Two RAID-arrays?

[dzidzius]

Hi,

I'm about to buy two new harddrives and put them into a RAID-array. Now, I have a array with two 160GB IDE-drives. My RAID-card have two unused SATA connections and thats why i'm about to buy two SATA-drives. The question is if it'll work with two different arrays. Here what I meen:

C:\ - 200GB drive
E:\ - 2x 160GB IDE
?:\ - 2x 250GB SATA

Is that going to work??:confused: My raid-card: http://www.promise.com/product/product_detail_eng.asp?segment=RAID%20HBAs&product_id=107

[catsarecute]

it works well for me i have 2*250gb and 2*36 on my onboard controller(dfi ut ultra d)(i dont get the speed i should getting but it works) good luck!

[dzidzius]

Anybody else that have the same experience that catsarecute??

[Reinvented]

2x 74GB Raptors RAID 0, 2x WD Caviar SE 16 250GB - RAID 1 NVRaid controller.

[mtl_hed]

Certainly possible, but that cards specs don't list if it supports multiple arrays. Some cards will only do 1 array, but since that has both IDE and SATA I would imagine it can do at least 2 arrays.

Are you intending on running RAID 0 or 1? B/c if you are going to run 2 RAID 0 arrays, you will hit the throughput of the PCI bus very quickly.

You have a maximum theoretical throughput of 133MB/s.

Just for reference, my setup:
2x120GB in RAID0 On southbridge
2x250GB in RAID0 On Silicon Image 3114 controller

[uOpt]

You have a maximum theoretical throughput of 133MB/s.


No, his NVidia SATA ports are in the southbridge and not subject to PCI bus limitations. I personally got 180 MB/sec out of these ports with just three Seagate 7200.8.

The Silicon Image chip junk is on the PCI bus running at 32bit/33MHz, but that doesn't matter since the chip isn't capable of using anywhere close to 100 MB/sec even with enough drives.

[dzidzius]

I'm running a RAID 1 array atm. What is the difference between RAID 0 and 1, and which of them should I choose relating to my actual array?

[Serra]

I'm running a RAID 1 array atm. What is the difference between RAID 0 and 1, and which of them should I choose relating to my actual array?

Whether you should use 0 or 1 depends on whether you want speed or fault tolerance.

With RAID 0 (disk striping) your data is spread accross multiple disks. Let me give you an example. Lets say you have 32kb of data that's being put on your hard disk. Lets also say for the sake of convenience that you've set it up such that your stripe size is 16kb. What will effectively happen is that the first 16kb will be written to your first disk, while at the same time the last 16kb is written to the second disk. If you had 64kb of data instead, the first hard drive would get the first and third 16kb's, and the second the second and fourth. With me so far? Because of this, you theoretically cut your disk read and write times in half (though real world performance is less than that). The down side of this is that if one disk fails, you lose all of your information because you can't reassemble any of it.

With RAID 1 (disk mirroring) you essentially just take your data and simultaneously write the same data to both hard drives. As a result you can have a disk fail, but you'll be giving up 50% of your total storage capacity for that ability, as well as paying extra for the mirrored hard drive.

Hope that answers your question.

[mtl_hed]

I'm running a RAID 1 array atm. What is the difference between RAID 0 and 1, and which of them should I choose relating to my actual array?


Wiki has a good write-up of RAID levels if your in for a read: http://en.wikipedia.org/wiki/Redundant_array_of_independent_disks

[mtl_hed]

No, his NVidia SATA ports are in the southbridge and not subject to PCI bus limitations.

He's not using the nVidia ports. Read the original post:
My raid-card: http://www.promise.com/product/produ...product_id=107

Hence the 133MB/s limitation.

[dzidzius]

With RAID 1 (disk mirroring) you essentially just take your data and simultaneously write the same data to both hard drives. As a result you can have a disk fail, but you'll be giving up 50% of your total storage capacity for that ability, as well as paying extra for the mirrored hard drive.

Hope that answers your question.

So that means that if a make an array of two 250GB hdds with RAID1, I'll just get 250GB of storage?

[Reinvented]

yes.....

[uOpt]

He's not using the nVidia ports. Read the original post:


Hence the 133MB/s limitation.

Urgs. :(

Yessus.

Obviously he'd be muchy better off running software raid (not sata controller onboard raid) with the nvidia ports.