Catch up on stories from the past week (and beyond) at the Slashdot story archive

 



Forgot your password?
typodupeerror

Comment: Re:Since when is AMT controversial? (Score 2) 89

by fuzzyfuzzyfungus (#48936245) Attached to: FSF-Endorsed Libreboot X200 Laptop Comes With Intel's AMT Removed
A mixture of both. The AMT system includes a dedicated ARC cpu, which runs its own OS and functions independently of the host to a large degree; but also can see into, and sometimes make use of, some of the hardware visible to the host system(details depend on version). For communication, for instance, the AMT system has access to the wired NIC below the OS's view(wireless NICs are more complex, I think AMT can do a direct connection to a trusted AP if configured to do so; but can't do VPN without piggybacking on the host OS), and it also has enough hooks into the various peripherals that it can do remote KVM in hardware, by emulating HID devices and snooping the framebuffer, mount an .iso as though it were a connected SATA device, and access some storage and memory locations that are also accessible to the host OS or programs, in order to gather data on system health, software versions, etc.

I'm not exactly sure how the BIOS/UEFI flash and the flash that stores the AMT firmware are related to one another. On computers with AMT, a 'bios update' will often flash both; but I don't know if that's because they are just different areas of the same SPI flash chip, or whether it's just a convenience bundling of two nearly unrelated updaters.

Comment: Re:Manual config (Score 1) 39

by fuzzyfuzzyfungus (#48936033) Attached to: D-Link Routers Vulnerable To DNS Hijacking
They all tend to be fairly miserable(though thermal issues are often more a product of the desire to have more space for ugly branding and fewer vents, which can be fixed with a bit of applied violence); but I do have to give the hardware credit for often being rather amazing for the price. The firmware is shit more or less across the board; but it is astounding how much actual computer they can cram into a $20 router.

Comment: Re:Since when is AMT controversial? (Score 1) 89

by fuzzyfuzzyfungus (#48935903) Attached to: FSF-Endorsed Libreboot X200 Laptop Comes With Intel's AMT Removed
Any remote management tool would be a 'backdoor', except that it is put in place by the owner for their convenience and with their consent.

AMT is a particularly powerful, and somewhat opaque, management tool. Anyone who suspects the possibility that(deliberately, or by mistake) those very, very, useful capabilities might be available to others under some circumstances would naturally be suspicious of it.

And, for the FSF and those who share their concerns, the fact that it is a wholly proprietary(and tricky to remove or replace) blob embedded in the brainstem of their computer is not something that would make them happy.

Comment: Re:N(N+1)/2 spares (Score 1) 236

We propose to eliminate [disk replacement] calls by building disk arrays that contain enough spare disks to operate without any human intervention during their whole lifetime ...we have simulated the behaviour of two-dimensional disk arrays with N parity disks and N(N – 1)/2 data disks under realistic failure and repair assumptions. Our conclusion is that having N(N + 1)/2 spare disks is more than enough to achieve a 99.999 percent probability of not losing data over four years.

Are you seriously telling me you read that and get that they're creating a disk array out of spare disks that can provide 5-nines reliability for four years without involving any disk replacement? Methinks you need to invest some serious effort on your reading comprehension skills. Not to mention your sanity-check skills.

Comment: Re:even when it is powered off. (Score 3, Informative) 89

by fuzzyfuzzyfungus (#48935555) Attached to: FSF-Endorsed Libreboot X200 Laptop Comes With Intel's AMT Removed
That may differ between laptops and desktops, or between AMT versions. On the desktops I've seen the AMT stuff is active if the PC is plugged in, regardless of its power state. Some of the capabilities of the AMT system cannot be used if the host PC is off; but the system itself runs on a separate processor and only turns off if the PSU is unpowered. Laptops may need to be more conservative, for the sake of retaining battery life while inactive.

Comment: Re:And how many weeks will NBD support take?` (Score 1) 99

Speaking of Dell, failure, and lawyers, back during the 'capacitor plague' era the law firm that Dell retained to fight capacitor-plague related lawsuits was itself stuck with capacitor-plagued Dells. I can only imagine that their IT people saw the humor in the situation. True story.

Comment: Re:OK, based upon notebook shopping thus far (Score 1) 99

If your machinist is good enough you can probably fit a V12 in a wristwatch. It's just that all those cylinders will be very, very, tiny and the actual power generated will be rather unimpressive.

If you wanted the same effect in a laptop, you could probably add a GTX980 (250watt TDP) to this laptop as long as it was clocked at maybe 50MHz, rather than the usual 1100.

