Non disk storage?
The key problem with virtual systems like the ones we run here is that the disk drives create a bottleneck. I think that one of the main reasons that linode is so much better than many other VPS providers is that we have the IO token system that prevents one user from choking off other users.
Wouldn't a better solution be some sort of solid state storage system that didn't have that mechanical disk performance bottleneck?
Linode has been beefing up our storage. I can't even remember where it was when I started here -- I think I had 2GB. Now it's 10G. I didn't even know that until I checked -- I'm only using 8G
But really, I'd rather have 2GB without the need for the tokens. 10G is great, but 2G was good enough.
I know that Intel pays Jeff Dike to work on UML. Does anyone know if they're working on any kind of a hardware solution for the storage bottleneck problem?
I mean, the software works pretty well now. I don't think we're limited much by the software. The real problem is on the hardware side.
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500Gb disk, (Seagate Barracuda SATA II) $145, or $0.29/Gb
32Gb Solid state (Samsung, IDE), $400, or $12.50/Gb.
Thus, SSD is 43x the cost/Gb. You can probably find other examples that would tweak that number a little, but not enough to make it feasible. Not to mention that each server would need a bunch more interfaces to support the same amount of disk space.
The other problems you mentioned are more serious – how would you plug them all in?
I guess my question is -- what would solid state storage look like if it was designed for a place like linode?
Would you want a different kind of controller than we're using now? Does it make sense to wrap a flash drive in circuitry that makes it compatible with controllers designed for magnetic disks?
Let's say I took a 6G usb flash drive and plugged it into my PC, and ran 3 2G virtual systems off of it -- would that even perform better than three systems on a magnetic disk? The flash drive is a lot slower than my magnetic drives.
I don't know that a solution is available off of the shelf. But I'll bet someone could build one if they made raw speed and parallel performance their goals.
Terabyte SSD disk array. Cost a million bucks in 2003. Not sure how much now.
> I know the cost is a problem. But if you can't accept the magnetic disk bottleneck, and you don't need massive quantities of space, maybe it's acceptable.
Given the premium of SSD, if you're worried about I/O bandwidth then you might be better off getting a real colocated server, rather than a virtual server. That way you're not sharing with anyone.