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Data recovery and disk repair questions and discussions related to old-fashioned SATA, SAS, SCSI, IDE, MFM hard drives - any type of storage device that has moving parts
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RAID Recovery with 24 3TB drives

May 15th, 2017, 11:38

Hello

I have 01 RAID6 with 24 3TB drives (SuperMicro array).

His technician has regenerated the RAID (24 hours). then he couldn't see data.

I have 3 questions:

1. How to connect 24 drives to PC with SATA
2. Is there a way to regenerate the RAID and recover data in a such case
3. If yes, Is there a way to speed up the array analyse in order to detect the RAID parameters.

Thanks for the help in advance.

Kind regards

Re: RAID Recovery with 24 3TB drives

May 15th, 2017, 11:45

First off, if you're serious about getting that data back you should really consult a professional data recovery company. Automatic recovery is not likely to stand a chance (actually stands no chance) and with a 24 drive RAID it'd take a lifetime to figure out the settings just using brute force methods. You'll really need a professional who understands file structures to figure it out.

Where are you located, perhaps we can recommend someone in your same country who can look at it.

EDIT: I just realized you are offering professional recovery, sorry I didn't recognize the username.

Re: RAID Recovery with 24 3TB drives

May 15th, 2017, 11:54

Here's some answers to your questions:

1. Get one or two rackmount SATA/SAS drive enclosures with external SFF-8088 connections. These are often daisy chainable so you can connect an SAS card to the first one then daisy chain any subsequent ones until you have all drives connected. I use a few enclosures from Rackable systems

2. Maybe, but you'll need to figure out exactly what happened. I'd start by looking at the drives in hex to be sure they weren't all zero filled when the tech re-created the RAID. It's possible he "sanitized" all the drives.

3. Forget automatic analysis. It rarely works for 3-4 drive arrays, it'll never work for an array that big. It'll need to be done manually.

Re: RAID Recovery with 24 3TB drives

May 15th, 2017, 15:42

Buy Areca HBA controller (arc-1320-ix16) you can connect 16 sata hdd simultaneously, it is about 400 usd. The rest 8 you can connect using MB capabilities (sata ports +usb)
Than, using special technique , find layout (order, offset, stripe size, etc) or use external help via TeamViewer.
"Supemicro" raids is quite easy to reconstruct virtually, more problematic will be to solve logical issue with FS , seems rebuild made some destruction.

Re: RAID Recovery with 24 3TB drives

May 15th, 2017, 20:02

Instead of connecting all SATA drives, you can take a batch of drives, say 4 and make 4 images at the time. The load the images into a large RAID based DAS or NAS. Then work off the images.

Re: RAID Recovery with 24 3TB drives

May 16th, 2017, 3:58

The drives are 3TB and it's not easy tom image 24 x 3TB drives.

The only way to connect 24 drives is to use a and SATA/SAS Enclosure, but it that case it will impact the performances.

Any SAS/SATA controller that help me in my case?

Thanks

Re: RAID Recovery with 24 3TB drives

May 16th, 2017, 4:25

The correct answer has already been given to you.
DR-Kiev wrote:Buy Areca HBA controller (arc-1320-ix16) you can connect 16 sata hdd simultaneously, it is about 400 usd. The rest 8 you can connect using MB capabilities (sata ports +usb)
Than, using special technique , find layout (order, offset, stripe size, etc) or use external help via TeamViewer.
"Supemicro" raids is quite easy to reconstruct virtually, more problematic will be to solve logical issue with FS , seems rebuild made some destruction.

Re: RAID Recovery with 24 3TB drives

May 16th, 2017, 7:40

sosrecup wrote:The drives are 3TB and it's not easy tom image 24 x 3TB drives.

It is quite easy, just a bit time consuming. But it resolves your problem and you have backups.
And what I like about it is that there isn't a big headache trying to figure what is going on in case a drive loses connectivity (24 is quite a few), especially during file system rebuild/repair or file extraction process.
Plus it resolves the physical space being occupied with 24 drives around, etc.

Re: RAID Recovery with 24 3TB drives

May 16th, 2017, 9:23

If cloning the 24 drives to do a RAID recovery is too much work for you, then you should be referring your client to a lab who is both able and willing to follow best practices of cloning the drives before attempting recovery. Sometimes, if it is just better to outsource and get a commission/discount from someone who already has the resources.

Re: RAID Recovery with 24 3TB drives

May 18th, 2017, 11:03

In theory with 6 PC's you could connect 4 drives to each PC and then export all 24 as iSCSI target devices. In practice you could have a mix of SATA, drive image, and iSCSI devices.

You can identify out-of-sync drives by inspecting the raw drives and seeing where the "wall of zeros" begins. A drive that dropped out of the RAID weeks or months ago will hit the wall earlier as it contains less data. This can be automated.

If the client has a large file known to exist on the RAID you may be able to use it to deduce the drive order and chunk size.

Imaging all 24 drives would be a huge chore. Instead you could mark each drive read-only but slap on a small ramdisk to allow limited writes, for example this method allows you to safely try/test multiple RAID config settings.

If any of this sounds useful to you I am happy to help.

Re: RAID Recovery with 24 3TB drives

May 18th, 2017, 12:00

sosrecup wrote:....

His technician has regenerated the RAID (24 hours). then he couldn't see data.
....


Nice, nice....

16 ports SAS controller + PC standard ports will help you. Better to do physical copies, disk operations are faster than file opeations. After this Zen, deep Zen...

Re: RAID Recovery with 24 3TB drives

May 18th, 2017, 13:21

S.Haran wrote:In theory with 6 PC's you could connect 4 drives to each PC and then export all 24 as iSCSI target devices. In practice you could have a mix of SATA, drive image, and iSCSI devices...Imaging all 24 drives would be a huge chore.


How in the world do you think moving 72Tb of data across a network will be less of a chore than cloning 24 drives? Will probably take the rest of the year to complete doing it that way.

Re: RAID Recovery with 24 3TB drives

May 18th, 2017, 14:42

Yes it would be slow, hence the "In theory..." disclaimer.

Re: RAID Recovery with 24 3TB drives

May 18th, 2017, 15:08

S.Haran wrote:Yes it would be slow, hence the "In theory..." disclaimer.

When dealing with a client's data, "in theory" is not good enough.

Re: RAID Recovery with 24 3TB drives

May 18th, 2017, 15:24

While not itself a complete solution. It could be part of a solution to access all 24 drives. Plus it is non-destructive. So no harm trying. We do not know the full details of the case so having multiple options is a good thing. And let the OP choose the best course.
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