extracting data from failed raid 0

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Is it possible to extract data from a failed raid 0, and if so, how to go
about it?

tia, rbm

Re: extracting data from failed raid 0

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Depends on what failed.

If one of the drives has failed, data recovery will essentially be close to

if it was the controller, then yes, you have a chance.

A back-up scheme would have been a *necessity* for Raid 0

Re: extracting data from failed raid 0

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Thanks, that's what I thought. One of the drives did fail
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Re: extracting data from failed raid 0


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Providing you send both drives, and the RAID controller
(meaning motherboard if that's where it was implemented) if
the service center asks for it, there is a reasonable chance
a professional data recovery center can recover some if not
all of your files.

DIY?  No, if the data is valuable enough to climb the
mountain of a learning curve to DIY and buy the necessary
equipment, you'd be better off time-wise and financially to
send it to the data recovery center.

However, you might try to make the environment ideal just in
case the drive isn't totally dead yet.  For example, erratic
(dirty, low) power to the drive, or excessive temperature,
can cause a temporary problem which might even corrupt data
at the time, but if better conditions are in place the drive
might work again.  In other words, it seems you know you
have a disc subsystem problem, but since it is usually the
case that the minute details of exactly what piece of what
part failed are missing, it can be worth the time to try a
few things including placing the drive in a different
environment... but of course if the motherboard had a
built-in raid controller then it becomes more complex,
instead of moving the drives and controller you might swap
in a different PSU, try a different data cable, and point a
fan at the drive.

Granted, the drive is probably dead, but every now and then
they aren't totally dead.  In particular I've had several
instances of a Silicon Image raid controller dropping
members of the array, seemingly for no reason at all as the
drives work in another system, even hooked back up to the
same system.  It seems the board and/or controller is
susceptible to noise pickup and the quality and positioning
of the IDE cables is fairly important, as is their length.

Re: extracting data from failed raid 0

RBM wrote:
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First, you'd tell us what failed. Did the RAID BIOS report the failure ?
Did you have Windows installed on the RAID0, and booting failed.
Was the RAID a data-only array, and it has simply disappeared from
Windows ? Perhaps the Windows RAID Management software is happy with
the array, except the partition is missing.

The answer for each of those cases could be different.

These are the resources on the RAID0 drives I know about.

One drive has the odd blocks of data 1,3,5.
The other drive has the even blocks of data 2,4,6.

The "block" is some number of sectors of data. Due to that
interleaving pattern, when one drive fails, a recovered file
would have "block" sized holes punched in it. If a file fit
within a block sized chunk, it might be recovered intact.

Each drive has a "reserved sector" (actual size is 512 bytes to
64KB). The reserved sector records the array partnership, which
drive is odd and which drive is even, perhaps even their serial
numbers. There is enough info there, so that if you move the
drives from one SATA connector to another, the driver can still
figure out they're an array. The format of the reserved sector
is not standardized, so you cannot move an Nvidia array to an
Intel controller.

I'm guessing here, but presumably everything above that level
(Windows file system info) would be layered on top of that
interleaved block structure. That means the partition table
might be entirely contained on one of the drives. If the
partition table is erased, the RAID array software should
not be reporting a failure, but you may have noticed the
volume was missing in Windows. And if that was your C: volume that
you boot from, a boot failure may not mean the RAID is
failed either - it could be just the partition table is
damaged. Or some key boot file is missing, and the problem
has little to do with the fact it is a RAID0.

There is a free recovery program here, which might work
in some situations. This doesn't have its own drivers,
and would seem to rely in at least the Windows version,
on the drivers in the system. If the RAID driver won't
make the array "visible", this won't work.


There are a ton of those $39.95 recovery programs, but
who knows which of them work. There are also data
recovery firms, who would love to charge you $1000
to recover a RAID. So those are other options.


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