Raid 5 failure

A collegue is asking me for help working with a server that has sensitive data on the Raid 5 array.  It will not boot for whatever reason (bad boot sector).  Tech onsite is attimate that we can't just swap one of the disks to see if that will enable the server to boot.

He is suggesting we make a bootable usb, then somehow transfer the data from the logical drive to the usb (it will be at least 1 tb) then we can migrate the data to another newer server.

Is this possible?  If so can you tell me how to do this?
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Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
Has the RAID 5 failed?

Is there a faulty disk?

If a single disk has failed your RAID5 should still function with a single disk failure

If two disks have failed then you will need to restore from backup.

This suggests some sort of disk RAID OS corruption
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
Any Windows LiveCDROM or Linux USB flash drive maybe be able to read the data
tike55Author Commented:
I have a spare SATA drive I can install on the server.  Should I just swap 1 disk at a time with it until the server boots? Would there be any harm (potential loss in data) in trying?

If there is a Raid Corruption, is all hope lost?  I'm not sure if there is a backup. :/

 is there any way to mount the logical drive to get the data?
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tike55Author Commented:
Would the Live CD or Linux flash drive just "see" the logical drive?
Tom CieslikIT EngineerCommented:
Or, you can install another disk with no Raid and install new OS on it. I think you don't need activate, but after install new Windows Server OS should have access to your RAID to copy Data over network or External Drive
tike55Author Commented:
My question is, the temporary OS will mount the logical drive?
tike55Author Commented:
when you say, "should have access" what exactly does that mean.  Does the logical drive show up in this computer as a drive?
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
If a disk has NOT failed in the RAID set swapping disks is not going to magically fix the OS Partition and Boot Files I'm afraid RAID 5 is working correctly if all working correctly.

Some file corruption has occurred which maybe on entire logical disk.

It's hardware providing the boot media has drivers that understand the storage controller you should be able to get at the files

A Windows OS media in repair mode will do this
tike55Author Commented:
so should we pop in a windows disk and try to repair OS?
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
And the drive will appear as a drive letter
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
Yes try repair
andyalderSaggar maker's framemakerCommented:
>Should I just swap 1 disk at a time with it until the server boots? Would there be any harm (potential loss in data) in trying?

Yes, there is great likelihood you will lose data if you do that. Assume one disk failed and another fell asleep, it may be able to reawaken the sleeping disk but not if you take it out of the server and replace it with a blank one.

First thing we need to know is what server / controller it is. Fortunately it sounds like whoever is on site has some idea of what they are doing, sounds like they plan to image each disk and try a software destriping tool.
Tom CieslikIT EngineerCommented:
Yes, if this is only Boot sector issue, and I think it is then you will be able to access raid from fresh OS.
You have nothing to loose.
tike55Author Commented:
I just got a few more details.  The motherboard was just replaced.    Should I be looking in the Bios?

My other question is there is sensitive data on the logical drive, if I pop a windows CD/repair, is there a possibility that I will further corrupt/delete/destroy the data on the array?
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
If you have NO BACKUP and the DATA is valuable

Get a specialist involved or Create a Live EE session Gig or Project to help you fix the server and or recover the data

Do not bungle a repair yourself and make mistakes and lose all the data
Tom CieslikIT EngineerCommented:
If Raid controller was on the motherboard, you have no configuration information about Raid now.
You must try rebuild Raid information using Controller Bios
Tom CieslikIT EngineerCommented:
Most of Raid controllers when see difference between Disk configuration saved on Disks and Controller Bios is asking what you want to do. I hope You or someone else did not select Overwrite disk data. If the did, you have no raid now and probably there is no way to recover anything from raid.
andyalderSaggar maker's framemakerCommented:
If the mobo has just been replaced maybe they just lost the controller write cache contents but it's certainlt too dangerous for us to just guess without even knowing the make of server.
You have some very good suggestions above and I'll add a different one.

I've used RAID Reconstructor from successfully on some RAID 5 arrays.  You connect the drives to a non-RAID controller and use it to sort out the particular arrangement (order of drives, stripe size, etc.) and then should be able to read data from the drive to copy to another drive.

As mentioned above, a RAID 5 array should continue to operate with a single drive failure, though it will be slower.  The issue may be greater than you think.  For example, there may have been one drive that failed altogether and then another that has has a partial failure.

Drive problems tend to get worse as the drive is run longer.  Keep that in mind as you try different approaches to retrieving the data.

I would second the comments above that you should NOT just randomly replace drives.  I would also suggest that your efforts should start with trying to recover the important data and not about getting the array to boot again.  Only after you have all of the data you need would I look at fixing the boot issue, if at all.
Olgierd UngehojerSenior Network AdministratorCommented:
I think that you have more than one hdd failed.  if you have hard raid you should see it in raid controller software, with softraid is much more to do to check what is going on. You can consider first to try do images of the hdd to safe data. There is some software what can transfer data - reimage it to virtual drives from raids. If you have more than one hdds with problem and imported data to recover I would not play with if you do not have experience. There is a few companies what can recover your data from broken raid hard drives but it can cost quite a bit.

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