Messages in this thread | | | From | Rob Landley <> | Subject | Re: what is our answer to ZFS? | Date | Mon, 21 Nov 2005 23:42:47 -0600 |
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On Monday 21 November 2005 14:02, Bernd Petrovitsch wrote: > On Mon, 2005-11-21 at 12:52 -0600, Rob Landley wrote: > [...] > > > couple decades from now. It's also proposing that data compression and > > checksumming are the filesystem's job. Hands up anybody who spots > > conflicting trends here already? Who thinks the 128 bit requirement came > > from marketing rather than the engineers? > > Without compressing you probably need 256 bits.
I assume this is sarcasm. Once again assuming you can someday manage to store 1 bit per electron, it would have a corresponding 2^256 protons*, which would weigh (in grams):
> print 2**256/(6.02*(10**23)) 1.92345663185e+53
Google for the weight of the earth: http://www.ecology.com/earth-at-a-glance/earth-at-a-glance-feature/ Earth's Weight (Mass): 5.972 sextillion (1,000 trillion) metric tons. Yeah, alright, mass... So that's 5.972*10^18 metric tons, and a metric ton is a million grams, so 5.972*10^24 grams...
Google for the mass of the sun says that's 2*10^33 grams. Still nowhere close.
Basically, as far as I can tell, any device capable of storing 2^256 bits would collapse into a black hole under its own weight.
By the way, 2^128/avogadro gives 5.65253101198e+14, or 565 million metric tons. For comparison, the empire state building: http://www.newyorktransportation.com/info/empirefact2.html Is 365,000 tons. (Probably not metric, but you get the idea.) Assuming I haven't screwed up the math, an object capable of storing anywhere near 2^128 bits (constructed as a single giant molecule) would probably be in the size ballpark of new york, london, or tokyo.
2^64 we may actually live to see the end of someday, but it's not guaranteed. 2^128 becoming relevant in our lifetimes is a touch unlikely.
Rob
* Yeah, I'm glossing over neutrons. I'm also glossing over the possibility of storing more than one bit per electron and other quauntum strangeness. I have no idea how you'd _build_ one of these suckers. Nobody does yet. They're working on it... - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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