onto the failed drive, cable it up to the ESATA port and (possibly) do the wipe. Recovery would be just as easy. Replace the logic board and re-install the RAID drive. Then recover/resync the mirror and that would be that.

Before I got started I figured a backup would be prudent. The RAID mirror is where I do all my work. The better part of a terabyte was soon copied to a spare drive.

The drive pull took but a moment. Gotta love those big, roomy cases! I booted to find that the array had NOT failed; instead it went missing altogether! Oops. No concern, though, right?Microsoft documentation says that breaking a mirror results in two drives containing the data, just no more mirror. My exercise should have merely simulated a drive failure. When I re-installed the drive it should be fine.

Okay, so I did the logic board swap and futzed with that a bit, still feeling a bit uneasy about the mirror. Didn’t get anywhere for my trouble. It looks like the failed drive is just that – a failed drive. (More about that later.)

I put the known-good logic board back on the mirror drive, shoved it into the case, cabled it up and booted. Uh oh. Still no mirror. One of the two formerly mirrored drives appeared uninitialized while the other was foreign. I imported the foreign disk, which then got its old drive letter back.The data appeared to be intact but (I guess) since the companion volume remained uninitialized it still reported itself as having “failed redundancy.” I couldn’t break the mirror, nor could I remove the mirror. It looked like it was in some kind of limbo. I tried to reactivate the volume and had a nice little “WTF” moment: “the plex is missing” mocked the resulting error message.

I’m running out of time, there’s stuff I need to be doing and it’s certainly not this.

I initialized the uninitialized drive, made it dynamic and formatted it. Then I copied the data from the drive whose plex – whatever the hell that is – was missing onto the newly formatted volume. Continuing, I wiped the plex-less drive. Would it now offer itself up as a candidate to accept a mirror? Yes, it would. So I did just that and it took a while – longer than all the file copying – to resync.

Now, I’ve had good luck with Windows’ software RAID mirrors before but this exercise worried me a little. Should I have broken the mirror instead of simply yanking the drive? What if it had failed electrically? Or if I knocked a cable loose doing some unrelated maintenance? Or someone stole the drive? What happens when a drive fails under certain circumstances? Have I just been lucky all along, where the failures I’ve experienced have just been the right kind of failures that were recoverable? Ponder, ponder.

I guess I need to set up a testbed VM and experiment. Meanwhile, I have my panic copy and the same mirror arrangement I had this morning, no lossage.

Oh, and the old drive that I was trying to wipe? Glad you asked. It’s still on the shelf. There’s confidential data on there, if one were to recover it. I haven’t been able to get to it in order to properly cleanse it. I don’t trust Seagate; not that Seagate’s evil or anything. It’s just that, well, the responsibility’s mine and I don’t take that lightly. Terabyte drives are only worth about $75 retail these days and I got a couple of good years out of the thing.

What would YOU do with a drive full of confidential but unreachable data? Can you suggest any tools that I might use to get at the drive to wipe it without needing to access it with Windows or Linux, the two predominant OSs we run here?

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2 thoughts on “Storage: the plex is missing”

  1. I like your last ditch thoughts, Mister Schnookeroonie. Except I was thinking more along the lines of introducing it to my sixty-year-old drill press. Truth be told, I’ve got a small collection of stuff waiting for that fate. Why not add this?

    But I’m wondering whether one of those boot-from-this-and-wipe-all-attached-drives programs will do it. The drive’s new enough that it has the self-destruction algorithms onboard. If it’s good enough for the government, it’s good enough for… Hmmm, was I really about to say that??

  2. Know anybody with an MRI machine?

    Failing that, I’d find an old CRT monitor or TV and grab the focusing magnet(s), put them on the drive and spin it up (provided those focusing magnets didn’t interfere with the motor running.

    Another option — junkyard crane with an electromagnet.

    Last ditch? For a mere $75 replacement cost, I’d get a Torx driver, take the cover off the drive, run magnets over the surface of the platters (maybe disassembling the platter stack), and smash all the platters with a sledge.

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