Mmmm.... 40+ years after going out of style as "Hopelessly Obsolete", Delay Lines return to the cutting edge.

Doubling lifespan that way requires that you only use half the disk capacity.

I have burned out a Major Name Brand SLC SSD with a high traffic OLTP DB in eight months. I have heard the same from Large Internet Companies which tested these for internal use. There are ongoing independent reliability expert studies in FAST, HOTDEP, other conferences which are uniformly highly skeptical of vendors' claims on SSD lifetime.

If you have not actually tested the drive out to six years service, run an accellerated pilot test unit out ahead of your main prod usage, to give you the canary warning.

I've tried to do large database server farm tests on modern enterprise SSDs with TRIM, the best wear load leveling, SLC, etc. They go "poof" at moderate (few months, for my loads) lifetimes.

IOPS x Lifetime / price is a metric I find useful. Unfortunately, it makes SSD look even worse than it does just on a price basis 8-(

Not really improved. I burned out a REALLY GOOD (best available) SLC SSD in 7 months with a mirrored production workload at a previous jobsite not that long ago.

Poof. All gone.

At the FAST conference, was yet another presentation on SSD lifetime burnout mechanisms, news not actually improving in the slightest so far on life. SLC is not good enough; MLC is toast in write-intensive apps.

Phase-change memory or one of the others, with millions of write cycles per bit, may pull this out, but Flash is not proving good enough for enterprises.

The Great Zero Challenge rules specifically exclude disassembly of the drive; all the bit-recovery mechanisms discussed in the literature require you to disassemble the drive and use custom heads to scan the surface magnetism map.

I.e., the contest is totally missing the point on what data recovery pros (i.e., the NSA and so forth) said they'd do if they had to scan disks to recover overwritten data.

It's hard to think of a less useful contest.

Oh? A plane with a single fuselage, fuselage front engine intakes, canards, a delta wing, resembles an aircraft with separate engine pods on a flat center section, underwing engine intakes, a V-tail?

There's nothing configurationally similar between those aircraft. Nothing.

There's a passing similarity with the FB-22 bomber proposal, but that didn't have canards, just a delta, and was never more than a paper proposal (no detailed design or prototype).

For what?

There is no US stealth fighter design with that size or characteristics.

Common fallacy - they bought a Soyuz and a lot of engineering time, and the vehicles are similar in configuration and concept, but the Chinese vehicles are essentially a whole new design and used nearly no Soyuz components other than the docking mechanism and imported space suits (I think that was it).

Looks similar doesn't mean design stolen from. Chinese engineers did most of the hard work on all of the hardware with those two noted exceptions.

The launch vehicle was all theirs.

There are plenty of tax havens to go off to and live in, if you feel that way.

Problem is, none of them are a large, expanding, dynamic economy.

They exist for a reason, but modern economics does as well - it works, and it wins out over time at producing the most benefit for the most people (including the rich, who at times object to how it works, but who are far far FAR richer in the west than elsewhere...).

The current system is not entirely fair or reasonable by any one group's definitions of those terms, and certainly sucks in many ways. Welcome to the Real World. It sucks, but obviously less so than any other ideas we've tried so far. See similar observations about western democracy as a government model.

When you have a model that you can adequately explain and defend as holistically better, you'll get converts. I have yet to see any critic who can explain an alternate model in detail, because most of the critics don't understand economies well enough to design and engineer one. So give it your best shot. Perhaps you have the cojones than all the professional issue radicals and far-stream economics professionals lack, new ideas and the brains to link them into a system and the communications skills to explain it. Go for it!

But not on /.

Prediction of really dynamic events - the long term weather, economics, etc - is really hard.

What you can do, scientifically, is analyze how different factors affect each other over time. You can predict that conditions are ripe for a type of event (inflation, unemployment spike, a market bubble, recession, etc). You can predict the course of an economic shift based on inputs (bailouts, government investment, policy changes, money supply changes, consumer confidence and employment, etc).

Being able to say "The bond market? It's going to collapse on Tuesday," is really hard.

Chastising economists because the economy is too complicated for us to do mid to long term projections accurately yet is unreasonable. They understand at micro, intermediate, macro, and international levels. They can show interactions and trends and make useful predictions. But they can't model the whole thing on an ongoing basis.

The Wikipedia article is intentionally not useful for designing anything.

However, we do have an online textbook (at roughly upper-division engineering/physics college student difficulty level) on the subject:
    http://www.nuclearweaponarchive.org/Nwfaq/Nfaq0.html

In terms of what's been published online -

* There's a book with precise dimensional drawings and measurements on the Little Boy type Uranium gun type bomb. Not online, but purchasable at Amazon. It's not "a blueprint" but any competent draftsman / mechanical engineer could produce blueprints to build from, given the book.

* The dimensions and materials of all the layers of the Fat Man / Mark 1 type nuclear weapons are published in numerous sources. The precise shape of the lens in the outer layer has not been, though a rough back-of-the-envelope version of the equation for the lens shape is published. A precise and buildable lens shape would require someone with a fair talent in explosives engineering and shockwave engineering, especially someone aware of what the published equation left out, but the Fat Man design is fundamentally so brick-solid-simple that one could get the lens fairly imprecise and still have a functional weapon.

Some effort has gone into not actively publishing newer weapon design details in public. But that's not nearly the same as "they're not out". A number of more modern weapons are understood to at least close to the level Fat Man and Little Boy are. There are accurate internal component photos declassified for some weapons and parts. There are detailed hands-on descriptions of some parts, by people who worked on them. Check out the Wikipedia article on the B61 bomb, for example; the fission and fusion components were shown in a declassified film (but not the explosives to compress the fission parts).

Not for nuclear weapon design information. That's "Restricted Data", see DOE classification rules. Accessed with a DOD TS-CNWDI (Top Secret - Critical Nuclear Wepon Design Information) or DOE Q-clearance plus appropriate Sigma compartment clearances for the specifics you're looking at.

No, it's not.

Differential backups are taking a single filesystem, seeing what changed (either at the file level (whole changed/updated/new files) or block level (changed blocks within files).

Block level deduplication is noticing that the storage appliance on which you back up 100 desktops and 10 servers has 50 copies of the same version of each data block in each Microsoft OS file from XP, 25 from Win 7, and 35 from Fedora, and only storing 1 copy of each of those blocks rather than 100 separate ones. It's returning those blocks to the usable storage pool and remapping without having to "compress" anything, not having to rewrite the backup data images, etc. It's just saying "This is block 3 of the binary for Internet Explorer 8, and I already have a copy of that", for each and every common block out there.

You still have to upload the blocks, and the system still needs to scan them to notice the duplication, but it's a lot more than "oh, compression".