RAID 300

Alright so I had another long night of doing linux admin work and after a long and ridiculous discussion with a colleague I came up with an insane idea that if I can pull off it would be hilariously awesome.

So I'm sure many of you are familiar with the notorious movie "300". The banter between my colleague and I somehow came across the subject of impractical raid configurations. Numbers were popping around in my head when 300 just came up out of nowhere. The more I thought about it the more I liked it despite being in general a dumb idea. My idea goes something like this:

4 RAID controllers that support RAID 3 with 3 drives apiece in their own containers(12 drives total). I'd use mdadm(linux software raid) on the next level to make two RAID 0 pairs with two sets of paired RAID 3 containers. At the top level I would string the two RAID 0 pairs together as a final RAID 0. This crazed concoction would form the RAID "300". The case housing all this would be decked out with references to the movie and thus I could claim to have a RAID "300".

Basically what I'm looking for here is ideas to improve the planning without breaking away from the "300" essence of a triple layer RAID. Any suggestions are welcome and I'll take any form of ridicule with stride considering how silly this idea is. I'm mainly looking for size suggestions, RAID configuration settings, controller recommendations, etc. Thanks in advance.

If there was any performace goal out of this, I'd think RAID-3 would be out of the question.

Here's an even dumber one...

2x EVGA SR-X mobos
13 Areca 1882ix-24 controllers
300 SSD drives

Knock yourself out.

That is pretty funny, but I see no practical use for it. That doesn't mean you shouldn't do it, however!

I've never had to look into it before, but does mdadm support RAID 3? It would be cheaper to set it up that way instead of trying to find outdated RAID controllers that still support that level.

RAID 500 would be a lot more practical, and faster too. You could still call it "300".

survient said:

At the top level I would string the two RAID 0 pairs together as a final RAID 0

Click to expand...

If you can tell me what you mean by this (as I think it might be a made up idea), then I'll agree that this is a great idea.

Why do you need 4 raid controllers? Get a 12port controller.....

I think they are doing it for fun.

You can stack RAID levels, even if they are the same. A RAID level of "00" would be multiple RAID 0 arrays put in a RAID 0. There really is no difference between that and RAID 0 of all the disks, except for block structure and complexity.

Yeah, I think I'm stuck with logical thoughts on this one, which makes me unhelpful.

You can stack RAID levels, even if they are the same. A RAID level of "00" would be multiple RAID 0 arrays put in a RAID 0. There really is no difference between that and RAID 0 of all the disks, except for block structure and complexity.

Click to expand...

Right. It's a strictly worse idea than striping them all together, but it does make it worthy of the "00" title. Just like RAID 3, which is strictly worse than RAID 5, but better for this project because it has a "3" in it.

Can't you do all of this in mdadm?

johan851 said:

Right. It's a strictly worse idea than striping them all together, but it does make it worthy of the "00" title. Just like RAID 3, which is strictly worse than RAID 5, but better for this project because it has a "3" in it.

Can't you do all of this in mdadm?

Click to expand...

yeah you can, but I've never done it. Therefore, it must not be possible. lol

RAID 3 has a bit more involvement than RAID 5(supposedly), thus it is only supported at the hardware level, and mdadm doesn't support it. This theory may hold water as RAID 3 needs the spindles in each of the drives to be synchronized to work. There are relatively inexpensive hardware RAID controllers that support RAID 3 but don't have 12 ports, thus the need for 4 of them. RAID 3 reportedly is still in use in some proprietary hardware implementations for large file transfer related applications such as raw video editing and livestreaming(if you have extremely high quality I'd think), due to it's "high throughput". Even if this is the case, I think most of the performance will be lost due to the nested layers of RAID 0. We'll see though, I'll get a bunch of drives and run some comparative benchmarks in various configurations before I finalize the RAID 300.

I know the Taiwan flood fiasco raised drive prices, but anybody see a good deal on 500 - 1TB drives lately? Since I'm doing this "on the cheap" I'll probably use these controllers:

http://www.newegg.com/Product/Product.aspx?Item=N82E16816124043

They don't literally spin the spindles in sync, that would be impossible. They run in lockstep, which is totally different.

This should be do-able in software.