SB750 Migration deleted data with RAIDXpert

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planq

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I started with a 3 drive RAID 5 set up using the SB750. I recently got another drive to add to it, and used the migration function in RAIDXpert's web interface (perhaps I should have only looked for an "expand" option). It popped up with a "this drive will be erased" notification, which I thought was for the drive I was adding with the migration because all information about migrations in the help didn't indicate that the RAID drive would be erased (I read the whole section). After the requested restart I noticed that my RAID was unformatted. I have done nothing to it since.

Is there a way to undo the migration or somehow salvage my data? It all seemed accessible before the restart so I doubt everything has been overwritten; I am hoping it's just hidden. I didn't have a proper backup of my data, and now I'm regretting that I didn't.

Any help would be appreciated.
 
Solution
In some cases it makes sense investing in a proper backup solution - RAID is not a backup, and some "consumer-grade" RAID5's are less reliable than a single disk without any redundancy.

2TiB threshold means you exceed 48-bit LBA adressing. You need 64-bit LBA to go beyond 2TiB arrays. With software RAID, you only need 48-bit LBA as long as the individual disks are less than 2TiB large.

What you really want of course, is something like ZFS to solve your storage problems. It would probably take some multiple years until 'common' people get to use such technology, to basically make them never lose data anymore.

planq

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Oh, hopefully some useful information: the unformatted RAID is the size of the sum of the 4 drives (so Windows is counting the parity space as useful storage instead of parity... and yes, the new array is still a RAID 5).
 

dicktherick

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Hello,

the same thing happened to me. Coming from 3 x 1TB RAID5 i wanted to expand the Logical Drive using RaidXpert.
Theoretically, expanding a logical drive should work without losing any data.

BUT!

crossing some TB-Barriers (2TB in my case) changes the Block-Size of the RAID-Volume. I found that hint in some PDF Manual to the RaidXpert Software (but can't find it anymore right now).

In the Manual it said, that you should re-create the volume when crossing the 2TB...(4TB was the next Barrier)
But the RaidXPert Software doesn't seem to know about that fact - sadly.

For me too, the data was still accessible before the reboot. But after the reboot everything was gone.

I spent hours with different NTFS File Recovery tools. Some of those still saw the File-Handles and the Data, but after recovery I had to find out, that all the Data was mixed up an corrupt.

So no luck for us...

In some cases it makes sense spending a few hundred Dollars in Adaptec oder LSI RAID Controllers... ;)


CU


Richard
 

sub mesa

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In some cases it makes sense investing in a proper backup solution - RAID is not a backup, and some "consumer-grade" RAID5's are less reliable than a single disk without any redundancy.

2TiB threshold means you exceed 48-bit LBA adressing. You need 64-bit LBA to go beyond 2TiB arrays. With software RAID, you only need 48-bit LBA as long as the individual disks are less than 2TiB large.

What you really want of course, is something like ZFS to solve your storage problems. It would probably take some multiple years until 'common' people get to use such technology, to basically make them never lose data anymore.
 
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planq

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Thanks for the input.

I think I have some good news about my data. After ignoring my missing data for a while, I finally started poking around with it some more. I got access to another computer with 4 SATA ports on it, hooked all the drives up to it, and used File Scavenger. It has a RAID reconstruction feature where you define the RAID type, disk order, parity rotation, block size and first sector used on each disk. I basically had all the information because I never touched my original RAID setup after the data went hiding. For reference, most of those parameters work as default except the block size is 128KB; I already knew the disk order and I think I remember originally defining the block size as 128.

It seems to see everything just fine, but I've only used it in demo mode so far (which only allows you to recover files up to 64KB, but also lets you preview any pictures which helps with data verification). I first tried it with a 64KB block size (default), which still recovered small text files, but no image previews worked (not even on a 24KB picture I found). The image previews work with a 128KB block size (I checked on multiple images > 1MB including an uncompressed bitmap).

Now I have two options to get my data back: finish the job with this program (easier but it's $185.00 for the version I'd need... although it's a handy program), or try to define the RAID properly on the original "controller" (cheaper but riskier). How easy is defining a new RAID while keeping data (specifically with the SB750)? I know the safest way is to image the drives before messing with the controller, but I just don't have that much free space handy.
 

Divien

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Hello there! Stuck on the same problem. On SB850 after migration raid0 from 2x640gb hdds to 2x640 + 2x750 (cut 640 and stay free 110) cant load the system, the BSOD says 0x000000ED and raid0 is unformatted. And yes, im not save my data. Stupid.

Do you try to just redefine your raid? What was the result??
Answer please )


 

tyg5

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Jan 25, 2012
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Divien,
Did you get a solution? I have a similar, slightly different problem and I'm not sure which path to go down?


 
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