[ltp] HDD emergency repair (howto)

[Ted Ghose]

Richard,

awesome, I've two of those... let me try!

Appreciate it a lot

thanks

-tg-

On 5/6/09, Richard Neill <rn214@hermes.cam.ac.uk> wrote:
> Dear All,
>
> I've just saved a friend's SATA notebook disk, and thought it might be
> worth writing up a brief account.
>
> Symptom:
>    Laptop wouldn't boot at all, stalling at the first BIOS screen.
>    HDD wasn't spinning.
>    Unplugging HDD allowed the laptop to boot via live-CD.
>    => HDD faulty.
>
> Confirm:
>    There is nothing else that can be done with this disk. Professional
>     data recovery is too expensive. So OK to take a risk.
>
> Open the disk:
>    Carefully, using a torx screwdriver.
>    One screw is hidden under the label.
>    Clean room would be nice, but I don't have one
>
> Discovery:
>    The head appears to have cold-welded itself somewhere in the
>    middle of the disk. The disk can't spin at all. This is the
>    second time I've come across a 2.5" disk with this problem.
>    User says it wasn't mis-treated.
>
> Solution:
>    Carefully, without touching the platter, use a fingernail to
>    force the head back into the parked position. Some considerable
>    force (perhaps 10 newtons?) is required.
>    Then quickly re-assemble drive before too much dust gets in.
>
> Recovery:
>    Put disk into thinkpad. Boot thinkpad from a live CD. (Mandriva 2009).
>    Fortunately, the "dead" disk spins up.
>    In the live-CD environment, add the package repositories, and install
>    ddrescue.  (Note there are 2 similar programs: ddrescue and dd_rescue.
>    I've had success with both.)
>
>    Mount an external USB HDD. Let ddrescue do its stuff:
>      ddrescue /dev/sda sda.img ddrescue.log
>    After about 24 hours, ddrescue has recovered all 80 GB of the disk,
>    excepting about 5 MB.
>    Also, save fdisk info:
>      fdisk -l /dev/sda > sda.fdisk.txt
>
> Extract partition 1.
>     dd if=sda.img of=sda1.img bs=512 skip=63    #value depends on fdisk.
>
>     Mount the partition loopback:
>       mount -o loop,ro sda1.img /mnt/tmp
>
>     Note: it's supposed to be possible to do
>        mount -o loop,ro,offset=32256 sda.img  /mnt/tmp
>      but I found it didn't work.
>
>     Note 2: It would normally have be easier to directly extract
>     the partitions one at a time, at the ddrescue stage,
>     But in this case, the offending disk is a Windows XP
>     system, and I want to be able to re-image the OS onto a new
>     drive. A filesystem-level copy won't work here. [In Linux, it's
>     easy: just fdisk, mkfs, rsync, then fix fstab and install grub]
>
> Recover data:
>     copy stuff from /mnt/tmp
>
> Re-image to a new disk:
>     Plug in new HDD, boot from liveCD.
>     dd if=sda.img of=/dev/sda
>
>
> I hope that's useful to someone...
>
> Morals of the story:
>    (1) ddrescue is really useful.
>    (2) Linux can do almost anything.
>    (3) Even a totally stuck HDD can be saved without needing a cleanroom.
>    (4) Having a USB-SATA adapter would be useful.
>
> Best wishes,
>
> Richard
> --
> The linux-thinkpad mailing list home page is at:
> http://mailman.linux-thinkpad.org/mailman/listinfo/linux-thinkpad
>


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