SETUP RAID 0 on NF590

[morino]

I decided to raid two hard drives with nvraid on a nForce 590 board. Do anyone know where I can find step by step instructions on how to do this?

My manual is pretty scarce and have very basic instructions.

Also, why do Windows XP need RAID drivers during installation? I thought the chipset handles the RAID drives and makes it appear to the OS as one drive... and hence no driver needed.

 

[Captante]

First go into your motherboards BIOS & enable the RAID controller (if its not already), then when the NvRAID BIOS pops up during POST, press F10 & follow the directions... you'll use keyboard commands to select the drives to use & type of array to create, use the default cluster size & finally if you intend to run the OS from the array, be sure to make it bootable & exit the RAID BIOS saving changes by pressing Ctrl & x.

You will also need to have your motherboards RAID drivers on a floppy disk... they will be on the motherboards driver CD (hopefully with a utility to make the disk for you) or if you are lucky you will have gotten a pre-made disk with the motherboard. Boot from the XP CD & when setup fist loads, you'll need to press F6 to instruct XP to let you load drivers for setup from the floppy. (be sure to load BOTH the RAID driver & the IDE/SATA driver not just one or the other)

XP setup should then be able to see your hard-drives ... proceed to partition & format at you normally would & be sure to leave the floppy disk in the drive until setup is finished.

 

[morino]

Thanks, Captante. That helps clarifying the process.

Why do I need the floppy disk with the RAID drivers? I mean why wouldn't the RAID drives appear as one drive to Windows?

I assumed that the two drives in RAID would be transparent to Windows and the OS would see it as one drive. All RAID functionality should be handled by the chipset....

 

[Captante]

First you need the RAID drivers on a floppy disk because Windows doesn't have them on the install CD so it needs them to "see" your RAID array which you create in the BIOS in the steps I mentioned above... in many cases it needs a driver for SATA HD's in non-RAID configurations too & either way (as I mentioned above) it'll need both the IDE & the RAID drivers installed to complete setup. *(note that some new motherboards will accept RAID drivers off of a CDR or a flash drive, check your manual to be sure)

The second question is a two-part answer ... first there are two types of RAID controller, hardware & software based. Software is really more like "hardware assisted" because the chipset does lay out the parameters for the array, but all management of the array is done in software & processed by the main cpu both in & outside of Windows ... this is the type found on most consumer motherboards including the 590-SLI.

Second, pure hardware controllers still need the driver loaded at Windows setup in many cases, because Windows won't automatically recognize the controller itself & as a result also will not "see" the HD's, however the RAID array is controlled by a seperate processer with software management interface only. In these "true RAID" arrays performance & reliability are greatly increased but so is cost, with the least expensive decent PCI-card models coming in around the price level of a low-end enthusiest motherboard, while high external arrays can run $15,000 or even more.

 

[morino]

Captante,

Your explanations clear up some issues, but creates new questions about what I though was Software and Hardware RAID. Correct me if I'm wrong, but it seems like there are 3 types of RAID:

1. Purely software RAID, like Windows XP/2003 dynamic disk configured

2. Hybrid software/hardware (hardware assisted) RAID, often included on chipsets

3. True hardware RAID, like what is found on LSI Logic and Promise cards

I'm assuming difference in speed between "hardware assisted" and "true RAID" is barely noticeable if any for desktop/game computers.

So, with the drivers in place I will probably not "easily" be able to make an image of my RAID drives with Symantec GHOST...

 

[Captante]

Originally posted by: morino
Captante,

Your explanations clear up some issues, but creates new questions about what I though was Software and Hardware RAID. Correct me if I'm wrong, but it seems like there are 3 types of RAID:

1. Purely software RAID, like Windows XP/2003 dynamic disk configured

2. Hybrid software/hardware (hardware assisted) RAID, often included on chipsets

3. True hardware RAID, like what is found on LSI Logic and Promise cards

I'm assuming difference in speed between "hardware assisted" and "true RAID" is barely noticeable if any for desktop/game computers.

So, with the drivers in place I will probably not "easily" be able to make an image of my RAID drives with Symantec GHOST...

(1) I'd have to say I agree with you regarding the 3 levels of RAID technically, although dynamic disks can be setup on a single HD which would not be RAID regardless of how it was controlled.

