On 09/01/2011 10:14, Patrick M. Hausen wrote: > I assume you are familiar with these papers? > > http://queue.acm.org/detail.cfm?id=1317403 > http://queue.acm.org/detail.cfm?id=1670144 > > Short version: as hard disk sizes increase to 2 TB and beyond while the URE > rate > stays in the order of 1 to 10^14 blocks read, the probability of encountering > an URE > during rebuild of a single parity RAID approaches 1.
Yes. Rotating magnetic media seems to be bumping up against some intrinsic performance/reliability limits to the year-on-year doubling of capacity. Having to add more and more "extra" drives to ensure the same level of reliability is not a wining proposition in the long term. Roll on solid state storage. I particularly like the sound of HP and Hynix's memristor technology. If memristors pan out, then they are going to replace both D-RAM and hard drives, and eventually replace transistors as the basic building block for electronic logic circuits. Five to ten years from now, hardware design is going to be very different, and the software that runs on it will have to be radically redesigned to match. Think what that means. * You don't have to *save* a file, ever. If it's in memory, it's in persistent storage. * The effect on RDBMS performance is going to be awesome -- none of that time consuming waiting for sync-to-disk. * A computer should be able to survive a power outage of a few seconds and carry on where it left off, without specially going into hibernation mode. * Similarly, "reboot" will be at the flick of a switch -- pretty much instant on. * Portables will look a lot more like iPads or other tablet devices, and will have battery lifetimes of several days. About the only significant difference is one will have a hinge down the middle and a built-in keyboard, while the other will only have the touch screen. Oh, and let's not forget the beneficial effects of *no moving parts* and *lower power consumption* on system reliability. Now all we need are the telcos to lay multi-Gb/s capacity fibre to every house and business, and things will start to get very interesting indeed. Cheers Matthew -- Dr Matthew J Seaman MA, D.Phil. 7 Priory Courtyard Flat 3 PGP: http://www.infracaninophile.co.uk/pgpkey Ramsgate JID: matt...@infracaninophile.co.uk Kent, CT11 9PW
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