T1 is just a 1.5Mbps digital pair in each direction. All you need is a cross-over cable to connect two CSUs back-to-back.
Hmm... okay I'm using HDSL "T1"s here -- perhaps that's my problem.
There are four pairs, T, T1, R and R1. I cross-connect them and nada. I try various combos and while one end sees the other they both indicate that both loops are down. Also neither unit can configure the encoding or framing. The smarter of the two units has a serial port and all settings are only settable from the remote (i.e. CO) end.
The problem with doing T1 over dry pairs is that you can't go very far at all - that's how telcos justify the big $$ for T1 - they have to install repeaters.
Depending on how far you classify as far... An HDSL T1 will reach farther than any HDSL2 circuit simply because it's over two pair and can be a little more lax on transmit and more sensitive on receive. A quick check on one of our AS5248s shows the short cablelength provisioning gets us to 655ft. Not terribly long, you're right.. I thought it was longer for the short cablelength.:-)
These days, telcos minimize the use of repeaters by using broadband (HDSL?) from the CO to your NIU.
Are standard (i.e. the true T1s still available? These Adtran units are HDSL T1s and can indeed be used with repeaters.
Has anyone ever ordered a dry pair from Pacific Bell? I tried once - talked to a dozen of those numbskulls and none of them had heard of it.
When we order ours from Bell Canada we went though hell the first time but the rep was nice enough to tell us that in future, just ask for a "Class A Signal Channel" -- and to make sure to have it installed with no taps or coils. If you're not getting a signal keep pestering them -- one of our loops had coils on them that (supposedly) weren't on any of the line drawings that the techs had access to.
Wrong. You learn by getting trained by authorized professionals who know how a piece of hardware works. That way you also get a certificate showing to your potential employer that you really do know about something.
I'm afraid it's you who is wrong. I don't know how your post was moderated as insightful but that's the moderation system for you. The original poster was correct in how 90% of people learn things. They go the formal education route only to get a piece of paper or, more commonly, if they really don't want to learn but have the paper that says they do know.
Here's a fun excercise: pick a company or a field of endeavor. Count the number of degreed people who actually know what they're doing compared to those who don't know anything. Now count the number of people who have no degrees but know what they're doing and compare to those without a degree and know nothing. What percentage of degreed people know what they're doing compared to the percentage of non-degreed people? The answer is surprising if you haven't done it before and the explanation is simple: The degreed people got in because of the paper and maybe because they know what they're up to, while the nondegreed people can't get in if they don't know what's what.
People with degrees usually fetch a higher starting salary but after a few years the wheat is seperated from the chaff and the smart rise above, just as they do in practically everything. If you know what you're doing and can't get ahead, leave and find another company with clueful management. If nothing else you'll find out for sure if you know what you're doing or not.:-)
My career is relatively new (in its 7th year) but I have no need for that piece of paper saying I know what I'm doing. I'll get my degree to fill in holes in my education but aside from that... it's practically useless. The headhunters and subsequent interviewers I run across want to know is what I'm doing in my current job and what I've done before, not what I learned in school.
I've never said that doing it on your own is easier, but it was certainly the best route for me. I hear that places like Germany always refer back to your education no matter what your experience, so this post is definately geographically-tied.
You're right about bandwidth charges but I think you're way off with blaming "shitty dry pair DSL" with quality. I spec Pairgain Megabit Modem 300S (2.048Mbps full duplex) -- they aren't rate-adaptive but rather use a little selector-switch to set the WAN speed. I have yet to have a single problem with them and we've got over 25 pair in service. Link speeds are better than spec (our area has larger gague wire trunks than standard) and it just never goes down. Far better than Wireless if you ask me. We had a competitor to the north set up most of his links in the winter and when spring came everyone's link took a big shit. Not to mention humidity effects.
BTW: ALL DSL works over dry copper aside for the g.Lite implementations which are piggybacked on top of a regular phone line.
You can do a similar thing with T-1s, just get 2 dry pairs and wire correctly.
