RAID for Zero-G?

Cujo asks: "In all seriousness, I need a RAID that supports at least level 3 and stores > 500 GB, and I need to it work in zero-G (but not in a vacuum), and be able to take a fair bit of vibration and noise when turned off. I don't want to spend huge sums: I'm thinking well less than $50,000. I've looked at Apple's XServe/XRaid products, and they look great (about $10,000), but are they rugged enough and who is their competition? Some people make hardened RAIDs for military use, but I'm unfamiliar with the best candidates in that field (and do I really need mil spec?)."

Re:I don't have an answer, but...

[mcelrath]

With the drives off and parked I'd think that any drive would work. Zero g shouldn't be a problem since any drive I've seen can work upside-down or on its side.

The shock tolerances for the drive should be available on the technical data sheets, and I'm guessing that for off-and-parked it's in the 100's of g's or more. You probably want to consider building a custom RAID mount for it with lots of rubber grommets. I know here at WI some of our rocket guys have vibration mounts whose sole purpose is to shake the shit out of electronics and make sure it survives. Glue in and zip-tie all the connectors. All in all, it shouldn't require an engineering miracle to survive launch...

And hey, what's your experiment? :)

-- Bob

Re:Heat and Perfformance

[spencerogden]

It would seem to me that you would want max reliability on the flight, and max performance on earth. Is the few hours it would take to transfer >500GBs bad enough to preclude copying to a higher performance system upon return. (Assuming the most reliable and fatest solutions turn out to be utually exclusive)

As a side note: If you are sending an experiment up on the shuttle, aren't there resources at NASA you can check with? Surely someone has sent a hard drive into space before. As someone mentioned, The only moving parts would be in the drives, so everything else is probably more robust than the drives, they are the weak link you need to worry about.

Re:Have you tried IBM?

[jafuser]

This is actually a good point.

An array of the model of hard drives normally used in a laptop would probably be ideal since it is most likely designed to:

• withstand greater accelerations (laptops get banged around a lot more than desktops/servers)
• use less power (since laptops run on batteries)
• have a smaller size
• create less heat

I'd suggest doing some research to gather the model number of hard drives used in some of the high-end laptops and then go from there.

Cost Per Pound Issue?

[4of12]

I've heard it costs about US$10K per pound to put an object into orbit.

If that's true, why isn't weight more of a consideration?

I presume your project's individual cost limit is preventing you from investigating solid state disk solutions, which would probably be less susceptible to shock than platters in a magnetic disk hard drive.

Re:Zero-G likely matters not

[linuxwrangler]

The vibration is more of an issue; however, if the drives are parked.. it shouldn't matter too much..

Maybe not to the drives but the whole system must be considered. Drives don't work well when the power or data cables shake off or the raid board or CPU on the system comes loose. Machines exist to shake 'n' bake equipment (NASA or its contractors will have them). I wouldn't send up an experiment unless it passes a ground simulation of the vibration, G-loads, temperature, etc. that it will experience on liftoff, reentry and orbit.