Hard Drive Purgatory

September 2, 2008 1:16 AM

The Last-External-Hard-Drive-I-Ever-Buy is stuck between heaven and hell. Can anyone please help me figure out how to rescue it?

I have a USB 2.0 WD Mybook 500gb external HD (essential edition) that is causing me a great deal of grief that none of the earlier posts that came up on my search seem to address, both on askme and other support sites, so this is my last resort before emptying my savings on data recovery...

Up until last week, the drive has been connected via a d-link USB port which was externally powered. We had a power failure in my office causing the disk to be 'unproperly' ejected.

Since then, the drive mounts fine as mybook, but as soon as you try to do anything with it, all programs hang until you manually unplug it (and I have it straight into the usb now). And when I say all programs, I mean, Diskwarrior, Techtool, Onyx, Disk Utility, everything. Nothing can touch it.

Even terminal crashes when I try to run a diskutil list, stopping here:

/dev/disk2
#: TYPE NAME SIZE IDENTIFIER
0: Apple_partition_scheme *465.8 Gi disk2

I've tried repairing in terminal which gives me this:

Error encountered attempting to verify/repair disk2: Unrecognized filesystem (-9958)

As well as resetting PRAM, booting off the original CD's and trying things that way. Nothing seems to do the trick. Even Data Rescue II which I ran overnight just froze at the prescan stage the whole time.

All the steps above came out of my initial research, so I still consider myself an advanced novice in these matters, so if anyone in the hive can perhaps suggest some sort of Jedi move I can pull on this, or failing that, a recommendation for Data Recovery in the Melbourne area who can do some sort of evaluation, I would be most grateful.

Thanksyou!

posted by LongDrive to computers & internet (5 comments total)

I don't know how the MyBook is snapped together, but you might be able to try removing the actual hard drive from the external USB enclosure and popping that into a computer. Note that you may wind up destroying the enclosure to get at the hard drive, depending on glue, etc.

The actual hard drive is typically a IDE drive or possibly SATA. If it's IDE, it might be a notebook 2.5" form factor. It should work fine inside your desktop, though possibly with some sort of cable adapter.

If you can put it into a desktop, you can at least see if it's the enclosure's circuitry that got fried. It'll take one element out of the possible chain of problems.
posted by chengjih at 3:02 AM on September 2, 2008

I guess the best bet would be to pull the drive from the enclosure and find a desktop machine to install it into.

Unfortunately, My Book external drives seem to have a higher-than-normal failure rate when used with Macs, but it's just a normal desktop drive inside with a normal failure rate, so if you take it out you'll be removing whatever variables are introduced by the enclosure.

As far as I can tell from reading the Apple Discussions threads on the subject (this is now about a year ago, when I was considering getting one), the issues seem to be related to the USB/FW bridge used by the enclosure and the fact that someone (WD says it's Apple, Apple has nothing to say about it, I guess because it's kind of ridiculous) didn't quite design their connectors in accordance with standards.

Another thing that is slightly possible is that the freezes are due to trying to get more voltage over USB than is available for whatever reason (although usually on OS X this would fail gracefully with a warning) so you could also try re-attaching the drive to the powered USB hub and disconnecting all other usb devices just to rule that out. Good luck!
posted by Your Time Machine Sucks at 3:04 AM on September 2, 2008

Heh, shoulda previewed.
posted by Your Time Machine Sucks at 3:05 AM on September 2, 2008

Great suggestions! I tried ddrepair (which didn't work) before taking the assembly apart and am going to but it into my spare beige box tomorrow and report back :)
posted by LongDrive at 4:37 AM on September 2, 2008

The following is generic UNIX advice. I expect it holds true for Mac OS X as well, but my only Mac is packed away at the moment so I have no good way to test it. I have had filesystem corruption on the Mac a couple of times and DiskWarrior solved them both.

My first step when trying to work through a disk issue is to make sure I have an up-to-date copy of everything before I start. I follow a strict backup regimen already (losing a few disks will ingrain that in you or at least it did in my case), but I always use the UNIX dd command to make an image of the disk and/or partitions and copy it to another system before I do anything else.

Once you have the image, you can copy it to another system and try anything you like without fear since it's just a copy. If you're able to mount it on another system, your recovery could be as easy as simply copying data from the mounted filesystem to another disk (preferably using tar and gzip), then repartitioning/reformatting the original disk and copying the data back over.
posted by tomwheeler at 6:59 AM on September 2, 2008