Adding drives to a RAID

[vaughan]

Doomeva has a pair of Western Digital 74GB Raptors in a striped RAID 0 array. I am concerned that if something happens to either drive his PC will be stuffed.

Is it possible to add another pair of drives so he can have RAID 0 and RAID 1 without having to format everything and start again?

The motherboard is an ASUS A8N-SLI deluxe and it is supposed to be multi RAID compatible. My plan is to buy 2 more Raptors and run the RAID setup utility to create the mirror. Just want to make sure its going to work before I invest in the hardware.

[Jeff]

Hmm. Is the possibility for drive failure that high?

I'll do some research on dual raid and get back to ya


Jeff

[AMDave]

Should be good according to the PC Perspective - Asus A8N-SLI Deluxe nForce4 Motherboard review:
http://www.pcper.com/article.php?aid=98&type=expert&pid=17


...we see that Asus has stacked the A8N-SLI Deluxe quite well with a lot of storage options. How does eight SATA channels and two IDE channels sound? That should satiate just about anyone with a fetish for large hard drives. Only users upgrading from lots of IDE drives will have to look for new SATA hard drives. The NVIDIA SATA controller also supports the new SATA 3.0Gb/s standard, so when those drives become available you'll be ready. RAID support is very nice: NVIDIA's controller supports RAID 0, 1, 0+1 and JBOD that can span across both the SATA and PATA channels; the Silicon Image contoller supports RAID 0, 1, 10 and RAID 5. Did I mention the external SATA power and cable connectors Asus includes to allow for you to hot swap SATA drives without opening your case? SATA connectivity is king on this board.

You may want to check the rating on the PSU to make sure you can draw enough power when all 4 drives let fly at once. Any probs with the disk array should be resolved with a BIOS refresh. Check out your current BIOS version against the latest on the vendor's site.

[Empty_5oul]

not sure if this applies but i remember the original point of raiding it rather than having just 2 normal disks was for speed. (writing half to one and half to the other simultainously meant it takes less time).

If one disk died then the other was useless (the data on it anyway), as you only had 1/2 of everything. if you now add 2 more drives for backup (mirroring) it slows this down as the same data is written twice.

I dont know the speeds / timings but when i looked before it was much faster in certain appliactions to have striped raid, but i cant say i looked to carefully at mirrored.

I think the risk of failure is only as great as on a normal desktop machine, i can't see any reason why the risk would increase.

[NeoGen]

Aren't write operations on mirrored raids simoultaneous? I mean, isn't the "write order" issued to both sets at the same time, so making it simoultaneous, and the time it takes for one would be the same for both?
I can't find the right words to ask this question, but I think you can get the meaning.

[Empty_5oul]

this one is good:
http://www.3ware.com/products/pdf/RAID_Primer.pdf

says performance of mirrored striped is still good.

on here however http://www.technick.net/public/code/cp_dpage.php?aiocp_dp=guide_raid both 0 and 10 have "highest performance". so it sounds like you will be ok and not lose any speed.