Well, off the top of my head, I think I usually turn off apmd, atd, autofs, keytable, kudzu, random, rawdevices, rhnsd, sendmail, xinetd.
Obviously if you want to run servers, then start those. For telnet and some other servers you will need xinetd running as well. You need gpm if you use the mouse in console -- if not you can turn that off. If you don't need to use NFS, you can turn off nfs, nfslock, and portmap.
Does it really take that long?
on
Booting Linux Faster
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· Score: 2, Informative
I still remember the days when I installed Slackware off floppies, and unless my memory is failing much faster than anticipated, I don't think the kernel itself takes much longer to boot than it ever did.
What definitely does take longer is starting all the system services. I know that an out-of-box RedHat installation starts an insane number of (mostly useless) services on startup. The first thing I always do when installing a RH box is run 'ntsysv' and disable all the crud.
The 'kudzu' utility is the worst offender. It checks the system for any new hardware or peripherals. There's no need for this to run on every single boot!
And BTW... Why are you rebooting a Linux box anyway?;-)
I just objected that two orthogonal values could be combined to give a meaningful value.
Would you say that "pressure" and "volume" are orthogonal units? Sure, I would too. But if you multiply them, interestingly enough you get another meaningful unit: energy. Pressure*Volume=Energy.
The fact that they are "orthogonal" means nothing. The rule in science is that you cannot add dissimilar units. You can multiply and divide them all you want.
The nice thing about multiplying two quantities is that if either quantity doubles, the product also doubles. Therefore one of the best ways to express a combination of two "orthogonal" quantities is via multiplication. (I have no idea how the Torino scale works, but it probably isn't an extremely complex formula).
Go read some web sites about dimensional analysis and you'll start to understand why it's legitimate to combine dissimilar units in certain ways.
He's using a very specific definition of entropy -- the average number of bits required to transmit a symbol of the source alphabet. In order to avoid confusion with thermodynamic entropy, people sometimes use the term "negentropy," or "informational entropy."
The definition of information entropy is -sum(p(x)*log(p(x)),x) where x ranges over all possible outcomes of the random source, and p(x) is the probability of such an outcome.
It can be interpretted as the average number of bits required to transmit a source symbol.
You are not the first to notice the relationship between informational entropy and thermodynamic entropy. This is the reason Shannon coined it "entropy" in the first place. As information theory advances, people are discovering more and more than thermodynamics and information are more tightly linked than we had ever imagined...
Now, as to your statement that a jumbled word has no more entropy than an unjumbled one -- it depends on how you define "source symbol." If the symbols are individual letters, then you are correct. Merely changing the order of the letters does not alter their relative frequencies. But instead of examining single letters at a time, we might examine pairs (digrams). Scrambling the letters disrupts the digrams and therefore alters their frequencies, and this changes their prior probabilities, which in turn influences the entropy. You can imagine that this argument extends further, we could examine trigrams, or n-grams in general. Or we can treat entire words themselves as symbols.
If you find this stuff interesting, Google around for "information theory," "Shannon entropy," "mutual information." It applies to cryptography, quantum computation, error correction, signal modulation, pretty much everything under the sun.
Tht isnt s srprsng cnsdrng y cn rmv ll th vwls nd y cn stll rd th txt. Ll t prvs s tht hmns r gd t fltrng ns nd rcnstrctng mssng nfrmtn. W r nfrmtn prcssng mchns ftr ll.
That's because you Germans have words like "Oberammergaueralpenkrauterdelikatessenfruhstucksk ase". Knowing the first and last letter of such a word is little help;-)
(Sorry, it appears Slashdot won't let me post the diacritic marks on those letters)
To what would you ground it to? You're in the air...
You ground it to the airframe. What's so magical about being grounded to the physical GROUND? After all, Earth is also just a big ball floating in space...
A "ground" is just a place to dump charge to when you don't want it sitting around creating unwanted potential. It doesn't have to be "the ground," just a spot where the excess charge can be disposed of. The frame of an airplane is like a giant capacitor plate. A small charge flowing in and out of it will not change its potential by any measurable amount.
FYI, the physical earth is a popular grounding point because people tend to stand on the earth, therefore you want circuit ground and human ground to be the same to avoid shock.
The problem as I see it, is that too many people are studying Computer Science and then going out and programming for a living. These two things just don't mix. Computer Science isn't about programming, it's more about mathematics and algorithmic thinking. A computer science program doesn't teach software engineering -- as well it shouldn't.
