(I still do things the classic way: filesystem on lvm on luks on mdadm. not using ZFS yet.) I'm not sure it's exactly about what's required.

Consider wear leveling on SSDs. Only the filesystem really understands which blocks need to preserve data and which ones are don't-care. So to do SSDs right, it needs to pass info about unallocated storage down to the volume manager, whch then passes it to the encryption, which then passes it to the RAID, which then gives it to old-school "real" block device (which then passes it to the wear-leveling firmware, I guess). Sure, that can work. But when the filesystem can talk to the physical block device, it's easier. If you're writing block devices that implement things like volumes and encryption and RAID, from your PoV, things that are allocated vs not-allocated are totally different than how the filesystem sees it. To you, a block is just a block and a whole bunch of ioctls are totally irrelevant and not related to what you're working on. You're going to find this type of information to be pesky and you might not handle it right (or more likely, it takes a long time before you handle it at all). And in fact that has happened a few times, where certain block devices' feature set lagged a bit, behind what people with SSDs needed.

I suppose another easily-contrived example would be if you have a few gigabytes of data on a few terabytes of RAID, and need to [re]build the RAID. If your RAID doesn't know which blocks actually have data, then it'll need to copy/xor a few terabytes. If it's a unified system, then it can be complete after copying/xoring a few gigabytes.

Get rid of your dictator and adopt a representative democracy and it will be over. Indeed, nobody could have thought it would go on this long.

..contracts requiring NDA's that now allows customers to review secret details of products or company practices on public forums.

Can someone who favors this, explain why this might be a good thing instead of a bad thing? Maybe an example? It sounds to me like endangering such a (seemingly, to me) bad practice might be an intended consequence, not an unintended one.

I can't even see how a review made under an NDA might be useful. The premise is that the reviewer is withholding information. "The spaghetti was excellent. [censored]I am prohibited from saying anything about the sauce.[/censored]"

The idea of regarding graves as automatically for ever is relatively recent.While the wealthy might have impressive, and supposedly permanent tombstones, in medieval times people would be buried only for a few years, and then the grave dug up, the bones transferred to an ossuary, and the grave reused for another person. hence the gravedigger scene in Hamlet - the digger is recycling Yorick's grave for another occupant. So I see no problem in digging up a grave site sufficiently old that we don't know who is buried in it. The question is, as with all archaeological digs, how much to dig up now and how much to leave for later, better equipped, archaeologists.

COBOL is just as disadvantaged in dealing with an SQL database. All that DATA DIVISION syntax is about reading and writing flat files, not interacting with a database engine in a separate executable. (It's a while since I've done any COBOL so perhaps matters have changed now, but COBOL was always about fixed width record flat files).

My Java code needs no changes if table formats changed (things like added columns) because I try to use the supplied classes and the JDBC properly (and also take the time to make sure the database is designed right - such as using views, so the underlying data format can be changed without requiring all the things that depend on it to change).

SQL didn't exist until long after COBOL was a major thing. What COBOL is good at is dealing with fixed width record format flat files, which was a common way of storing stuff when COBOL was first invented. When you have a large complex system that's been going for decades, is fully debugged, and just works there is a huge cost in rewriting it that may just not be worth it.

I started trying to think of situations where a person can have a wrist-worn PC but cannot have a handheld PC with them -- situations where people are constrained for some reason.

The obvious thing most people come up with, is where it's a natural or convenient constraint. You don't want to be holding something extra while you're swimming or swinging an axe or climbling a cliff. I think the related applications are already well-discussed.

What about when it's an artificial constraint? I initially drew a blank on how such a constraint would emerge, until I considered situations where the served parties by the two PCs are different, so that the handheld (if one is present) might serve the user (or manufacturer) but the wrist-worn serves someone else.

Once you start thinking of situations where the user is in an adversarial (or seemingly or potentially adversarial) relationship with the owner then it gets easier to see the applications.

Prisoners, parolees, etc. It's not so much that you let them wear the Pebble or iWatch, as you make them wear it. And your prisoner doesn't need to be surfing the web or otherwise doing things where the PC needs to communicate things to the user, so many of the disadvantages relative to handhelds, become totally irrelevant. The application, of course, is monitoring: being an open spy for the government.