Incorrect. T1s require a head (CO) end and a CPE end. I have a pair of Pairgain HRUs and they do not work together. One end needs to clock the other and (optionally) power the remote end. I got away with powering them with 120VDC (just rectify the AC line and it works well) but the ends can't communicate since one isn't a CO end. It would be nice though.:-)
I do do SDSL stuff all the time though; it works VERY well. Especially out here since our trunks use larger wire and you get just a little more distance than what's spec'd.:-)
Re:It's another advantage over Micro$hit
on
Direct3D on Linux?
·
· Score: 1
The capability for Linux to deploy all software from any operating system architecture should be a goal of the Linux community... it's a clear advantage over the limitations of Microsoft products.
Isn't that pretty much the same thing OS/2 said? We all know how well that works. The only place I see OS/2 now is at my bank.
The reason you ask slashdot is to get the answers that you won't get from rounding up the usual suspects (google, etc.), or to get a good, custom-filtered synopsis of what you would get from other sources (you do a search, find info on PC104 or whatever and then you have to wade through all the sales pitches and personal experiences not relevant to the reason for your interest, big chaff to wheat ratio).
I agree. Totally. But it sounds like this guy hasn't even done basic research and that is what pissed me off. If you've done your research and have several choices you're looking for good technical opinions on, past experiences, etc. then sure, ask slashdot. But I'm sick of the "I want to do this, how?" bullshit that seems to get in here from time to time.
Knowing what I know, I would treat every wireless network as if ALL the traffic was being transmitted over a hostile network.
Exactly. Which is why our access point is outside the firewall and wireless guys need to use the VPN to get into the network just like the telecommuters. There is no such thing as wired equivalency.
But what about getting a power supply with good filter caps, etc? Your ps might not fail, but it might cause your computer components to, especially if your UPSs have non-sine wave output or aren't online.
The regulation has to be pretty damn tight or the system will be flaky to begin with and would likely never make it into its coloation rack.
Filter caps don't do too much with switchmode supplies: the ripple is into the hundreds of kHz and smaller caps can take care of the job for the most part. (Smaller meaning
While I understand where you're going, I don't believe that crap that bad is out there. I've yet to see a shitty power supply that doesn't make itself known within the first few hours of plugging it in. If it works then, chances are it'll work for at least a few years before something going. And for $300 I'll replace a power supply every few years instead of having one costing $300 more and lasting a couple more after that.
I have been designing systems with this chip for several months now. Except for their damn standalone modules which don't have the CTRL_OUT/ signal routed to the pin these chips are Very cool. They make a smaller USB version as well.
The even cooler part is that their standalone module uses a DSP and external Flash -- you can read out their templating algorithms and use them in other systems!
K5, for example, has been able to take several direct Slashdottings on 1 VA Fullon box.
Now I like K5 as much as the next guy but I do NOT consider not being able to serve up pages as "taking a slashdotting."
I think it was last week or the week before when the last slashdotting took place over rusty's culture post. I couldn't get so much as a squeak out of K5 until hours later. Sure the server might have stayed up but it sure as hell wasn't serving up too many pages...
For far too many of the RAID controllers out there, reconfiguring or rebuilding the arrays either involves shutting down the machine and rebooting into a stand-alone utility, or "echo"ing pretty much undocumented commands into your/proc/scsi filesystem. If a drive fails, you will have downtime. The Linux RAID solutions might protect your data integrity, but they will not protect your uptime. I couldn't even imagine trying to hot-plug some new drives into the array, and then resizing the live filesystem when I needed more room. (Someone will try to refute this, and will use the word "ReiserFS" in their post, but all I have to say is that there are a lot of possible things I couldn't imagine actually doing).
Hmmm. Reiserfs will support this but I'd want to layer LVM on it before Reiserfs. As far as I know ext2 won't handle online resizing. With LVM and Reiser though it will. I've been playing with it on my home system. In a month or two I'll upgrade the office fileserver to support it. We've already got the hotswap drives in and the hardware RAID/cache, so this will just complete the upgrade path.
