Best way to setup a raid array?

[Pob255]

I've got 4 enterprise class 80gb hard drives I'm planning to put them into a raid5 array for a fresh install of win7 pro 64bit.

But I've not done this before and I'm wondering what the best method for doing it is?

Motherboard is my Asus M5A990x amd 990x chipset.

Now I can set sata ports 1-4 into raid mode in the bios, while leaving ports 5-6 and the additional 2 sataIII ports in AHCI mode (or even ide)

Do I just need to do the BIOS setup then create the array in the AMD option Rom utility then continue as normal? or is it done as part of the dvd OS install?

[1stRaven]

Its done before the OS install. Once you switch the sata ports across to raid mode, you should see a raid bios option (I'm going off experience with Dell and Intel raid chips) which you enter into (like a standard bios) and configure the raid array there. Once done, save the config, reboot and boot in the OS setup.

Win 7 disc should already have the drivers if its a standard raid chip and so, be able to see the drive and then you can partition the drive as you would normally. If the drive doesn't appear, load the raid drivers into a usb key, put then into your machine and then install them from the OS install at the disc menu (the point where you select which disc to install the os too).

Hope that helps.

[smargh]

I don't know of any 80GB enterprise drives... do you mean 72GB?

Using onboard ports for RAID, rather than a hardware controller card, will only result in pain and anguish.

[shaithis]

Yup, your array needs to be setup before installing the OS. Once an array has been setup it is seen by the computer as "a hard drive". You can then partition it if required during the OS install.

Personally, I am not fond of RAID5 write speeds and tend to only use RAID 5 in certain situations.....I would seriously consider using RAID10 (if your RAID controller supports it) for an OS install.....you will lose half of your capacity but performance will be better on the whole.......or if you trust your backup regime, go RAID0!

[peterb]

The real question is why?

RAID is not a substitute for backup, performance (using an onboard controller is unlikely to be better (and probably worse) than using the drives normally, and if you want to aggregate the drive sizes, using logical volumes would probably be a better route to take.

Whichever route you take, don't neglect backing up.

[Biscuit]

Might be worth pointing out the different kinds of RAID before i explain what to do:

Software RAID: This is done in the OS, it is handled differently by different OSes so the capabilities are hard to pin down exactly however the control and processing will be handled by your CPU. Whilst in Linux software RAID is quite flexible (I have played around with MDADM), as far as I know, in windows you cannot create a software RAID5 array and boot from it, feel free to correct me! Small performance gains might be noticed.

Hardware RAID: Done using a dedicated hardware card, the advantages here are that as long as the drives and card are kept together, you can move the array about to different machines without problem and all the processing is lifted from your CPU. The downside is that there might not be boot drivers so your OS may not install to a the device. You are likely to see fairly large performance increases with a decent controller card.

Fake RAID/Host RAID: This is what most people use (myself included) and it is actually technically the worst of both worlds. Not only is the processing and control put onto the CPU in your system but you are dependent on that motherboard for the array assembly data AND You can encounter boot driver issues with OSes. Unfortunately I think in windows this is the only cost effective method of achieving what you want. Small performance gains might be noticed.

Now for some guidance.

• Download the drivers from the Asus website for your RAID controller. If there is loads of different ones, just grab them all and stick them on a USB drive.
• Boot into BIOS and set the SATA port settings so that you have RAID control of the ones you need
• When you boot up the next time, after BIOS you will get an additional screen which will ask you to hit a key to enter RAID setup (usually f9)
• Once in the RAID setup go through the motions to getting it set up, this can sometimes be a bit confusing but I'm sure you will figure it out. Make a note of the name you give the array
• Boot back up into BIOS and check your boot disk priority. You should see the name you gave to the array in the list, set it as primary.
• Put your USB drive with the drivers on it into your PC and boot into windows setup. Go through normally, if windows doesn’t find the drivers for the array controller then try and it amongst the ones on your pendrive
• Continue as normal, Just remember your reliant on both windows and the motherboard now so make fairly regular backups of your system drive!

