Erased external hard drive by mistake

Discussion in 'MacBook Pro' started by Bokes, Oct 31, 2014.

  1. Bokes macrumors 6502

    Mar 4, 2008
    I recently started erasing an external Hard Drive using Disk utility.
    About a 1/4 of the way through the process I realized I highlighted the wrong drive. I quit out of the process.

    I am not sure how much of the 3 TB Hard drive was erased.
    The process line was about a 1/3 of the way.

    The drive shows up in Utility, but will not mount to the desk top.

    I am currently running Data Rescue 4 Deep Scan.
    It is scanning- but gives me 12 days remaining until scan is complete.

    Anyone use Data Rescue?
    Is this normal? 12 days to scan?

    If in the end data Rescue works- so be it, but
    Is there a faster way to perform this task?
  2. snaky69 macrumors 603

    Mar 14, 2008
    Doing a simple erase usually deletes the index from the hard drive, the data itself is intact, the hard drive simply doesn't remember where it is.

    If you're lucky data can be salvaged, but it can get expensive quick.

    Can't say I've ever had to use Data Rescue, so I can't comment on that.
  3. Fishrrman macrumors Pentium


    Feb 20, 2009
    My advice (take it for whatever it's worth)

    Let DataRescue run for now.
    A "lot of data" on the damaged drive translates to "a lot of time" for which to scan it.

    Hmmmm..... you wrote:
    "I recently started erasing an external Hard Drive using Disk utility."

    IF you were using the "zero out" option (and it sounds like you were), I --DON'T-- think DataRescue is going to be able to recover that data, because it has essentially been -replaced- by NEW data (even if the "new data" is only random zeros and ones).

    (Aside: even a "professional data recovery" outfit probably can't get zero'ed-out data back for you. They may just recover the 'zeros and ones", so to speak.)

    IF you DID NOT zero-out the data, DR has a fairly good chance of getting that data back.

    In the future, DON'T "zero out" a drive if it's not absolutely essential. You may be learning why it ain't such a good choice right now.

    Having said that:
    If push comes to shove, and DR is having trouble trying to "digest" the remaining contents of the drive, you could try this:
    1. Re-initialze the drive (yes, you're reading that correctly), BUT, DO NOT choose to zero it -- just do a "quick erase" so that the old directory is replaced by a clean one (with no data entries).
    2. NOW "aim" DR at the drive, and let it go.
    3. DR doesn't need the directory -- it can go "around it", and go "straight to the platters" of the drive. It will scavenge each sector, collect what it finds, and try to reassemble it into meaningful files.
    4. You WILL need ANOTHER drive to serve as a "scratch drive" so that DR has a place to store all the "found data".
    5. You almost certainly are going to lose all previous folder hierarchies, and probably all previous file names. This is "par for the course" with data recovery, since folders and file names were a "construct" of the previous directory which is now gone.
  4. Bokes thread starter macrumors 6502

    Mar 4, 2008

    I do not believe I zero'd out that drive.
    I did not select a secure security option- I just clicked on erase.

    I'll just let rescue run in the background for now.

    The erased external drive was a back-up drive- so i still have most of the files on my main drive- but there are several client QT files that I moved to this Back-up drive to free up space. Data rescue claims they can recover QT files- so hopefully it works.

    The estimate is down to 8 days now....(?) so maybe the scan will go quicker than originally thought.
  5. cjmillsnun macrumors 68020

    Aug 28, 2009
    If you only have one copy of something, then it is not backed up. Doing that with client files is not wise. I have 2 external drives and a RAID5 NAS that I place client files on.
  6. Bokes thread starter macrumors 6502

    Mar 4, 2008


    luckily the client files I lost on the back-up drive are from projects completed 3+ years ago. So the likely hood of the clients contacting me for more copies are slim.
    That said- I have had some clients come back to me many years later in the hopes that I saved the project.

    Of course- with my luck lately- I'll get a call next week from one of these old clients looking for these files.

    Data rescue still chugging along......

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