Accidentally erased partition on external drive!

Discussion in 'Mac Basics and Help' started by vmachiel, Nov 29, 2016.

  1. vmachiel macrumors 68000

    Feb 15, 2011

    so I did something stupid: I have a hard drive partitioned into two equal sized partitions (HFS+, GUID Partition). I meant to delete partition A using disk util, accidentally deleted B. I have no backup of B (I know, I know).

    Is there any free or as cheap as possible software that can scan the drive and recover as many files as possible? I just did the fastest delete so the files should still be there right? Just marked as free space?

    Thanks sooooo much
  2. thats all folks macrumors 6502a

    thats all folks

    Dec 20, 2013
    Austin (supposedly in Texas)
    Disk Warrior is great for what it does, but unformat is not one of it's tools. Data Rescue is for deleted files/drives. but buyer beware. deleting a file or volume deletes the directory. this is where Mac stores all the file metadata. Data Rescue (and others) may recover the file and file type but creation dates, other metadata including file names, are lost. yup, of all the joy that comes with an annual OS update, one thing that hasn't changed in 18 years, the file system.

    so the lesson is, back it up.
  3. organicCPU, Nov 29, 2016
    Last edited: Nov 29, 2016

    organicCPU macrumors 6502a


    Aug 8, 2016
    Yes, thats all folks is right. Before you read further. -> Eject your external drive. Then mount it read only. After that continue with whatever you try. You asked for a free Tool. Try DiskDrill. The free version should also work. Then there is ddrescue. It's not easy to get through, but a great tool. I've never used it for deleted drives, just for defective drives. Useful for you could also be TestDisk, although I didn't have so much success with it so far. Good Luck... and b....p.
  4. Fishrrman macrumors G5


    Feb 20, 2009
    As mentioned above, DataRescue.

    You will need ANOTHER drive to serve as a "scratch drive" for DR to save files as it rescues them.

    You will probably lose all previous folder hierarchies.
    You will probably lose some or all previous file names.
    This is "par for the course" with data recovery.

    But so long as you do NOTHING to the erased partition (until you run data recovery), you stand a fair chance of getting most stuff back.

    Ahem… in the future… learn about "backing up"…?
  5. organicCPU macrumors 6502a


    Aug 8, 2016
    I'm asking myself, if anybody managed to completely recover a deleted b-tree file catalog?
  6. Zazoh macrumors 6502a


    Jan 4, 2009
    San Antonio, Texas
    I've never been successful at recovering anything, even in the days of DOS when you deleting a file meant making it hidden with a $ at the front of it, Drives that spin are almost constantly being written to by swap memory. Others have, I'm just saying my experience ... because of this I have redundant backups of anything of value.
  7. organicCPU macrumors 6502a


    Aug 8, 2016
    I agree that backups are invaluable when it comes to malfunctions or user errors.
    However, digital forensics is a popular science today. Personally I could partially recover a friends crashed drive. His iMac didn't boot anymore and I could recover a 250 GB drive except 12 KB. The problem was, that parts of the b-tree and partition table were in that 12 KB. That was causing that I could only recover around 70 GB perfectly and missing another 120 GB. Luckily with a one year old backup and the recovered GBs the loss was acceptable. But if I could have managed to reassemble more of that missing Bytes, maybe from the drives Journal or with the help of some advanced algorithm, there could have been much more to recover.
    Just for fun I was also trying to recover a formatted SD card from a camera and was able to get 100% of files back. That's why I think, there must be people around, that can give ideas on recovering vmachiel's deleted file catalog, that could give him back his file names and directories. Others are deleting their secrecies with advanced deleting sequences so that no one will be able to recover afterwards. There should be something one can do besides the well known commercially tools to revert a simple delete or format of a non-encrypted drive. Any ideas?

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