The problem is there is no standardized Software Engineering curriculum anywhere. Programmers shouldn't be studying computer science, they should be studying engineering.
So yes, they should be teaching security concepts to programmers. But don't expect this to happen in computer science. CS shouldn't be coopted into some kind of engineering discipline, because that's not what it is. What we need are true Software Engineering schools.
I love how Slashdotters talk.. "I have no sympathy for..." "I will not tolerate..." "It is unacceptable that..." Oh really? You have no sympathy eh? You won't tolerate it will you? It's unacceptable is it?
You aren't kings of the world, kings of morality, or kings of anything else. Conceited bastards.
The solution is simple. If you want WHOIS contact information, you must make a request through snail mail. This would prevent mass harvesting of the information while still keeping it public.
I think you missed the point. Linus isn't interested in what the public thinks. He's trying to piss off Darl and make him do something even more ridiculous than he already has.
However, you choose who you work for. By working for a company, you support its actions. You may not believe these actions are correct, but if you do nothing to change it, you are as guilty as those driving that bus.
Are you "hard of thinking" or something? Damage is saying "We won't hire you if you came from SCO." Why the hell should they quit, when the rest of the industry is telling them "Tough shit, you worked for SCO, and even if you quit for ideological reasons now that you know they are full of shit, we still aren't going to hire you."
That's ridiculous. Suppose I lived in a college dorm, and somebody swiped my digital camera. On the camera were several photographs of a recent cherished moment (such as graduation from high school). Not wanting to lose the photographs, and hoping that whoever took the camera was just drunk and might feel bad if they knew what was on it, I post a message on the dorm bulletin board saying "Please, if you have my camera, please return it to me. It has several priceless photographs on it. No questions asked -- I just want my photographs back."
According to you, it would be illegal for me to make such a posting. What a stupid law.
Wait a minute. You're saying that if a person wants to receive psychological help because he doesn't want to have urges toward children, then the shrink is required to bust him?
Make sure the next time I feel naughty urges that I don't try to seek help for them! I'll just stew quietly in my own sickness.
Normally, if you shoot yourself in the head with a paintball gun at close range, it'll fucking hurt, leave a giant bruise, etc. But say that somebody installed an overpressurized CO2 canister in the gun, causing the paintball to come out at a higher velocity than expected, causing irreversible brain damage on impact.
The fact is, you're still an idiot for shooting yourself in the head with a paintball gun.
The woman was a retard for placing a paper coffee cup between her legs. What happened to personal responsiblity? Shit happens, and sometimes coffee is hotter than you might expect. She should have thought of that before blindly trusting some kid making minimum wage at McDonalds to check the temperature. The blame is on her, as well, and she got a Darwinian wakeup call.
Slashdot Mirror
Me: "I need six satellites, pronto."
SD: "Would that be launched, or unlaunched, sir?"
Obviously if you want to run servers, then start those. For telnet and some other servers you will need xinetd running as well. You need gpm if you use the mouse in console -- if not you can turn that off. If you don't need to use NFS, you can turn off nfs, nfslock, and portmap.
It's pretty easy to distinguish. The dishonest companies will be 1000, the honest ones 1024 :-)
Yeah, and metric will also catch on in the U.S.
What definitely does take longer is starting all the system services. I know that an out-of-box RedHat installation starts an insane number of (mostly useless) services on startup. The first thing I always do when installing a RH box is run 'ntsysv' and disable all the crud.
The 'kudzu' utility is the worst offender. It checks the system for any new hardware or peripherals. There's no need for this to run on every single boot!
And BTW... Why are you rebooting a Linux box anyway? ;-)
Would you say that "pressure" and "volume" are orthogonal units? Sure, I would too. But if you multiply them, interestingly enough you get another meaningful unit: energy. Pressure*Volume=Energy.
The fact that they are "orthogonal" means nothing. The rule in science is that you cannot add dissimilar units. You can multiply and divide them all you want.
The nice thing about multiplying two quantities is that if either quantity doubles, the product also doubles. Therefore one of the best ways to express a combination of two "orthogonal" quantities is via multiplication. (I have no idea how the Torino scale works, but it probably isn't an extremely complex formula).
Go read some web sites about dimensional analysis and you'll start to understand why it's legitimate to combine dissimilar units in certain ways.
Let's punish rape victims for getting raped. After all, they were asking for it! They should have known better than to wear such provocative clothing.
The definition of information entropy is -sum(p(x)*log(p(x)),x) where x ranges over all possible outcomes of the random source, and p(x) is the probability of such an outcome.
