Home Forums Peripherals & Multimedia Peripherals Recover files from corrupted external HD?

Last week my external drive bit the dust. To make sure what had failed, I pulled the HD out of the enclosure, and installed another drive that I know to be good. It wasn't recognized either. So, I assumed that the logic board in the drive enclosure had failed and that the drive itself may still be good. So I picked up another enclosure today. Now, my Mac recognizes that I've got a drive attached, but it gives me this message:
"The disk you inserted was not readable by this computer."
and gives me the options to: Initialize, eject or ignore.

From this I'm assuming that when the logic board failed, it managed to corrupt something on the drive. Disk Utility won't give me the option to mount it. So, I can't run the verify/repair functions.

I'm hoping that the majority of the files are still okay, but don't know what software I would need to recover them. Can anyone give some suggestions.

Data Rescue is a good place to start.

Thanks. I just downloaded the free version. It's busy doing a scan now.

Here's an interesting point. It's a 1000GB drive with only one partition. Both Disk Utility and Data Rescue show the single partition to be 250GB. I guess this could be because of the data corruption, but I wonder if that means that it will only scan 250GB instead of the entire drive.

Update:
It finished its scan, and appears to have found all of my files. So, I bought the lite version (250GB) which should be enough to get back everything I lost.

Thanks again.

Some USB drive enclosures, especially cheap ones, have limitations on the size of the drive they can access--put a 1 TB hard drive in the enclosure and it will "read" as 250 GB or 500 GB to an attached computer.

Interesting. I would have thought that by now, almost anything should work with a 1TB drive.

Anyway, the recovery went well. I got back all of the important files.

However, I had also been using this drive as my Time Machine backup. So all of the Time Machine backup files are still on the drive. At this point I'm trying to decide whether I want to recover all of the backups. If I do, then it will probably put me over the Data Rescue license limit of 250GB. At first, I was thinking that I could just restore the backups from one week then skip a couple of weeks, etc., but since these are all incremental backups, I assume that that wouldn't work and that this is an all or nothing affair.

The Time Machine backups represent the state of your system as of a given date and time. You can restore the state of the entire system as of a given date and time in history or you can select individual files as of that date and time. In your case you have two options

1. Delete the entire Time Machine backup data set and start over from the current state, in which case you lose all of the "history" of past versions.
2. Recover the entire Time Machine backup data set and hope that in the process all of the critical multi-links will be recovered correctly — which is unlikely.

Unless you have a strong reason to believe you will need to go back to a previous version of the entire system or will need to recover previous versions of some data file(s), I recommend option 1.

By-the-way, Apple does not recommend putting the Time Machine backups on a drive with any other files. Not even if you put the Time Machine data set in a separate partition.

By now, almost everything SHOULD work with a 1 TB drive. But there are still plenty of old chips sitting on warehouse shelves. Often, they get sold in bulk for pennies on the dollar to Chinese companies that use them to make cheap enclosures that don't work with modern drives.

If you ever use the Geek app, you'll find Pebble watches for $35 and 64 GB thumb drives for $7. How do they sell them so cheaply? They're made from parts that didn't pass quality control, or cheap components that didn't meet the original manufacturer's specs.

I bit the bullet and reformatted the drive. I've only been using this drive for TM backups for less than a year anyway. So, I can't see that there's likely to be anything I would ever need to recover. I tend to manually back up my really important files to other media anyway.

As recommended, I'll keep this drive strictly for TM backups from now on.

Here's an interesting side note. I've been lucky in that I've never had a physical failure on any hard drive that I've owned, but I have had failures in the enclosure electronics a few times.

counting only those at home, not at work, my rough estimate:
- 8 enclosure bridge boards
- 5 enclosure adapters
- 14 drives

So I keep bridge boards/enclosure cases as well as power adapters. I often can reuse one to fix another. Power adapter failures are surprisingly common and of course are very easy to fix.