Raid 1 format recovery

Discussion in 'Mac Pro' started by SDAVE, Jul 20, 2015.

  1. SDAVE macrumors 68040

    SDAVE

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    #1
    Hi All, I accidentally formatted a RAID 1 mirror (2x3TB, almost full) and need to recover the data. I haven't written anything to it yet.

    I did a quick format. Any help appreciated!
     
  2. chabig macrumors 68040

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    #2
    Since the data is still on the other drive, I think Disk Utility will repair the raid automatically as long as that drive remains part of the set.
     
  3. SDAVE thread starter macrumors 68040

    SDAVE

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    #3
    I have 2 drives in a RAID 1 and each one is a slice.

    I formatted the main partition that has both drives combined.
     

    Attached Files:

  4. chabig macrumors 68040

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    #4
    I am not a RAID expert. RAID 0 slices the data between two drives. In your case, with two 3TB drives, you would end up with a 6TB RAID volume. RAID 1 mirrors the data between two drives. Each contains a complete copy of the data. In your case, two 3TB drives would combine to form a 3TB RAID volume. When you referred in your original post to a RAID 1 mirror, I assumed the two drives were copies of each other. If, in fact, you have a RAID 0 set, you've lost everything on the RAID volume and you must restore from backup. RAID is not a backup solution. You should have a backup solution for your RAID.
     
  5. SDAVE thread starter macrumors 68040

    SDAVE

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    #5
    It is a RAID 1, aka mirrored. Should I take out one of the drives and attach it to another mac just to see if I can see the data?
     
  6. chabig macrumors 68040

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    #6
    Your data should be intact. All you need to do is add the newly formatted drive to your RAID. Here are Apple's instructions for doing that: https://support.apple.com/kb/PH5828 When you drag the new disk to your RAID, be sure to choose RAID Slice.
     
  7. chrfr macrumors 603

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    #7
    This isn't how mirrored RAIDs work. They are not backup. If you format the RAID volume, both disks are erased.
     
  8. chabig macrumors 68040

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    #8
    Good point. I interpreted the original post to mean that he formatted one disk of the pair. If he formatted the entire RAID, then yes his data is gone--time to restore from backup.
     
  9. SDAVE thread starter macrumors 68040

    SDAVE

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    #9
    But I formatted not one of the disks (the slices), but the main partition that contains both drives. If I add a new one, it will be recovered? The data is there, but Im worried I lost it because its part of a RAID even though its not RAID 0.

    Yes.
     
  10. chrfr macrumors 603

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    #10
    Your data is erased from the disks. You can do one of two things: restore from backup, or try a data recovery utility or service. You can try the standard Mac utilities, like Data Rescue, but there's no guarantee it will work.
     
  11. SDAVE thread starter macrumors 68040

    SDAVE

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    #11
    I don't have a backup :((((((

    OH MAN IM GONNA HAVE A HEART ATTACK
     
  12. chabig macrumors 68040

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    #12
    I'm sorry. I misunderstood. I think your data is gone. Without a backup, I think your best hope is one of the very expensive data recovery services. There are apps that advertise their ability to recover files, but I have no experience with them. Search the net:

    http://www.drivesaversdatarecovery.com
    http://www.cleverfiles.com/partition-recovery.html
    http://www.macintosh-data-recovery.com
     
  13. SDAVE thread starter macrumors 68040

    SDAVE

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    #13
    Currently running Stellar Phoenix and Data Rescue.
    Wish me luck guys.

    I was half asleep and running Disk Utility, a word of advice, don't do that.
     
  14. chrfr macrumors 603

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    #14
    What you really mean to say is "don't run without a backup."
     
  15. SDAVE thread starter macrumors 68040

    SDAVE

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    #15
    The whole point of raid 1 is to have a backup.

    But this is a user error.
     
  16. IowaLynn macrumors 6502a

    IowaLynn

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    #18
    In a number of cases (most) SoftRAID has been able to. The support has been outstanding from day #1.

    I tell people to use a 3-drive mirror, not the minimal. Pull one for "backup" / archive or off-site. SoftRAID has more features, faster background rebuilds, checks drive integrity during idle, use all drives in a mirror for reads so that helps performance during read IOs.

    You can download the demo, check the guides, and DO contact support@softraid.com
     
  17. chabig macrumors 68040

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    #19
    I used to run the same three drive setup using Disk Utility. It works just fine.
     
  18. SDAVE thread starter macrumors 68040

    SDAVE

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    #20
    Im in the process of recovering from a heart attack because I just lost, 900,000 files.

    HFS+ sucks. I can't even recover file structures.

    I remember back in the day I recovered an NTFS partition and I was able to bring back the file structure etc.
     
  19. chrfr macrumors 603

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    #21
    No, the point of RAID 1 is to protect against hardware failure.
     
  20. SDAVE thread starter macrumors 68040

    SDAVE

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    #22
    You're getting super technical here.

    I am asking for help. I made a mistake. Have no offsite backup.


    I was able to use some recovery apps but all the file structure is gone and file names

    this is useless.
     
  21. chrfr macrumors 603

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    #23
    This is typical of recovery from formatted Mac disks. You may want to contact a data recovery service like Drivesavers, but they'll likely be unable to retrieve anything but loose files either, and it will cost significant money.
     
  22. chabig macrumors 68040

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    #24
    He's not just being technical. He's 100% correct. I posted several links that explain why RAID is not a backup. If the loss of 900,000 files doesn't sway your opinion, I don't know what will.
     
  23. SDAVE thread starter macrumors 68040

    SDAVE

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    #25
    I may be lucky, I tried Data Rescue 4 using "lost files" not "deep scan" and it found all the structures. Cross my fingers. Going to run a full recovery now it will take 14 hours.

    Of course he is 100% correct. I am not arguing that at all.

    This was a local drive set which I never touch. I work off a RAID 6 that's running off dell servers and there's a daily tape backup done on multiple tapes. But this was an anomaly since I made the mistake.
     

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