URGENT: Fastest "Bit for Bit" Backup?

[shorty116]

I have a broken external HD. I tried everything from Disk Utility to DiskWarrior to Techtool Pro to repair it - no success. Then i put it in the freezer (for 1 hour) and it actually worked for some seconds. Now i will leave it in the freezer for 24 hours to at least get some minutes with my data.

As i probably won't have more than a few minutes, what is the fastest way to backup stuff? Normal copy/paste needs like forever because it first needs to determine how much files there are and secondly, as far as i know if it stops copying while not finished yet the whole copy process will be aborted… So i need something that copies "bit for bit" so that i can use every data copied until the HD dies again… any help appreciated!

 

[lannister80]

http://www.macosxhints.com/article.php?story=20050302225659382

"Normally, in order to make a disk image, the disk you're copying from has to be able to spin up and talk -- in other words, it's OK to make a copy if the disk is healthy. But what happens when your disk is becoming a doorstop? As long as it continues to spin, even with physical damage on the drive, dd and Mac OS X will get you out of the fire."

The answer is: dd.

If you can't run dd because of security warnings, you may need to prepend the command string with "sudo" and authenticate yourself.

 

[sushi]

I have a broken external HD. I tried everything from Disk Utility to DiskWarrior to Techtool Pro to repair it - no success. Then i put it in the freezer (for 1 hour) and it actually worked for some seconds. Now i will leave it in the freezer for 24 hours to at least get some minutes with my data. <snip>

Depending on how valuable your data is, you might consider a data recovery service.

Not cheap but will probably rescue more data than your method.

 

[lannister80]

And when you're done doing the "data dump" and want to hunt for files:

dd_rescue: http://www.garloff.de/kurt/linux/ddrescue/
dd_rhelp: http://www.kalysto.org/utilities/dd_rhelp/index.en.html
my rescue day: http://www.simplicidade.org/notes/archives/2005/02
foremost: http://foremost.sourceforge.net/


Compiling dd_rescue:

curl -O http://www.garloff.de/kurt/linux/ddrescue/dd_rescue-1.11.tar.gz
tar zxf dd_rescue-1.11.tar.gz
cd dd_rescue/
make