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Possible Duplicate:
Recover Files From Formatted HFS+ Partition

On my Macbook with OS X 10.6.8, I tried to erase free space (zero out) on a pretty full 2TB external hard drive using Disk Utility.

I have done this lots of times before to free up a little more space. When I did it today, the progress message said "unmount volume", then "erasing volume"! The whole process took only 10 seconds. After that, there were 2TB of free space and all my files were missing.

Does it seem only the partition was erased since the erasing only took 10 secs? The external hard drive only had one partition. What's the best way to recover these files? Should I use a Knoppix Live CD and disk duplication? (I'm just learning now how to do this)

Edit: Looks like I erased the volume - so what's the best way to recover the data?

The log says:

2011-09-24 09:40:19 -0300: Preparing to erase : “500GBExternal”
2011-09-24 09:40:19 -0300:     Partition Scheme: GUID Partition Table
2011-09-24 09:40:19 -0300:     1 volume will be erased
2011-09-24 09:40:19 -0300:         Name        : “External”
2011-09-24 09:40:19 -0300:         Size        : 2 TB
2011-09-24 09:40:19 -0300:         Filesystem    : Mac OS Extended (Journaled)
2011-09-24 09:40:19 -0300: Unmounting disk
2011-09-24 09:40:27 -0300: Erasing
2011-09-24 09:40:51 -0300: Initialized /dev/rdisk4s2 as a 2 TB HFS Plus volume with a 155648k journal
2011-09-24 09:40:51 -0300: Mounting disk
2011-09-24 09:40:52 -0300: Erase complete.
2011-09-24 09:40:52 -0300: 
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marked as duplicate by Moab, Ƭᴇcʜιᴇ007, slhck, 8088, Nifle Sep 25 '11 at 11:43

This question was marked as an exact duplicate of an existing question.

Are you sure you clicked on "Erase free space" and not "Erase"? – slhck Sep 24 '11 at 17:18
There are two groups of people - those who do backups and those who will do. Congratulations - you just (hopefully) changed the group. – Michał Šrajer Sep 24 '11 at 17:24
This has been asked a million times here, TestDisk is always one of the solutions – Moab Sep 24 '11 at 19:05
Yeah looks like I erased the Volume (see log) – rol Sep 24 '11 at 22:32

First and foremost stop any writing on the disk until you have recovered your data.

Try these tools to check and recover your partitions:

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Welcome to Super User! Your post isn't really useful without explaining what these applications do or how to use them in this specific case. Can you add some explanation please? – slhck Sep 24 '11 at 22:10

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