Comment: Re:OK, based upon notebook shopping thus far (Score 1) 99

The trouble is that the entire i5-5200u, CPU and GPU, is also 15 watt part. Unless Dell is somehow just throwing away usable space inside that case, I suspect that fan noise, battery life, or both are going to hurt if you double the demands of the core silicon.

I don't know exactly how much you save if you wholly disable the GPU portion of the intel part, probably a little less than half, so even in that case you are talking about a pretty substantial bump in thermal load.

I don't deny that the integrated graphics are feeble, merely note that you are unlikely to get anything exciting into hardware that size. Even if we assume 100% efficient disabling of the integrated GPU, and savings of ~50%, a discrete GPU arrangement would involve a 50% TDP increase. If the integrated graphics can't be cleanly disabled, it might creep closer to doubling. I doubt that that would be a pleasant machine to work with.

Comment: Re:N(N+1)/2 spares (Score 1) 236

That's certainly what it says in the summary. As for distinguishing between parity and spares - I should think that would be obvious: the parity disks are in active use, the array can't detect/correct errors without them. The spares meanwhile are just sitting there, presumably powered down, until one of the active disks needs to be replaced.

As for the equivalence in the number of spares... I suspect it's not exactly coincidence, more like human nature: "Okay, we've got a cool 2D parity system - let's see just how long it will maintain 5-nines reliability if we give it one spare for every active drive. Over four years! Cool, for the press release lets juice it up a little and rephrase that as 'more than enough for five nines for four years'."

Comment: Re:Only 4 years? (Score 1) 236

Standard combinatorial statistics, assuming failure probability is constant over time. Obviously things get more complicated if the failure rate varies over time, but it's good for a first-order approximation. In reality the "bathtub curve" of drive failures means those first few thousand hours have a much higher failure rate, so the actual 5-nines reliability duration will be much lower.

Assume you have a 0.99999 probability of not failing in 1.4427 hours
After the first 1.4427 hours you have 0.99999 chance of having not failed.
During the second period you have another 0.99999 chance of non-failure, assuming you didn't fail in the first period - for a total non-failure chance of 0.99999*0.99999 ~= 0.99998
During the third period you again have a 0.99999 chance of continued non-failure, for a lifetime nonfailure chance of 0.99999^3 ~= 0.99997
After 100,000 hours your chance of having not failed is 0.99999^(100,000h/1.4427h) = 0.5

Comment: Re:"Broadband" is a stupid name (Score 1) 331

by Immerman (#48933367) Attached to: FCC Officially Approves Change In the Definition of Broadband

Because the term has been redefined to mean "high speed" by non-technical sorts. Same reason they call it a a DSL or cable modem, despite the fact that nothing is being modulated or demodulated. It happens, deal with it. Hell, there was a time when "awesome" meant something that inspired awe, and "faggot" referred to a bundle of thin sticks to be used as fuel.

Meanwhile the term "broadband" has been enshrined in law, and is the basis for various government subsidies, etc.

Besides, broadband isn't that stupid a name - sure, it no longer refers to a broad band of frequencies used in transmission, but it does refer to a broad data bandwidth, as opposed to the narrow data bandwidth offered by an old-fashioned modem or serial port.

Comment: Re:Headline stupidity (Score 1) 133

by fuzzyfuzzyfungus (#48933053) Attached to: Former NATO Nuclear Bunker Now an 'Airless' Unmanned Data Center
For long term maintenance of a low oxygen environment they are probably using a Nitrogen generator of some flavor. If you want the job done fast, the ready availability of liquid nitrogen is very handy: let one liter of that boil off and you get almost 700 of pure nitrogen. Just carry it down and dump it.

Comment: Re:How is maintenance performed? (Score 1) 133

by fuzzyfuzzyfungus (#48932979) Attached to: Former NATO Nuclear Bunker Now an 'Airless' Unmanned Data Center
My cynical suspicion is that have a datacenter in an underground oxygen-purged bunker is something you cost-justify under 'disaster recovery' or similar; but actually do because of a vague, gnawing, ill-defined dissatisfaction with the fact that your life is basically as safe as it is tedious. The same sort of thing as why really boring federal agencies build huge SCIFs and random suburbanites lovingly shop for tacticool accessories to cram onto their AR-15.

That aside, I assume that they got it for peanuts compared to the original build cost, since abandoned bunkers aren't terribly high-value real estate(and potentially turn into blighted little holes if you don't keep them locked and have a cop watch the entrance moderately closely), and a cold war bunker is probably nice and sturdy, trivial to provide physical security for, and not too much more inconvenient than a situation where equipment has to be taken upstairs by cargo elevator. The oxygen purge seems harder to justify except for the cool factor, though.

"Someone's been mean to you! Tell me who it is, so I can punch him tastefully." -- Ralph Bakshi's Mighty Mouse

Working...