How-to: recover a failed Lacie Big Extreme

[strus_fr]

Hi
I just recovered a failing Lacie Big Extreme 1To external disk.
Lacie Big Extreme 1To is a 2x500Go RAID0 external drive.
The issue was a clicking sound when powered up.
The steps are the following:
- Remove the HDD1 of the Lacie Big Extreme (the one next to the connectors)
- Take a 'dd' of this disk = dd1.img
- Remove the HDD2 of the Lacie Big Extreme (the other one)
- Take a 'dd' of this disk = dd2.img

Then you need to rebuild the RAID0 array which is very simple once you know the strip size, which is 256kb.
Here is the script to help you rebuild the RAID0 and which will create a alldd.img file that you will have to mount normally;

#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# deinterlace.py
#
# INTENT = This is a script for deinterlacing two raw dd images
# taken from a failed RAID 0 array into one "valid" image file
# that we hope to be able to recover data from.
#
# This is strictly experimental.
#
# Thursday, May 1, 2008 -Simón A. Ruiz
#

inputFiles = [open("dd1.img","rb"),open("dd2.img","rb")]
outputFile = open("alldd.img","wb")
chunkSize = 262144

# And, so as not to have to figure this out every time through the loop...
numFiles = len(inputFiles)

i = 0
while True:
nextChunk = inputFiles[i%numFiles].read(chunkSize)
if not nextChunk:
print 'Done! No more data.'
break
outputFile.write(nextChunk)
i += 1

outputFile.close()
for file in inputFiles:
file.close()

Once the script has done its work, just mount the dd image using:

Code:

kpartx -d alldd.img

The overall process takes approximatively 2 days (1/2 for each 500Go dd images, and 1 day to rebuild the RAID0.
Good luck!

[dmarques]

That might be good, but do not forget it will only work in some circumstances like your, and normally every case is a difference case.

[strus_fr]

For sure for this one it was good. I completely agree with you. But as you can see I specified that the issue was a clicking sound (power issue I guess or electronic issue in the MB of this enclosure) but the disks were in good health.
Also, I did not write this little script and others have succeeded, so it will work in some cases ... if you have the right chunk size! but 256kb is the good size for Lacie Big Extreme disks.
Thanks!

[fzabkar]

@strus_fr, very nice work and many thanks for sharing.

[pcimage]

Yes, nice work.