It can be interpretted as the average number of bits required to transmit a source symbol.
You are not the first to notice the relationship between informational entropy and thermodynamic entropy. This is the reason Shannon coined it "entropy" in the first place. As information theory advances, people are discovering more and more than thermodynamics and information are more tightly linked than we had ever imagined...
Now, as to your statement that a jumbled word has no more entropy than an unjumbled one -- it depends on how you define "source symbol." If the symbols are individual letters, then you are correct. Merely changing the order of the letters does not alter their relative frequencies. But instead of examining single letters at a time, we might examine pairs (digrams). Scrambling the letters disrupts the digrams and therefore alters their frequencies, and this changes their prior probabilities, which in turn influences the entropy. You can imagine that this argument extends further, we could examine trigrams, or n-grams in general. Or we can treat entire words themselves as symbols.
If you find this stuff interesting, Google around for "information theory," "Shannon entropy," "mutual information." It applies to cryptography, quantum computation, error correction, signal modulation, pretty much everything under the sun.
Have a drink?
Let's do away with those silly products UNIX, Linux, and X-Windows!
Tht isnt s srprsng cnsdrng y cn rmv ll th vwls nd y cn stll rd th txt. Ll t prvs s tht hmns r gd t fltrng ns nd rcnstrctng mssng nfrmtn. W r nfrmtn prcssng mchns ftr ll.
(Sorry, it appears Slashdot won't let me post the diacritic marks on those letters)
I think a more obvious answer would be to use fiber optics instead of wires. It avoids all the problems you mention.
You ground it to the airframe. What's so magical about being grounded to the physical GROUND? After all, Earth is also just a big ball floating in space...
A "ground" is just a place to dump charge to when you don't want it sitting around creating unwanted potential. It doesn't have to be "the ground," just a spot where the excess charge can be disposed of. The frame of an airplane is like a giant capacitor plate. A small charge flowing in and out of it will not change its potential by any measurable amount.
FYI, the physical earth is a popular grounding point because people tend to stand on the earth, therefore you want circuit ground and human ground to be the same to avoid shock.
The problem as I see it, is that too many people are studying Computer Science and then going out and programming for a living. These two things just don't mix. Computer Science isn't about programming, it's more about mathematics and algorithmic thinking. A computer science program doesn't teach software engineering -- as well it shouldn't.
The problem is there is no standardized Software Engineering curriculum anywhere. Programmers shouldn't be studying computer science, they should be studying engineering.
So yes, they should be teaching security concepts to programmers. But don't expect this to happen in computer science. CS shouldn't be coopted into some kind of engineering discipline, because that's not what it is. What we need are true Software Engineering schools.
cat /boot/vmlinuz > /dev/dsp
You aren't kings of the world, kings of morality, or kings of anything else. Conceited bastards.
The solution is simple. If you want WHOIS contact information, you must make a request through snail mail. This would prevent mass harvesting of the information while still keeping it public.
Don't listen to the fools who claim you were a monster; they're just short sighted. One day, all of humanity may have you to thank for our survival.
Actually, it was quite calm and composed. Methinks you have a stick up your ass.
I think you missed the point. Linus isn't interested in what the public thinks. He's trying to piss off Darl and make him do something even more ridiculous than he already has.
Are you "hard of thinking" or something? Damage is saying "We won't hire you if you came from SCO." Why the hell should they quit, when the rest of the industry is telling them "Tough shit, you worked for SCO, and even if you quit for ideological reasons now that you know they are full of shit, we still aren't going to hire you."
How fucking childish.
Try as I might, I cannot identify any misspelled words in that snippet.
According to you, it would be illegal for me to make such a posting. What a stupid law.
Make sure the next time I feel naughty urges that I don't try to seek help for them! I'll just stew quietly in my own sickness.
Normally, if you shoot yourself in the head with a paintball gun at close range, it'll fucking hurt, leave a giant bruise, etc. But say that somebody installed an overpressurized CO2 canister in the gun, causing the paintball to come out at a higher velocity than expected, causing irreversible brain damage on impact.
The fact is, you're still an idiot for shooting yourself in the head with a paintball gun.
The woman was a retard for placing a paper coffee cup between her legs. What happened to personal responsiblity? Shit happens, and sometimes coffee is hotter than you might expect. She should have thought of that before blindly trusting some kid making minimum wage at McDonalds to check the temperature. The blame is on her, as well, and she got a Darwinian wakeup call.