Invisible wrote:

> It always amuses me how film writers seem to think that turning an
> electronic device off makes it immune to an EMP... I thought the idea
> was that an EMP will physically fry the thing like a microwave oven
> fries CDs. :-P

I've got it that way too. No matter if you turn it off, the level of
magnetic pulse coming in from say, a megaton nuclear blast will anyway
induce such a level of current in almost any conductor in range that it
will start carrying hundreds, if not thousands of volts?
-- 
Stefan Viljoen

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scott wrote:

>> Read a while ago that the RAF had to pay compensation to almost a hundred
>> car owners - one of their air-defense "steerable-array" radars went
>> haywire
>> and scanned over a road - they burned out almost every vehicle's ignition
>> and fuel injection microprocessors with the radar beam!
> 
> Haha LOL, although not so LOL if it was your car.

I agree! I'd cry my eyes out if my baby had her brains burned out when I was
just innocently driving past a radar station.
 
>> The point being an old, mechanical vehicle ignition system (carburettors,
>> a
>> rotor and points) would have just driven on with no problems.
> 
> I think that's quite a specialised failure mechanism :-)  I suspect the
> point with the ignition system is that for the same amount of money you
> can make a much more reliable electrical one than purely mechanical, given
> how a car will typically be used (ie not driving in front of an uber
> powerful radar).

Yeah, I agree. I'm amazed at the fuel consumption levels a modern
computer-controlled ignition system and fuel injection system can deliver.
I vividly remember vacations as a child, when we went down to the coast and
my dad had to manually adjust timing on the old Ford we had once we were at
sea level to prevent "pinging" when accelerating. And the joys of Saturday
afternoon carburettor cleaning, blowing out a jet (NEVER use a wire to
clean a jet!) etc. etc.

> BTW, I wonder if the police could have a portable version of such a radar,
> which they could use to stop cars...

I wonder... I'm guessing that the RAF radar was a bit more powerful than
you'd get a hand-held "speedcam" like unit to be.
-- 
Stefan Viljoen

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clipka wrote:
> Orchid XP v8 schrieb:
> 
>> Now, the *properly designed* products allow you to select some other 
>> destination with no ill effects. But all those other programs? Some of 
>> them won't let you choose at all. Others will let you choose, but 
>> never the less fail if you choose somewhere different. (WTF?)
> 
> Not seen many such ailments any time recently.

I've seen quite a few programs (mostly stuff ported from Unix, oddly 
enough) which don't like spaces in pathnames.

Wanna take a guess what the customary place to install programs is? 
Yeah, it's C:\Program Files.

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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Darren New wrote:
> Invisible wrote:
>> Ah yes, but under Windoze all programs insist on being installed on C: 
>> ;-)
> 
> Everything I have installed in programs or windows fits in 40G. And that 
> includes bunches of .NET, office, photo programs, etc etc etc.

Does that include Team Fortress 2, HalfLife 2, Counter-Strike: Source, 
Portal, Crysis, Crysis: Warhead, and Mass Effect?

Each individual game typically eats about 4GB or so...

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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>> It always amuses me how film writers seem to think that turning an
>> electronic device off makes it immune to an EMP... I thought the idea
>> was that an EMP will physically fry the thing like a microwave oven
>> fries CDs. :-P
> 
> I've got it that way too. No matter if you turn it off, the level of
> magnetic pulse coming in from say, a megaton nuclear blast will anyway
> induce such a level of current in almost any conductor in range that it
> will start carrying hundreds, if not thousands of volts?

Interesting thing: According to Wikipedia [which is never wrong], a 
nuclear explosion only generates an EMP because of the Earth's magnetic 
field. Like, if it was in space, it wouldn't do that...

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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Stefan Viljoen wrote:

> Hmm, yes, but I've often wondered if there -really- is a difference between 
> "desktop hardware" and "server hardware" - and that maybe they are designed
> for different MTBF? I. e. a "server grade" HDD will last longer if not
> regularly turned on and off, while a "desktop grade" HDD will die quicker
> if never turned off?

