Recovering a faluty RAID0

Discussions on using the professional data recovery program R-STUDIO for RAID re-construction, NAS recovery, and recovery of various disk and volume managers: Windows storage spaces, Apple volumes, and Linux Logical Volume Manager.
emiliano_it

Recovering a faluty RAID0

Post by emiliano_it » Mon Aug 20, 2012 3:06 am

---- Sorry i've posted this also in a wrong section; apologies for cross-posting ----

Hi there,

i'm trying to recover as much as i can from a faulty (R)AID0. The raid was on a QNAP TS-210 Home Nas, and the cause of its fault should be some bad sectors on the array's Disk2 (in there array there were 2 Seagate Barracuda 1TB).

This is what i did:

1. imaged the disks with RaidRecovery (i've found this before knowing about your software); Disk2 revealed bad sectors during the imaging process but the process ended successfully;
2. because of the bad sectors may prevent the array to be recognized, i've tried to scrub Disk2 using HDD RAW Copy, to obtain an image without any bad sector (but, of course, with data loss)
3. copied back the images to actual (new) HDDs (using the same HDD RAW COPY tool
4. tried a LOT of softwares (RaidReconstructor, and many others) but none of them could even recognize the array
5. found and used the DEMO version of R-Studio and following the instructions (working with RAID etc.) i was able at least to see the correct filenames (Folders + Files) that were on the NAS before the disaster, this is what i did:
a. create a new Virtual Block RAID
b. added the 2 disks in the correct order
c. set the RAID parameters as follows:
- Type: RAID0;
- block size: 64KB (should be correct as QNAP uses mdadm for software RAID0, but may be wrong)
- block order is set on: Default (with no other selection possible)
- number of rows: 2
5. The final result (after the scan etc) is the program showing:
- Extra Found Files (in dark green)
- Recognized4 - Ext4 - 2.02 GB - 1.82TB
6. Opening the list of found files and trying to preview anything didn't worked

Probably i've done something wrong with the RAID params? Or it's simply unrecoverable? Of course all of this is only to clarify if R-Studio could work on this: in this case i'll be more than happy to buy a valid license.

Thanks in advance,
Emiliano

Alt
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Re: Recovering a faluty RAID0

Post by Alt » Mon Aug 20, 2012 4:17 am

If the bad blocks are somewhere in the middle of the disk or at its end, you should be able to recover most of your data.
Given that the images of the disk are correct, my understanding is that something wrong with the RAID parameters. If there are large jpg files (more than blocksizex2) in the Extra Found Files, you may try to preview them. If they appear "striped", most likely the problem is with the block size.
You may also try to find the RAID parameters manually if you have some understanding of the Ext4 file system. This article, although about RAID5 with the NTFS file system, may give you some clues: Finding RAID parameters.

emiliano_ita

Re: Recovering a faluty RAID0

Post by emiliano_ita » Mon Aug 20, 2012 4:42 am

Thanks for your reply and advice. I'm definitely not an expert in filesystems-related things (all i know comes from the readings i did to try solve this!). It could be useful for me to know if the problem could be restricted to the block-size or there are other params (i.e.: the offset etc.) to care about.
I've seen the NTFS doc but i think that my actual skills are not enough to allow me to replicate the process to the EXT filesystem.

Right now i'm doing another test adding not the whole drive but only a selected partition and see what happens.

What do you think i can try next?

Thanks a lot for your help,
Emiliano

Alt
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Posts: 2271
Joined: Tue Nov 11, 2008 2:13 pm
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Re: Recovering a faluty RAID0

Post by Alt » Tue Aug 21, 2012 8:43 am

The only suggestion I have is to play with the RAID parameters and disk order.

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