Accidental Reformat... any suggestions?

Hello everyone! I’m a noob to Mac – just got my first MBP about a week ago.

I have two external hard drives – 500 GB and 1 TB. I wanted to reformat both of them to HFS+ so I could use them with my Mac.

I transferred about 78 GB of data from the 500 GB drive to the MBP by connecting the hard drive to my old Vaio laptop via USB, then connecting the Vaio laptop to the MBP with an Ethernet cable.

Now comes the stupid part. I could only fit 78 GB of data onto the MBP, so I decided to reformat the 1 TB drive to HFS+ and transfer the first 78 GB of data to the TB drive.

After a few frustrating hours of trying to reformat the TB drive to HFS+, I plugged in the 500 GB drive and was overjoyed to find that it reformatted to HFS+ quite nicely. I transferred my 78 GB of data onto the 500 GB drive – and then realized what I had done.

I still had 300 GB worth of data on the 500 GB drive before reformatting it.

I tried to plug the 500 GB drive up to my Vaio and see if I could run some recovery software on the drive, but it wouldn’t even see the drive. So I got MacDrive and retried – and the recovery software I got says either it’s not a logical drive or the data is too far corrupted (sorry I forgot the name… and I’m at work without the MBP).

Any suggestions on how I can recover the data? The data is really important to me – a few years’ worth of digital photos and various video/audio files for my video editing hobby.

OK, that's pretty bad.

In theory, unless you did a low level reformat, about 200GB of the data could be in tact. However because of the way in which data is written, in theory all of the previous data could have at least some level of corruption, especially if the previous format was NTFS. If it was FAT 32, there is a slightly better chance of recovery.

If the data is REALLY important, it might be worth taking it to a specialist, but if you want to take a risk, I'd reformat it back to it's original format and get the recovery software to look at it then, because this way at least the recovery software knows what format the original files were in.

Either way, every time you write any data to it (including changing the file allocation tables) you risk losing more data.

Zoolook said:

OK, that's pretty bad.

Click to expand...

That's what I was afraid of

I didn't want to reformat it back to NTFS and risk b0rking it even further. So I guess my only two choices now are to take it to a specialist (who knows where to even find one lol) or format it back to NTFS and take my chances...

mina said:

That's what I was afraid of

I didn't want to reformat it back to NTFS and risk b0rking it even further. So I guess my only two choices now are to take it to a specialist (who knows where to even find one lol) or format it back to NTFS and take my chances...

Click to expand...

It could be expensive. Sorry to hear your story.

Your only choice now is to go to someone like www.drivesavers.com, which is very expensive.

Very expensive is right!

They quoted me a range of $400 to $2300 to recover my data. x_x

If I understand your story correctly, you ended up formatting the 500GB from a Windows format to HFS+ when you really wanted to format the 1TB drive.

How long did the actual formatting take? If it took a very long time, then I believe you have done a low level format and the data would be erased in that case. I can't help but think this is the case. If so, I don't think you can recover the data.

If the format took only seconds, then OS X simply altered the beginning structure and currupted or removed the file pointer information for Windows. I doubt even this is recoverable but just maybe. I would look into a drive recovery business that deals with both Macs and PCs. If they could recover the file pointers, then they might be able to recover some of the files.

As a very last resort, if you are convinced you are not going to use a media recovery business, then you can try what Zoolook suggested and reformat the back to the format it was previously. You would want to choose a "Quick Format" which should not do a low level format. (I'm guessing in this case because I don't really know what it will do when it sees a formatted disk it does not under stand.) You would then try your PC recovery software on the drive. Note that copying that 78GB back to the drive has messed things up even more. I must admit to having doubts about this wacky idea, but you are in an extreme position here.

I hate to be gloomy, but it sounds to me like you are going to have to continue life without that data.

xstep said:

If I understand your story correctly, you ended up formatting the 500GB from a Windows format to HFS+ when you really wanted to format the 1TB drive.

How long did the actual formatting take? If it took a very long time, then I believe you have done a low level format and the data would be erased in that case. I can't help but think this is the case. If so, I don't think you can recover the data.

Click to expand...

Yes... that's exactly what happened.

The actual formatting took less than a minute - thus I can only conclude that it was a low level format. That was why I was really hoping that I could still recover the data somehow.

The lady I spoke with at the data recovery place said that this kind of thing can actually be covered with renter's insurance. Has anybody else heard of that before?

I would expect a low level format of a 500GB drive to take much much longer than that.

I've don't know abou the insurance think. Phone and ask.

Oops sorry - typo. I meant it was a high level format because it took less than a minute.

Can you tell I'm a little bit stressed out about this situation? LOL

I would do some research on how the reformat rewrites the Table of Contents (this, in theory, is the only thing that is erased on a high level reformat). If you can find the disk location where the TOC ends, and use a terminal command of some kind to strip the 500 GB disk from that TOC endpoint to the end of the disk (writing it to the 1TB disk as it goes), you may be able to get some of that data back.

Oops I've already reformatted it to NTFS and it's currently being scanned by a data recovery program at the moment. I'm feeling a bit hopeful because after I switched the drive back to NTFS, the program saw it as a logical drive. Thus, it is now scanning through to see if there's anything it can save. It's going a bit slow so I'll let it run through tonight to see what it comes up with.

Thank you for all your suggestions, guys!

I think you're all forgetting that she has also written 75GBs of data to the newly formated drive. Because the new format was different, this could mean much of the original data is lost, because of the way data is written.

Say this is the original drive


|xxxxxxxxx--xxxxxxxxxxxxx------xxxx--xxxx|

x = used space
- = free space

It gets reformatted

|----------------------------------------|

75 Gigs of data is written, plus indexes in a different file format

It could be

|xxxxxxx---------------------------------|

or more likely

|x---------xx-------x------xx--------x---|

It depends on the file typs and sizes of the original and new data. If the original 300 gigs was 3 100 gig HD movies, then forget it. If it was tens of thousands of little image files, then many could be recovered. Anything in between is a complete lottery.

Again, if the new data is just a few really large files, then recovery of the previous data is more likely, but if it's 10,000 small files, it gets tricky.

Hey Zoolook!

I tried your suggestion last night and it came up with a few files that looked promising. That was with a high level scan. I started a low level scan before leaving for work this morning, so hopefully I'll come up with even more stuff when I get back home.

The good news is that I found out I *did* backup my pictures. Interestingly enough, the backed up pictures were part of the 78 gb that I had successfully transferred over to the MBP. It was hiding in some other folders that got saved with a different name!

Woohoo.

File recovery definately works better in the original file format, so good luck with the low level scan.