(2) I've made a Ghost-image of a RAID 1 array running Win2k on an older Promise IDE RAID controller that had drivers included in Windows ... I simply restored the image to one drive & then rebuilt the array... its been quite awhile since I trusted any Symantec product though. I now use Acronis True Image Workstation with Universal restore which allows the installation of drivers for many different hardware configurations & have successfully restored a RAID 1 & RAID 0+1 array using it so far.

(3) The reason I referred to what most will call software-based RAID as "hardware-assisted" is that the array is configured by hardware, again all management of the array is done by the CPU & handeled either in the RAID BIOS which loads before the OS, or from within the OS itself, thus the OS crashing can much more easily corrupt an entire RAID 1 array for example. The performance difference between true hardware & "assisted" RAID can be slight or huge depending on the application, however all else being equal, the hardware controller will take load off the primary CPU and hardware will always cause less system overhead, as well as being far more reliable.


Edit: Note that both my main systems have 4 SATA HD's each... the first has 2 x 320gb & 2 x 500gb in 2 seperate RAID 1 arrays (This machine dual-boots XP Pro & Vista Ultimate) on an Asus Crosshair/Nvidia 590-SLI & the second has 4 x 160gb in RAID 0+1 on an Asus A8N-E/Nvidia NF4 Ultra. The reason I didn't bother with 0+1 on my newer rig was that the performance boost provided by the 0 part of the array was so small I didn't think it was worth it.

 

[morino]

I reason I used Ghost is because that is what I have laying around and do not use it enough to purchase a license.

Anyhow, I wonder if I can break the array (of RAID 0) and restore or image each disk individually. Then I would reconfigure the BIOS for the array again?

Otherwise I might have to look for an ASPI driver if they even exist for RAIDs.

Regarding (3), what I'm confused about is what does the OS need to control. For RAID 0, is it the splitting the data and determining where it will be laid out?

 

[Captante]

Originally posted by: morino
I reason I used Ghost is because that is what I have laying around and do not use it enough to purchase a license.

Anyhow, I wonder if I can break the array (of RAID 0) and restore or image each disk individually. Then I would reconfigure the BIOS for the array again?

Otherwise I might have to look for an ASPI driver if they even exist for RAIDs.

Regarding (3), what I'm confused about is what does the OS need to control. For RAID 0, is it the splitting the data and determining where it will be laid out?

(1) RAID 0+1 restored fine using Acronis with the Nvidia RAID & IDE drivers added, so I don't see why RAID 0 wouldn't restore using it... I don't know if Ghost will work because I'm not very familar with the latest versions.

(2) Yes, thats excatly what I mean.

 

[morino]

By the way I did a little search on my computer to find how many files were less than various striping sizes. Here are the results:

16KB -> 61397
32KB -> 70984
64KB -> 77817
All Files -> 91128

That is a surprising 67% of the files I currently have are less than the smallest striping size of 16KB. That is probably why RAID 0 does not help most people on performance. Instead of getting a double read the computer does a single read with probably some overhead due to the controller/OS. I do not know what the overhead time is, but I'm assuming seek time and overhead time will dominate most reads...

I wonder what the size of the max read (data fetch) is on the hard drive before it stores it into the cache?

Do you know how people optimize for performance on various striping sizes? It probably isn't worth it, but I'm curious.

 

[Captante]

I remember reading a test somwhere that compared the various cluster-sizes for performance (maybe on AT ... not sure) & I think it concluded that 32k works the best overall for the average home-system ... also its not that RAID 0 doesn't help at all, its that it doesn't help as much as it used to because drive technology has improved a lot.

 

[morino]

I think the article you are reffering to is:

http://www.anandtech.com/showdoc.aspx?i=2101&p=1

However, the article states that they used a 128KB stripe size. I'm not sure how a too small stripe size affects writes, but it would seem like the most optimized striping size is the same as the drives write/read fetch.

I think the conditions that RAID-0 is optimized is when

- striping size is less than most of the file being used (if not known, it should be as small as possible to to ensure most files are larger than the striping size, but not smaller than the conditions below)
- striping size is no less than the cache size of ONE read or write from or to hard drive

I can't believe that RAID-0 only gives 2-3% performance increase, given that hard drives are a factor of 1000 slower than CPUs...