Advice on rescuing LaCie Big Disk (this is not a bug report nor contribution, respond only if willing)

[Manca Weeks]

Hi,

first and foremost - THANK YOU - for creating ddrescue. Me and many
of my customers are eternally indebted to you.
Let me know if there is a way for us to donate funds to the project.

I have a LaCie Big Disk with one drive working (I believe the RAID
scheme is striped and hardware based). I will try to swap the drive
board (don't know the proper handle -the chip that interfaces between
the drive hardware and the ATA interface) from the working drive to
the non-working drive after I have made an image of the one that
works since the drives are identical.
It sounds (from my other drive rescuing experiences) like a drive
with a power issue, not a mechanical problem. So I hope switching the
board will allow me to grab the data from the other drive without too
much trouble.

I have successfully recovered many drives using ddrescue before, but
all were on single drives, so the process was quite simple. I operate
mainly in the GUI of OS X so I am only familiar with basic unix
concepts and commands.

I have another suitable healthy drive I may be able to use to attach
to the BigDIsk hardware in place of the damaged one, but I am
uncertain about how to properly duplicate the RAIDed data to the
replacement drive. The model is only slightly different and the
manufacturing date is merely months apart, same size. I would like to
figure out a way to fool the RAID hardware to not notice the drive
swap.

Right now I am imaging the Apple HFS part of the healthy drive in the
RAID, I am uncertain where the RAID data is kept - I assume within
the HFS partition, but I realize I could be completely wrong.

If you are willing to help, please respond and I will provide
whatever additional details you need to help me figure this out.

If there is an existing thread, forum or any other resource detailing
a case like this, please direct me to it. This is a bit deeper than
my usual web searches, so I am not at home finding the information.

I am eternally grateful for ddrescue as is and will not be offended
if you have better things to do than help a newbie.

Thanks for your hard work.

Manca Weeks

http://overnightmac.com
888-308-9603


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[andrew zajac-2]

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Hi Manca.

What does the partition table on one of the drives look like?  I don't quite know what you mean by "I am imaging the Apple HFS part of the healthy drive in the RAID".  I am assuming that this array is striped and not mirrored, which means that you would need both drives to use the array (you need to assemble the array into one block device and then mount the filesystem on it). 

If you are able to image both drives, then everything should work out.  Image them however you want - to separate drives or as two big files on one big drive.  Assuming the array is not corrupt, you will be able to mount the filesystem on no matter where the image is.  If you have another drive and make a perfect image of the original disk and plug it into the enclosure, it will probably work.  If not, you can always assign the partitions on the images to loop devices and then use mdadm to assemble the array using the loop devices (on Linux - don't know about OS X.)

Cheers!

Andrew Zajac

---

From: Manca Weeks <manca@...>
To: bug-ddrescue@...
Sent: Monday, October 5, 2009 9:52:01 PM
Subject: [Bug-ddrescue] Advice on rescuing LaCie Big Disk (this is not a bug report nor contribution, respond only if willing)

Hi,

first and foremost - THANK YOU - for creating ddrescue. Me and many of my customers are eternally indebted to you.
Let me know if there is a way for us to donate funds to the project.

I have a LaCie Big Disk with one drive working (I believe the RAID scheme is striped and hardware based). I will try to swap the drive board (don't know the proper handle -the chip that interfaces between the drive hardware and the ATA interface) from the working drive to the non-working drive after I have made an image of the one that works since the drives are identical.
It sounds (from my other drive rescuing experiences) like a drive with a power issue, not a mechanical problem. So I hope switching the board will allow me to grab the data from the other drive without too much trouble.

I have successfully recovered many drives using ddrescue before, but all were on single drives, so the process was quite simple. I operate mainly in the GUI of OS X so I am only familiar with basic unix concepts and commands.

I have another suitable healthy drive I may be able to use to attach to the BigDIsk hardware in place of the damaged one, but I am uncertain about how to properly duplicate the RAIDed data to the replacement drive. The model is only slightly different and the manufacturing date is merely months apart, same size. I would like to figure out a way to fool the RAID hardware to not notice the drive swap.

Right now I am imaging the Apple HFS part of the healthy drive in the RAID, I am uncertain where the RAID data is kept - I assume within the HFS partition, but I realize I could be completely wrong.

If you are willing to help, please respond and I will provide whatever additional details you need to help me figure this out.

If there is an existing thread, forum or any other resource detailing a case like this, please direct me to it. This is a bit deeper than my usual web searches, so I am not at home finding the information.

I am eternally grateful for ddrescue as is and will not be offended if you have better things to do than help a newbie.

Thanks for your hard work.

Manca Weeks

http://overnightmac.com
888-308-9603


_______________________________________________
Bug-ddrescue mailing list
Bug-ddrescue@...
http://lists.gnu.org/mailman/listinfo/bug-ddrescue

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Hello,

Manca Weeks wrote:
> first and foremost - THANK YOU - for creating ddrescue. Me and many of
> my customers are eternally indebted to you.
> Let me know if there is a way for us to donate funds to the project.

I am very glad to know ddrescue helped you to save your data. :-)

You can donate via PayPal here
https://www.paypal.com/xclick/business=ant_diaz%40teleline.es&no_note=1&tax=0¤cy_code=EUR.
Thank you very much for contributing a donation to the project.


> I have successfully recovered many drives using ddrescue before, but all
> were on single drives, so the process was quite simple. I operate mainly
> in the GUI of OS X so I am only familiar with basic unix concepts and
> commands.

I have no experience with OS X, so I can't improve the advice given by
Andrew Zajac. But I'll answer any question if I know the answer.


Best regards,
Antonio.


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