[Pob255]

The real question is why?

RAID is not a substitute for backup, performance (using an onboard controller is unlikely to be better (and probably worse) than using the drives normally, and if you want to aggregate the drive sizes, using logical volumes would probably be a better route to take.

Whichever route you take, don't neglect backing up.

Ok to answer these point.

Because I can.

I know it's not a substitute for backup, it's simply that I got these drives free
They where pulled out of a low cost server (along with the nice 7 disk hotswap bay which I plan to mod into a case ), which was only used for about 4 months and was going to be scrapped
(it was part of a trial for some software that was pretty much universally hated that the developers ended up canning it and starting again.)
When I spotted the fact that it used SATA drives not SCSI or SAS. (I have to double check but I think I got it wrong, I think they are 160gb RE which where basically caviar SE with thicker aluminium casings)

I've not messed around with RAID before so I was thinking of giving it a go as it'll cost me nothing.
And it'll be a nice way to make use of a bunch of 80gb disks.

I didn't think motherboard raid was that bad I do want to get a raid card as some point, mainly for multiple HDD activity led's.

I'll have an experiment and potter at the weekend and let you know how I find it.

[Biscuit]

In practice, motherboard RAID isn't that bad. Most of the time the drivers are easily available and work perfectly fine, processing is no longer really an issue given the power available to modern systems and how often do you change your motherboard? Every couple of years at best for most people and by which time its probably a good time to start with a fresh windows build anyway.
I use it despite what i have posted above and i have a spare Dell PERC5i (which is a pretty damn good RAID card) sitting around doing nothing. It’s a pretty convenient solution and it does, in most cases, offer some performance increase over a single drive. It will depend a lot on the drives used but have a look at this:

http://www.overclockersclub.com/revi...xt_500gb/4.htm

I used this example as I am using 2 x 320GB Momentus XT drives in a 'Fake RAID0' setup myself. As you can see there are some instances you will receive a 50% increase in speed but some instances where the speed is actually hindered by the RAID controller. The main issue people may have is that if you set off 2 x synchronous data transfers, one to each disk, the overall speed would wipe the floor with the fake RAID, obviously that’s great for storage disks but useless if you are using it as a boot disk.

[shaithis]

A lot of the performance issues with software/firmware RAID is that there is no dedicated cache RAM on the board. Controller cache significantly effects performance.

[peterb]

Ok to answer these point.

Because I can.

<---snip--->

I'll have an experiment and potter at the weekend and let you know how I find it.

And that is a perfectly valid reason! In fact it is a very good reason, because with your history/experience in building and modding, experimentation and the resulting increase in knowledge is a very good reason for doing it!

Too often people come on asking about RAID in the belief that it will sort out their backup problems/give stella disk performance/make their tea/do the ironing!

So good luck with it and let us know how it goes!

[Pob255]

do the ironing!

Now that's one I will have to test!

[kwai]

hmm on my asus m4a79 deluxe
when you turn on raid on the sata ports, then reboot the machine, after the bios post has gone, the AMD raid controller screen shows up, then you press an F button to go into setting up your raid array.
note that when installing windows (7 or vista), you need to have the raid driver on a usb stick or something like that, otherwise the windows installation wont detect the array.

another note raid 5 is slow,
raid 10 is probably the best solution for redundency,
i'm using raid 0 on 2 x 320GB disks, its ok been running for about 2 years no issues so far *fingers crossed* , but i think next time i will just buy one really big hard disk, and a spare for backup.

[dave87]

Pob - you've got five drives haven't you?

If so, I'd be tempted to do 2 drives in RAID 0 and 3 in RAID 5. More useable space - gives performance for the OS drive perhaps, and a bit of resilience for other, less replaceable files?

As others have said, it is no substitute for backup but that would be how I'd set them up...