External drive data lost??

[applez23]

I have a Fantom Green Drive 1TG that was running on OS 10.6 until my colleague attempted to access the files from a PC. I can't honestly remember how this drive was formatted, though I had thought initially I intended to use it on both Mac and PC and had formatted it accordingly. Long story short, the drive was not showing up on the PC, so colleague found a forum somewhere that indicated he should partition the drive in order for the PC to assign a drive letter to it.

Now the drive shows up on the PC, but won't read - a message pops up that the drive must be formatted. I tried reading it through Mac, but while it sees the drive it says it must be repaired. On trying disk repair, I get a message that the drive cannot be repaired, to backup data and reformat.

There is a good bit of very important data on this drive - has it been totally lost or is there someway to recover the data from the netherworld it seems to be in currently? Thank you!

 

[Tumbleweed666]

There is a good bit of very important data on this drive - has it been totally lost or is there someway to recover the data from the netherworld it seems to be in currently? Thank you!

Not important enough to back it up before you leta klutz loose on it though ?

All you can do is try one of the data recovery tools, there are quite a few out there that will tell you what can be recovered for free before you pay for it.

I would try Disk Warrior or Data Rescue 3 for starters. You could also try tools that run on a PC, you'll have to google for those.

Odds are if only a quick format was done the data is there and is recoverable.

 

[snorkelman]

I'm assuming they've tried to access an HFS partition then repartitioned it as NTFS/FAT32

GUI based
Disk Drill is one commercial option. From what i could see it seems to be able to retrieve info better than DiskWarrior when it comes to drives that have been repartitioned. Haven't tried it in pro mode though so cant vouch for any data it actually writes.

Terminal based
Other option would be to use open source testdisk together with pdisc

That's terminal based so you need to be really careful with that method (and the end results might still need a run through Diskwarrior to repair the recovered partition before you can actually mount it and access the data).


If you manage to do it properly then TestDisk/Pdisc does work, I just repartitioned one of my spare HFS drives as FAT32, ran TestDisk to get the start sector of the missing partition along with its size, entered that info using Pdisk and wrote it out to the drive. Missing partition then returned but still needed a run through disk warrior to complete the repairs. Took around 15 mins in total


If the data you're missing is valuable then I'd suggest the following:

1 take the external drive that has your missing data and put it safely to one side. Don't try to write to it, format it etc.

2 get hold of another external drive set it up as Mac HFS format and write some test data to it (videos, photos, music, a couple of application dmg files etc)

3 trash that drive by repartitioning it as FAT32

Then practice your partition recovery on that one (confirm the music tracks n videos play and the dmg files mount etc once its recovered) and then repeat several times before letting yourself loose on the important one

This page has some info on TestDisk/Pdisk along with a download link for TestDisk

http://perrohunter.com/repair-a-mac-os-x-hfs-partition-table/

 

[Fishrrman]

There's another important lesson here.

That is:
If you are going to store important Mac data on an external drive, DO NOT use a "cross-platform" formatting scheme.

That is to say, keep your important Mac data ONLY on an HFS+ formatted drive that will never be "touched" by a PC.

All too often, I've seen cases where data stored on a cross-platform formatted drive was connected to a PC, and --- POOF! --- the drive couldn't be read on a Mac afterwards.
Hey --- isn't that exactly the problem you're having right now?

Don't do it in the future!

If you need "cross-platform compatibility", use a THIRD drive (cross-formatted) to move stuff around on. Could even be a large-capacity USB3 flashdrive.

As to getting the data back:
As mentioned above, SOMETIMES DiskWarrior can help. Realize the DW is designed to do only one thing -- repair drive directories. It might help you, it might not.

You may have to "go beyond" the directory, and use "data recovery" software (such as DataRescue3).

But be aware that in some cases, usually where the drive can't even be mounted on the desktop, even data recovery apps like DR3 come up short.

There is still hope if DR3 can't access the drive "as it is now".
It's not for the faint-hearted, but it worked for me when I couldn't get to data any other way.
I simply re-initialized the drive. Yes, that's right -- re-initialized it. VERY IMPORTANT: I DID NOT choose to "zero out" any data, just did a quick re-initialization, which wipes the old directory (not the data) and installs a clean directory.

After doing this, Data Rescue could now "see" the presence of the drive (since it would mount on the desktop, but show up as "empty").
But the drive WASN'T "empty" -- only the directory was. The actual _files_ were still out there, on the platters.
And DR could then "find them", scavenge them, reconstruct them, and save them to an extra "scratch drive".
Be aware that even if Data Rescue works, you're probably going to lose file names and folder hierarchies. This is de riguer for data recovery.

 

[applez23]

Thanks everyone for your input. Disk Drill worked and the files were recovered.

 

[snorkelman]

good to hear it