Somewhat similarly: children. Mom wants to know where you are, but isn't really interested in giving you Yet Another porn terminal. Quit fapping and get back to your homework at the libra-- your friend's house?!? Get back to the library!

Marketing. Get 'em cheap enough, and these could replace your "frequent shopper" cards as your cookie. Wear our wrist PC as you walk around our store and check out, for a 2% discount. The application is spying, again. And I guess as long as it has a speaker, it can play location-triggered ads. "Whoa, you just walked right by our delicious canned spoo and instant flarn. Are you sure you don't want some?" The idea here is that you could perform the application with a handheld, but the existing handheld PC would be too pro-user so it might not really play the ads out loud and it might report false travel data. So you want the pro-store computer to be a physically different one. Then it becomes a wrist-worn simply because that's smaller and cheaper ($10 instead of $100).

Sweatshops. The Slurm factory employees are spending too much time on bathroom breaks, and texting their friends. Well, the employee wearable PC doesn't do texts, and it delivers a shock after 90 seconds in the bathroom. If a supervisor ever sees you without your wearable, you're fired.

Jealous spouses. Hubby's "Love Watch" chemical sensors are picking up interesting volatiles: perfume? My, he sure is breathing hard and the GPS has him in a residential neighborhood, not at the mid-town office. Oh, those are just fringe use cases: everyone knows the real purpose of the Love Watch is that it instantly relays every time you speak "I love you" into it. (OMG, that last part is so sickening that I bet a variant of this product already exists today.)

Think in terms of why you might want to "plant" (though not necessarily with subterfuge) your computer on someone else, to be your agent rather than the wearer's. Those may be the best applications for wrist-worn PCs.

The first two are easy... but the last one? Yikes!

I reach at least 35 mph every day I cycle according to the Cyclemeter GPS application. It's pretty easy to reach that speed downhill.
On the level I can sustain pretty much all day long 17-18 mph.

I'm a utility cyclist, but cyclemeter tells me I sustain about 17 or 18 mph on the flat (I live in a rural area so cars are not impeding me). I commonly hit 20mph for stretches, and there are some downhill parts of my ride where I hit 35 mph. I don't wear any lycra at all either.

In cities like New York and London, it's usually that the cars cannot keep up with bicycles (not the other way around). I live in a rural area, but whenever I've cycled in congested urban areas, I've often been MUCH quicker than car traffic and usually the cars are slowing me down. Car traffic in cities is slow because there are too many cars, not because of cyclists (or little duckies).

There's even an episode of Top Gear where they prove the bicycle is the fastest method of getting across London. And that's a TV programme unashamedly biased towards the car.

That's a troll, right?

On the flat (and I'm not a lycra clad person either) I can easily keep up 17-18 mph all day. In a city, this is usually as fast (if not faster) than cars. In no way are cyclists doing this speed compatible with 3mph pedestrians. Cyclists belong on the road. (In fact where I live cyclists have a right to be on the road - cars do not, cars need to be licensed, car drivers need to be licensed).

Motorcyclists are also vulnerable road users. Should they be on the sidewalk too?

It's also human nature. We know we're slowly buggering things up, but it'll take a while. To fix it means a large change in the way we run our world, and it will be difficult and may cause mild discomfort in the short term. On the other hand we can simply deny it's happening and continue with the business as usual which is far easier and the path of least resistance. People don't want to feel guilty for driving an SUV either, it's easier and more consistent to deny that anything is happening rather than admitting that you're (an albeit tiny) part of the problem.

Temperatures have increased in the last decade. The problem is you've cherry picked one particularly warm year to use as a reference point. However if you zoom out on the graph you'll see the temperature increase trend has been relentless.

This is true but there is an underlying motive to dismissing the consensus in climate science (particularly AGW). The scientific consensus would require a significant change from business as usual. It's far easier (and you feel less guilty for doing it) to simply dismiss the consensus or try to rubbish the consensus and continue with the current business as usual, than make a meaningful change. It's just people following the path of least resistance.