nvidia nforce 430 raid setup

[dheinle]

Has anybody used the nforce raid setup? How well does it work, can I expand from 3 to 4 drives if using raid 5?

1 of my boxes has the nforce chipset and I was looking at using it for my new server and run 4 x 1.5tb drives in raid 5. If I could get a way with 3 drives and add a 4th later that would be great. if not i'll just start with 4 drives.

Can this chipset handle 3 HD OTA and 2 analog streams recording to raid 5 at once?

Thanks
Dennis

[vexhold]

You should have no problems starting off with three and adding a fourth.

On a side note:

In a RAID5 array each drive is written to sequentially according to the block size of the array, with a parity block included for redundancy. Each read of a file depending on size, is read from every disk in the array. ie. the first part of the file brought off disk 1, the second part of the file off disk 2 etc. until the file is read in its entirety.

In a 3 disk array you can have 3 simultaneous reads one from each disk piecing together the file. A 4 disk array you can have 4 simultaneous reads. So increasing the number of disks should theoretically increase read speed as with each disk you add another simultaneous read is available, although adding more and more disks creates more overhead. Now we can see that if we have a dedicated controller card(with its own processor and ram) rather than an onboard controller (using other machine resources) that this overhead may overcome the capabilities of the onboard controller faster than a dedicated controller. Obviously it still directly relates to how fast the controllers are, but dedicated hardware will always decrease overhead on a system.

If in a 3 disk array we have 3 drives whose interface support 300Mb/s (SATAII theoretical) each drive should read and write data at the same speed. Therefore, each block from each drive will be read in about the same time and be available. However, if we take a 3 drive array with 2 drives at SATAII and one at SATAI (150Mb/s) we come into an issue where drives one and two should theoretically read 2 blocks per 1 block on the third drive. This is where the drive with the slowest speed in the array slows the array down. If we need 6 blocks to piece the file, 2 blocks on each of the 3 drives then drives one and two are going to complete reading of there 2 blocks while the third is still reading the final block stored on it before the file can be recalled. Therefore any sequential reads or writes on the array would be slowed down by the read/write speed of the slowest disk


So using four drives would be an increase of read speed. Just something else to think about when making your decision.

[dheinle]

ah yes, more spindles = more speed.

since the 1.5tb drives are only $120 at newegg today I think I might just order 4 and be done with it. That should give me enough storage for a long time.

Dennis

[stanger89]

Originally Posted by vexhold

You should have no problems starting off with three and adding a fourth.

Don't be so sure, most onboard RAID does not support online capacity expansion.