Dell Perc H710 RAID-6

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.
RForce
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Dell Perc H710 RAID-6

Post by RForce » Wed Feb 21, 2018 2:35 pm

I was able to quickly assemble the RAID with R-Explorer using default settings but am unable, thus far, to find the appropriate config is R-Studio. Anyone have a way to interpret these settings into R-Studio speak?
RAID-config.png
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RForce
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Joined: Wed Jul 09, 2014 9:05 am

Re: Dell Perc H710 RAID-6

Post by RForce » Thu Feb 22, 2018 11:48 am

Okay, so I've found the issue I was having with R-Studio. Apparently, R-Studio will only work with 1 missing disk. If I add the stale clone of drive 4, the partition label suddenly pops up, but as soon as I disable drive 4 or swap it with missing disk, first BS is garbage.

RForce
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Re: Dell Perc H710 RAID-6

Post by RForce » Fri Feb 23, 2018 1:37 pm

Any chance that we will see R-Studio support 2 missing drives in a future update?

Alt
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Re: Dell Perc H710 RAID-6

Post by Alt » Sat Feb 24, 2018 6:52 am

Actually, we tested a 4-disk mdadm RAID6 with 2 disconnected disks, R-Studio worked fine.

RForce
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Re: Dell Perc H710 RAID-6

Post by RForce » Wed Feb 28, 2018 9:07 am

Weird, with the scenario posted above, I can only get R-Studio to load the file structure if I add the stale drive into to the mix. As soon as I drop the 2nd drive, the BS turns into a garbled mess. Any chance that R-Studio has a flaw for larger RAID 6 arrays or has issues with hardware RAID-6's? If I can get a chance today, I'll post the R-Studio screenshots to show what I'm seeing.

RForce
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Joined: Wed Jul 09, 2014 9:05 am

Re: Dell Perc H710 RAID-6

Post by RForce » Wed Feb 28, 2018 11:52 am

Okay, I've taken a bit more time to try and make sense of things. Although the drives are from a Dell Perc controller, I'm able to use mdadm to read the meta data enough to determine the order in which the drives failed.

Drive 0 failed first, then drive 4, then drive 1. So, the best combination for the RAID should be with 0 and 4 missing. With R-Explorer, I added the drives and missing drives in the correct order, set it to RAID-6 and the file system came up right away.

With R-Studio, I get this:
R-Studio-RAID6-drives-0-4-missing.png
When I look at the boot sector with this config on R-Studio it looks like garbage:
R-Studio-RAID6-drives-0-4-missing-BootSector.png
But, when I look at the boot sector with the exact same config on R-Explorer, the boot sector looks fine:
R-Explorer-RAID6-drives-0-4-missing-BootSector.png
If I enable drive 4 with R-Studio and do any other combination of missing drive, the partition does show, but every variation shows different results.
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Alt
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Re: Dell Perc H710 RAID-6

Post by Alt » Thu Mar 01, 2018 10:18 am

Are those disks or their images still with you? It's a rather important question.

RForce
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Re: Dell Perc H710 RAID-6

Post by RForce » Fri Apr 20, 2018 10:42 am

Alt wrote:
Thu Mar 01, 2018 10:18 am
Are those disks or their images still with you? It's a rather important question.
Sorry...I didn't catch your response. But, yes they are still with me. Just finishing up the recovery now. Only wish that R-Studio would have an option to unselect skipped files during the copy process. It copied about 5TB of data to the destination when Windows decided to reboot. So, now after running another 14 days, my destination drive says that there is 1.04 TB of free space and R-Studio is saying that there is 5.92 TB left to copy. It will suck to have spent the better part of a month copying the files over to find out that I have to do it all over again.

Edit: Yes, the update fixed the issue.

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