Rescue Corrupted WD External HDD

Yes -- but if the *OS* expects the drive to accept them (e.g., because the OS has no concept of a write-protected drive of this type), then, at the very least, you end up with the drive's state not coinciding with the OS's notion of the drive's state!

I recall something like that in a FAQ for clonezilla:

Q. I have mixed up my source and destination disk when cloning. What should I do? A. Cry.

Windows is not a very good operating system for disc recovery. I once discovered this the hard way. I had been imaging a badly corrupted disc on a Windows machine using dd-rescue (for a couple of weeks as there were many bad blocks) and there was a power failure. After rebooting, Windows was now able to see the copy that I had been making and automatically started to "recover" the filesystem which is not what I wanted at that time as it meant that any further attempts at recovering the bad blocks would put them in the wrong place and totally mess things up.

I have tried many commercial recovery programs and concluded that for raw copying of badly corrupted drives gnu dd_rescue is by far the most reliable tool, so long as it is used under Linux and not Windows.

Once there are a few clones in hand, then there is plenty of scope to experiment and find which tool does the best job at recovering the filesystem and data.

It is not essential to have a separate disc of greater capacity than the original for each clone, although this can be convenient. dd_rescue can be made to compress the target drive on the fly and store the results in an image file which may be much smaller than the original filesystem. This can then be re-expanded back to a target drive each time a data recovery strategy is being tried out. Read the instructions several times before you start and don't hurry.

John

with the case unopened you your warranty is still valid.

If the drive has an external powersupply (but I think it's mainly 3.5" drives that do) that could have gone bad, you could try substituting another.

The drive presumably is EXT2 or EXT3 formatted, by a Linux system? There are repair tools in Linux to repair a filesystem, which is probably what you want. Windows will be an impediment, unless you find something NTFS-like on close examination.

Firstly, there's hardware: presumably, all the WD parts are functional. The suggestion was made to remove the drive from the external case and connect to a SATA port: this will speed all disk operations, but violate your WD warranty. Not recommended.

Secondly, there's a partition scheme on the disk (it could have EXT3 and other file systems on different partitions). It could be the partition structure that is corrupt (the partition map).

Thirdly, one or more partitions could be corrupt enough to not mount automatically; this is filesystem repair (an EXT3 partition contains a filesystem). This is highly likely. Windows tries to repair on startup (but that's no use on an EXT3 disk), but maybe your Linux flavor doesn't.

So the basic scheme is to first test hardware. Identify any visible partitions, (if you see partitions, the disk IS responsive and presumably hardware OK). Figure which partitions are the file containing ones, and (typically without mounting the partitions) aim various repair programs (fsck and offspring...) at those partitions. When you can mount the partition, your files are recovered.

There's some guides online: this one looks interesting.

if its windows 7 or 8 then you have to first give the drive a letter before it will come up. There is a system tool for this, but I forget which one...

It's an *external* drive.

Disk drives are so cheap, anymore, that the warranty doesn't matter. I'd prefer they didn't get the drive back, with my data on it either.

Also happens with proprietary file systems used on e.g. Topfield PVRs. If the bare drive is connected to a Windows machine, for data recovery purposes, you have to be very wary that it doesn't take one look at trash it further!