Disk utility screwed up my external USB hard disk

Discussion in 'Mac Basics and Help' started by apple.greenhorn, Aug 6, 2010.

  1. apple.greenhorn macrumors newbie

    Joined:
    Aug 6, 2010
    #1
    I have an external 500GB Freecom USB HDD with two Data partitions on it (FAT32 and NTFS). With a Windows tool, I made the two partitions smaller in order to free up some space (ca. 200GB) for an additional Mac OS Extended (Journaled) partition. This partition I wanted to create with the Mac OSX 10.6.4 Disk Utility.
    When I pluged in my USB HDD in my new iMac it mounted the two partitions, NTFS and EXT32 and the Disk Utility tool also showed the free (unpartitioned, almost 200GB) space on the HDD. Then, I chose to create a new Mac OS Extended (Journaled) partition and let the tool do it. ...which I probably shouldn't have done. Disk utility stopped and showed an error message saying that it cannot read the partitions anymore and that it needs to be closed. No partitions can be mounted anymore since then on this HDD.

    Here is the logfile entry of Disk Utility (unfortunately, it's in German):

    2010-08-06 17:27:26 +0200: Festplatten-Dienstprogramm wurde gestartet.

    2010-08-06 17:29:25 +0200: Partitionieren des Mediums vorbereiten: „WDC WD50 00AAVS-00ZTB0 Media“
    2010-08-06 17:29:26 +0200: Partitionsschema: GUID-Partitionstabelle
    2010-08-06 17:29:26 +0200: 3 Partitionen werden erstellt
    2010-08-06 17:29:26 +0200:
    2010-08-06 17:29:26 +0200: Partition 1
    2010-08-06 17:29:26 +0200: Name : „FREECOM HDD“
    2010-08-06 17:29:26 +0200: Größe : 239.83 GB
    2010-08-06 17:29:26 +0200: Dateisystem : MS-DOS-Dateisystem (FAT32)
    2010-08-06 17:29:26 +0200: Inhalte nicht löschen
    2010-08-06 17:29:26 +0200:
    2010-08-06 17:29:26 +0200: Partition 2
    2010-08-06 17:29:26 +0200: Name : „NTFS“
    2010-08-06 17:29:26 +0200: Größe : 54.08 GB
    2010-08-06 17:29:26 +0200: Dateisystem : Windows NT-Dateisystem (NTFS)
    2010-08-06 17:29:26 +0200: Inhalte nicht löschen
    2010-08-06 17:29:26 +0200:
    2010-08-06 17:29:26 +0200: Partition 3
    2010-08-06 17:29:26 +0200: Name : „Mac OSX“
    2010-08-06 17:29:26 +0200: Größe : 206.19 GB
    2010-08-06 17:29:26 +0200: Dateisystem : Mac OS Extended (Journaled)
    2010-08-06 17:29:26 +0200:
    2010-08-06 17:29:26 +0200: Medium wird ausgeworfen
    2010-08-06 17:29:30 +0200: Partitionstabelle erstellen
    2010-08-06 17:29:31 +0200: DiskManagementTool wurde unerwartet beendet. Das Festplatten-Dienstprogramm muss neu gestartet werden.
    2010-08-06 17:29:31 +0200: DiskManagementTool wurde unerwartet beendet. Das Festplatten-Dienstprogramm muss neu gestartet werden.

    Checking the HDD with the Linux tool "parted" shows the following:

    Number Start End Size Filesystem Name Flags
    1 20.5kB 210MB 210MB FAT32 EFI System Partition boot
    2 211MB 240GB 240GB FREECOM HDD
    3 240GB 500GB 260GB Mac OSX


    It seems like the Disk utility erased my MBR and somehow screwed up my NTFS partition. Also, it created a new 200MB partition called EFI System Partition. For the two other partitions no filesystem can be recognized. The third partition should come after the "NTFS" partition but it doesn't. Why did it change my existing partitions at all, when it said that it wouldn't delete the existing data?
    Trying the rescue command with parted did not succeed so far. What can I do to get back my data on the two partitions (named "FREECOM HDD" and "NTFS")?
    Any help appreciated, I am really desperate! Thanks in advance!
     
  2. Argon21 macrumors member

    Joined:
    Jun 25, 2010
    Location:
    Алейск, RUSSIA
    #2
    I would try mounting the partitions on a Linux box. Anytime you're modifying the partition structure of a drive, it is best to use only a single tool. Using two different partition tools, on two different operating systems is just asking for trouble. Was this originally using an MBR scheme? Or GUID partition scheme?

    The OSX Disk Utility can create your NTFS and FAT partitions just fine. But personally I don't like using more than one partition per physical drive. Specifically to avoid this kind of trouble. Drives are so dirt cheap these days, just buy one for each system.
     
  3. apple.greenhorn thread starter macrumors newbie

    Joined:
    Aug 6, 2010
    #3
    It used to be an MBR scheme before. Could this be the problem? How can I fix my MBR?

    But I didn't want the Disk Utility tool to modify my existing NTFS and FAT partitions at all!

    Neither of the partitions can be mounted on Linux. fdisk and parted display 3 partitions but only the EFI partition has a valid file system. Do you think it makes sense to assign the FAT32 FS to the second partition again? But what about my NTFS partition? This seems to be gone completely...
     

Share This Page