mounting degraded RAID 5 from hardware raid into softare raid

staffmm · #1 22nd October 2009, 12:41 PM

Hi Everyone,

We have a RAID array on a windozes server (I know, i'm sorry), and its hardware RAID.

Now, yesterday, we came in and were welcomed by a big blue STOP screen. fun.

So we had a look, and it appears that two of the hard drives have failed :S. They are two unstable to boot from, and i have been asked to create imgs of them, for while i'm working on them, to prevent any further damage being done to the actual disks.

So i was thinking, maybe i could do a dd copy of all three hard drives, whilst not in the array (so clone zilla drive to partition), drop the data into 3 partitions within imgs, then mount the imgs as dev/sde dev/sdf dev/sdg.

Add them to a software RAID array, without re-formatting them, so the software RAID simply picks up the degraded raid, and treats it as RAID 5, and i can access dev/md0 and pull all the data off.

What does everyone think? Would that work? Have i missed something? Or should i just shutup and stop making a fool of myself?

I've been looking @ http://www.linuxhomenetworking.com/w..._Software_RAID and was wondering if i could perhaps ammend that to my needs?

I'm afraid i don't have alot of experience with the linux terminal, well atleast to this degree. So if someone with the knowhow, would indicate which commands i should use, possibly out of the linked page, i'd be extremely greatful.

I've been playing around with Palimpsest in ubuntu (because i couldn't get fedora live usb to boot :S), but i was worried, because, firstly, it seems to think that it only needs two out of the three hard drives, to have a RAID 5 stable array, which is amazing if it can, lol, but i'm guessing its just buggy, and secondly, when i added three blank hard drives, it said it was recovering them, or possibly it meant initialising them. But obviously the last thing i want the RAID array to do is initialise my disks!!!

I want to use the current array thats on them, and just port it from a hardware controlled array, to a software controlled array. I don't want to initialise my disks!

I'd be very greatful for any support that can be given, even if its just a command that i can look into.

TIA,

Matthew Millar

staffmm · #2 22nd October 2009, 10:46 PM

OK, i think i've worked out alot of the problem, theres just one bit i'm stuck on.

How do i mount create an array with three partitions, without reformatting them.

I.E. mount the current raid array thats on the three partitions?

Thanks,

Matthew Millar