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I have a PC that refuses to boot. I have 4 disk drives on a RAID array (RAID 0, or possibly 1), that is provided by my motherboard. I have 1 primary HD, and an extra 4 for the RAID.

I want to recover some of the data on the RAID array if possible. If I buy a completely new machine and plugin the 4 disks to another RAID array will the new computer be able to read these disks, or will I have to make sure that I purchase the same motherboard that I have currently (An Abit QuadGT)?

I don't want to purchase the same board if possible, as I wish to move to an I7 based PC. But if I have to, then I will buy a 2nd hand QuadGT if I can get my hands on one.

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I want additional information. Specifically, has anyone been able to migrate RAID from one motherboard to a second motherboard (whether working or not)? I'm looking at this from a perspective of being about to setup fakeraid using an ASUS motherboard that uses the AMD SB850 controller. Basically, I see the challenge of fakeraid compatibility between manufacturers. However, if your purchase your new motherboard from the same manufacturer, can (or has anyone) you get your data visible/usable? Bounty given to answers directed to these questions. –  Rolnik Nov 25 '10 at 20:19
    
I think you've somewhat hijacked the question there :P. Anyway from personal experience as novice linux user, I failed at porting my raid5 array, and ended up recreating it. In my case two manufacturers with the same controller weren't compatible. –  RJFalconer Nov 25 '10 at 20:49
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See much longer answer below. On Windows I've move a 2-disk RAID 1 mirror - twice. Between Operating Systems and between 2 different motherboards. With no data loss. The mobo shift was from an ASUS P5B to an ASUS P7F-X. If you do this I do suggest you back it up first! –  quickly_now Nov 25 '10 at 23:37
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3 Answers

up vote 3 down vote accepted

If the array is a set of mirrors, they may work on another controller. That chance is considerably smaller if it contains a striped set (RAID 0).

In general, though, this is why "fakeraid"/motherboard raid is a bad idea. There's a good chance you'll need that exact RAID controller, or a similar one, to get access to the volumes. True hardware RAID would allow you to transfer the controller, and software RAID would keep the array portable as long as you used the same OS (at a small performance loss, although not much of a big deal these days).

Also, a good illustration of why RAID is for redundancy (or speed in the case of 0), not backup.

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Thanks, I agree about the motherboard RAID being a bad idea, unfortunately I learnt the hard way! –  Richard Dino Nov 8 '10 at 21:01
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This is one of those topics that tend to polarise opinions (especially by those who have not thought about this issue a bit).

S/W RAID (as implemented in Windows, Linux, etc) means you not dependent on the peculiarities of the hardware RAID controller. It is also a tiny bit slower in performance than H/W RAID.

H/W RAID means that your OS needs nothing clever or special - it does not even know its talking to a RAID volume (or at least, in principle).

H/W RAID generally means, though, that you need the exact same RAID controller in order to recover anything.

In any system like this you need to analyse the weak points: the single points of failure. For example, a drive might fail, and if you use striping then you lose the lot. If you use mirroring (or RAID 5, or a combo like RAID 1+0) then you don't. If you lose a h/w RAID controller, you need another one the same to be sure of getting stuff back (potentially you can lose the lot). If you lose a processor or RAM then you need replacements, or some means of getting the controller or drives on new hardware (or you lose the lot).

Each of these has associated risks and ease of replacement if the broken item.

As pointed out before, RAID is not a substitute for backup. Understanding all that, if you want to reduce your exposure to single point failure events, then the smallest amount of hardware "stuff" is probably the better way to go, which means, s/w RAID done by the OS and wear the performance hit.


This then means that in your case, that if you can get the exact same H/W RAID controller your chances of getting the data off are improved (but not 100% - depends on what went wrong). If you can't get the same controller, the chances go down. Possibly to zero. You won't know until you try, but don't go betting money on the outcome.

If you buy the exact same m/b, and plug all the drives in, you may get somewhere. You may not. You say the machine won't boot, and the cause of that might be that the boot disk / sector / information / partition has been hosed. If thats the case it does not matter what h/w you try and use, your chances are not good.

If the cause is the raid controller being broken you may get somewhere. It's all dependent on what caused it to break.


In the case of Rolniks question: My experiences with h/w RAID have been generally unhappy either in the setup or the long term outcome (I've seen many h/w RAID 5 systems that suffer a 1 disk failure and can't recover when they should - thats what its for!). I've used a number of s/w RAID systems (Solaris and Windows) and had no troubles at all with rebuilds, recovery, etc.

I've also picked up a 2-drive mirror from Windows, and migrated it from XP to Win 7 on the same box with no data loss. And then plugged it straight into completely new hardware and had it all "just work". Again no data loss.

For me, everything to do with S/W RAID has been a winner. (Also means just pick a mobo with lots of plain ole SATA ports on, and plug in drives... easy and cheap to set up).

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Nice answer @quickly_now . You cover my core questions, as well as related issues (RAID <> backup). You identify that if the error lies in the data of the RAID itself being corrupted, then all bets are off. But you give hope that if its merely the mobo that died, then possibly the same manufacture may have an 'upgrade' path for the RAID. –  Rolnik Dec 1 '10 at 18:57
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I see little reason to set up a fakeraid system when you could set up an equivalent software-raid system in a linux distribution that would be readable by windows. As it's hardware agnostic, it would be relatively easy to recover should something go wrong.

That said, setting up mdadm for such a situation would be a lot harder than just using fakeraid and hoping your linux distribution gets round to supporting the motherboard-specific implementation. (I failed at finding a comprehensive mdadm guide for windows-readable software raid, although I know that it's possible)

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