 From what I've seen, server-grade HDs tend to spin faster, have bigger 
caches, and have drastically lower storage capacity. (Like, they still 
sell 36GB drives. For hundreds of pounds each.) Presumably such a drive 
is a well-tested previous generation drive with the internal storage 
redundancy cranked way, way up...

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>> This is not the same as a backup.
>>
>> RAID will protect you from physical failure of a single drive. It will
>> not protect you if you accidentally delete a file, or if some virus
>> infects your PC and deletes your stuff, or if the filesystem becomes
>> corrupted somehow, or...
> 
> It depends a lot on what you're trying to protect yourself from.

Yes, yes it does.

For the average home user, if your house burns down, you're not going to 
give a **** about the holiday photos and the copy of Nero you just lost 
- YOU HAVE NOWHERE TO LIVE!! But for a business user, losing the 
building is nothing; you can *buy* another one. But losing data = you 
will be liquidated.

> There's 
> nothing, though, that says you can't create a mirrored set, let the 
> drives mirror, and then "break the mirror" and take one drive offline.  
> I've known people who have done that and used that for disaster recovery 
> when upgrading systems.

This is a very, very dumb way to do backup. A file-level copy will be 
drastically faster. (It doesn't involve mirroring all the useless empty 
sectors.) IME, mirroring a disk typically takes something like 10 hours, 
regardless of capacity. (Lower-capacity drives are usually 
correspondingly slower too.)

Also, if you do a file-level copy, you have options such as compressing 
the data and putting multiple backups on a single backup harddisk, doing 
differential or otherwise partial backups, and so forth.

>> An often-encountered backup strategy is to copy everything onto an
>> external USB HD and then put that somewhere. I'm not sure that all this
>> turning the drive on and off won't just wear it out faster.
> 
> See my anecdotal evidence in reply to Stefan.  Two identical units, one 
> powered on and off regularly, one that was left on 24x7.  Guess which one 
> failed?  Not the one that has been turned on and off regularly for 5 
> years now.  The one that was plugged in and running for 3 years solid.

In theory, until the disks are spinning at full speed, you don't get 
that "cushion of air" for the heads to "fly" on, which should result in 
wear. Of course, no doubt manufacturers know all about this and have 
come up with ways to at least reduce the problem...

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>> Wait - your garage door can open by itself?
>>
>> Man, if we want to open ours, we have to use *muscle power*. ;-)
> 
> Hey, that's the U.S. of A. - they don't use muscle power for /anything/, 
> unless they happen to be football pros...

I thought baseball was the national game of America?

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clipka wrote:
> Tim Cook schrieb:
> 
>> Like I maybe mentioned, it's an eSATA, so has a totally different 
>> connection and can't test it in desktop of housemate.
> 
> Nobody in reach with eSATA on their machine? Neighbors? Friends? Work 
> colleagues?

No chance of buying an adaptor?

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>> I don't know, man... Backing up spinning disk to... spinning disk? Is 
>> that such a sensible idea?
> 
> Why not? It's a backup. It's not like you can read a tape without 
> spinning it. What are you going to back it up to, FLASH RAM?

Tape operates at much lower speeds. And since the only people who use 
tape are people who want seriously reliable backup storage, it tends to 
be very well engineered. (And stupidly expensive...)

>> (Then again, I don't have any hard data on the reliability of HD 
>> verses tape verses CD. I've heard that spinning HD up and down wears 
>> it out faster than keeping it spinning, but I don't know if that's 
>> true...)
> 
> And by the time you actually have to worry about that, those drives will 
> be your temp drives and you'll be buying 15TB SSDs for the next computer.

Heh. Dream on. ;-)

Harddrives do die occasionally. It's quite rare, but it does happen from 
time to time. Either you accept the resulting data loss, or you take a 
backup copy.

Myself, I don't have any backup copies because I can't think of anything 
nearly big enough to backup to...

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