External hard drive deep freezing Macs A quite nice problem:
I have an external USB 2.0 harddrive (Lacie Starck with 512GB) which was working fine during the last years. But now everytime I connect it to a Mac 3 seconds later a total crash of the system follows and the Mac needs to reboot.

I tried with OS 10.10, 10.9 and 10.6 on three different devices. All systems crashed, so it's not my Mac.

I removed the harddrive from it's case and put it into a new external case. Still crashing, so it's not the controller.

If I start the Mac into Recovery Mode and plug in the external harddrive there is again an immediate crash.

The disk itself still produces a good spinning sound but it's a killer-disk now... Problem is: I don't have any other PC with Linux or Windows and I want to get some files from the disk. Any suggestions?
I had this same issue, when I backup a Laptop from OSX to my External HD.  Months later, I was taking the backup HD, and cloning it's content to a Sparse file via SuperDuper.  However, randomly the process would die and the HD would act like it locked up.

For me the solution was to stop Spotlight from Scanning the HD.  This allowed me to utilize SuperDuper again, to take the image from the HD, move it to a Sparse image, which I could then backup on a NAS or offside disaster recovery, freeing the HD for other jobs.  I included the steps from an [article that helped me] to avoid future dead links.

Exclude Specific Items from Spotlight Indexing


  This is by far the simplest way to universally exclude something from
  Spotlight searches and it works in all versions of Mac OS X



System Preferences from the  Apple menu and choose the “Spotlight” preference panel
Click on the “Privacy” tab
Drag &amp; drop folders or drives to exclude from the Spotlight index, or click the “+” plus icon in the corner to manually select hard drives or directories


Result:


  Spotlight will now NOT scan your HD, thus it won't hit that corrupted
  file or OSX unfriendly file.