Date: Wed, 21 Feb 2007 08:58:14 +0100 From: Wilko Bulte <wb@freebie.xs4all.nl> To: Matthew Seaman <m.seaman@infracaninophile.co.uk> Cc: freebsd-stable@freebsd.org, Alan Amesbury <amesbury@umn.edu>, Ivan Voras <ivoras@fer.hr> Subject: Re: getting garbage faster using FreeBSD? Message-ID: <20070221075814.GC53528@freebie.xs4all.nl> In-Reply-To: <45DBF4D1.6000708@infracaninophile.co.uk> References: <20070220215248.3C22216D23E@hub.freebsd.org> <45DB8B8D.6080706@umn.edu> <45DBF4D1.6000708@infracaninophile.co.uk>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Feb 21, 2007 at 07:29:21AM +0000, Matthew Seaman wrote.. > Alan Amesbury wrote: > > Ivan Voras wrote: > > > >> The obvious question - why don't you burn the tapes and hammer the disks? :) > > > > Ah, low-tech. I know it well. Still, the last time I did any data > > destruction, I found a 4 Tesla magnet does wonders. Downsides: > > > > 1) Oxford's 90cm bore, helium-cooled magnets aren't that > > common, perhaps because a 2000V/500A power source > > is a bit expensive (solution doesn't scale). > > It ain't the PSU that's the expensive bit on a supercon magnet -- it's the > liquid Helium. After all, once you've ramped the current in the coil up to > $bignum amps, it just keeps going so long as the superconductors aren't > allowed to heat up. LHe costs about the same as good whiskey, and you need > gallons of the stuff every few weeks. > > > 2) The hard drive has a tendency to fly out of one's > > hands while moving it through the lines of force > > (solution requires some physical coordination). > > Hmmm.... a solenoid coil magnet has a field that is approximately dipolar. > Forces vary as the inverse *cube* of the distance away from the center of > the magnet. Move a centimeter too close and the drive will suddenly be > ripped out of your hands harder than you can resist. Sounds like what the military are experimenting with: magnetic rail gun. > > It's primarily for item #1 that I hadn't mentioned this earlier, as most > > readers of -STABLE users are probably looking for a more scalable solution. I once had business with a customer from the military who wanted to permanently decommision some disks. I proposed a main battle tank. And, apparantly they saw the fun in that, they reported back that gently rolling one over a disk indeed does the trick nicely. So when you do not want your living room spoiled by a 4T magnet go and find a surplus Challenger tank (when in the UK) or a M1A1 Abrams (when in the US). Plasma torches like found in car body repair shops also do it just fine. -- Wilko Bulte wilko@FreeBSD.org
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20070221075814.GC53528>