Things like hot plugable CPUs, or network cards, or drive controllers, are simply non-existant on Linux. Stuff like monitoring utilities that will page you in the middle of the night when one of your redundant power supplies fail, or when one of your CPUs burns out, or when one of the drives in your storage arrays dies, simply don't exist. There's a lot of stuff that you need if you want to run 24x7 that just doesn't work in Linux yet.
Interesting. I get paged if my server goes down or the internal case temp gets too high. I don't see it as much of a stretch to page if a CPU temp gets too high. Watching for casefans and whatnot is just a matter of temperature monitoring. And I do this on an external server, how about that... The main fileserver could explode and I'd still get paged that something was wrong.
A big part of that is because of posts like yours, of course -- you don't want to spend more than $2,000.00. It's pretty damned hard to build a well supported server for $2,000.00, and the people who are willing to spend the money for real support often don't care as much about Linux. You're left with a lot of after-thought solutions -- stuff that got built for something else, and just happens to work on Linux by an almost happy accident.
I'll agree here: Five 9.1G UW2 SCA drives aren't (weren't) cheap. 64M of ECC cache memory weren't cheap, and neither was the hardware RAID/cache controller it goes in to. The 20G DAT wasn't cheap, either. I don't have redundant power supplies but the server isn't that critical that I can't bring it down for 15 minutes to swap out a power supply. I've never had a power supply die on me in 5 years of network administration but then again we have a 300lb online UPS which keeps most of the nasties away from the computers. What was absolutely mission critical was that the data was safe in case of drive failure, and that it could be expanded as needed.
In short, go away troll. I"ve got a perfectly maintainable Linux server which has worked superb over the last 6 years. Had a drive fail, had a CPU cook, never lost data. I don't remember arcane commands which are echoed to/proc, I run dptutil. All I seem to do on the server is keep an eye on the logs.
You are right about one thing though: You need to consider what you're doing this for before you put a price on it. I was able to get away with about $3000 to $3500 after all the bills came in. It hasn't got hot-swappable CPUs or power supplies, but that wasn't mission critical for me. The datastore is solid and that's what mattered.
But as you're discovering, on the back end -- the database machine, where failure is much less tolerable -- it is going to be much, much harder to spec out a machine. Your example of hardware RAID is the most suprising area where Linux simply falls down. Even though cards like Compaq's SmartArray RAID controller has working Linux drivers, there are no Linux utilities.
I am sitting 15' away from a Linux machine running with a DPT Century UW2 RAID controller and I've got no problem running the Unix utilities. I can shut drives down, tune both the RAID and cache performance, silence alarms, rebuild RAID volumes, you name it. (It looks like DPT was bought by Adaptec so that may not be the exact card, mine is a hardware cache/RAID controller)
Don't spew FUD. Hell even my ancient P90 had a DPT controller in it with working utilities and that was 5 years ago!
And remember that if you buy the $200 case, you'll have to spend another $100-150 to replace the powersupply, because the one that comes with it is crap and will likely fail in weeks/months.
That is just so much bullshit. Make sure the power supply has a ball bearing fan ($12 instead of $6) and you're golden. There is no magic $300 price adder for a good power supply. Hell I'd go the distance and get a cheap case with no power supply, since I prefer to use the 48VDC provided at my colo instead of 120VAC and a shit-heavy UPS with batteries that need replacing every few years.
BTW: I've had cheap-ass sleeve-bearing fans which have lasted over 3 years, and I've also had expensive ball-bearing fans last a week. There is no magic formula that says that $300 more for a case will get you anything but a lighter wallet. Yes, ball bearing fans are much better, but not $300 better.
Have you done ANY research at all? The back of every single electronics magazine I've ever seen has dozens of ads for PC/104 systems and small embedded systems. Networking mags have some ads for this stuff too. Expensive but a good starting point for a web search. Google returns over 500k items for "small embedded computer" -- refine that a bit to "small embedded computer RS232 RS422 ethernet" gave me 263 and the first 5 results gave good info. Are you that lazy? Did you do ANY research before asking slashdot?
