damians personal blog

The symptoms:
An external firewire harddrive behaves normal right after startup. But after a short time, any attempt to access the drive will result in the "rotating wheel of death" - be it the finder, diskutility or the terminal. If I wait patiently for about 20 minutes, the functionality comes back to normal, until I want to access the damaged harddrive.

Failed remedy:
DiskWarrior, which is usually quite successfull, found the disk to be "too severely damaged for repair." What now? Give up all the data on the drive? Not before having tried all available means! (And, basically, the data is still there and accessible, at least for a moment after startup).

The home-grown remedy:

• Boot the computer into single user mode (press CMD-S at startup)
• Start the operating system but stay in single user mode: % sh /etc/rc
• Connect the firewire drive and check which device number it has got:
  % ls dev (the device will have a name like disk1, the partition on it will be numbered subsequently disk1s1 and so on; usually, the partition You want is disk1s3)
• Mount the partition sudo diskutil mount disk1s3 (although You are logged in as root You still have to use sudo to make it work)
• Optionally check if the partition has mounted without troubles: % df
• Access the data You want using % cp or % rsync (I suggest % sudo rsync -avPE [SRC] [DEST] since it continues the data transfer where it has left it)
• Unmount the partition with % sudo diskutil unmount force disk1s3 if it is not responding (this may take quite a while, so you better be patient)

For me, this worked. I cannot yet tell whether it is a hardware or a software problem, but at least I got my data back.

        20.Aug.2006, 10:27 :: mac os x :: Permalink :: Comments (0)