Now that that's over: You want to stick with the PC platform even if you go to PC104 or some small system. Why? Standard Linux will run and there's no dicking around. uClinux or any other embedded language will cost you lots in time. I assume you want this in and working now, not in three months.
ATI TV-Wonder PCI Tuner (Linux compatible, even) TV out video card - ATI, or a TNT2.. cheap.. Geforce2MX, cheap.
I was under the impression that the various ATI cards had next to nil for Decent Linux support. I know my bro's ATI All-in-wonder has shit for support.
Things like this are the reason I don't buy those all-in-one scanner/fax/copier office doodads - what if it breaks?
I envision a chassis system: Bare chassis gives you RCA A/V and the good ole' modulated out. Then you buy modules: DVD module. CPU module. RF remote module. VCR module. Optical audio module. Dolby 5.1 module. Component Video module. Satellite module. Storage modules. Networking (100bT, 100bF, 1G, etc.) The list goes on and on.
Now if something breaks the chassis powers down the section and the rest works. No need for hot-swap although that'd be cool. I'd love to design something like this a module at a time but some big company would eat me for lunch and have it out earlier simply because they have far more resources.
After reading the article I realized I had a few rights that I never knew about, namely privacy in the workplace.
Ferinstance, I didn't know it wasn't legal for the company to go rifling through my desk drawers. I always figured it was their desk and anything I left in it was open to be seen by my employers.
This opens up a whole new can of worms as far as "what can my employers actually do?" goes. The article makes a damn good point though: Companies worry about time wastage with email and web use but there are far less privacy-restricting ways of watching for abuse without resorting to monitoring everyone. I follow this policy at the ISP I do some volunteer work at. I have log-sifter scripts which flag emails with more than x number of recipients as possible spammers. I don't read everyone's email but if I get a message from my log sifter script that someone's sent 100 emails with 50 recipients each, I can then investigate further. Sounds like a damn good system to set up at work...
You're right; B&W Cameras will be better but you want LOTS of light... you'll need a pretty serious cluster of IR LEDs, even the high output ones (this all depends, of course, on the size of the area you want to illuminate and whether the surfaces reflect or absorb IR)
Especially given the theft problem (they could only steal half the camera) and the remote location, the X10 remote cameras sound good, but there's no "brightness" control on the CCD's -- it needs extremely good illumination. Most of my interior rooms aren't sufficiently lit to discern objects using the X10 remote cameras -- you have to open curtains, and then you can only see outside.
Or just do what I did: Remove the IR filter and flood the inside of the boat with IR light. The intruders won't see it but you'll have full view of them. I've done this to catch the neighbour's cat in my garbage and it works wonderfully.
Cameras vary, but most I've seen follow this basic removal procedure: Screw off the lens. If you can't get the IR filter out from that side you'll have to take the plastic assembly apart to get at the filter. (It's usually a piece of glass with a blue-ish film and it's usually right before the CCD itself, after the lens assembly. I've never seen it a part of the lens assembly.) Anyway take it out and reassemble. The camera will be practically useless during daylight (too much IR flooding the CCD) but it's awesome at night, especially with a good size IR lamp.
Where to get an IR lamp? Do some web searches or buy lamps which you can fit IR filters over. I've modded the X10 little 1" colour camera, Quickcams and a few USB cams of unknown make.
its fairly easy. use an MD5 hash to generate keys (or RIPEMD-160) which reference each file and then dump em to mysql.
While I don't know what RIPEMD-160 is (Google is my friend in a minute) I'd further the suggestion my keying to the entire file rather than just the filename -- it'll be easier to detect (exact) duplicates but I'm not sure if the overhead of MD5'ing a 5M file is worth it in hindsight.
(I'd also suggest using whatever DB you have handy and Postgres if you don't have any db currently running, but that is another flame war in and of itself.)
The brunt of my objection is against the propagation of the notions
that a) PHP doesn't make sense other than on the web, and b) that PHP
has no database abstraction layer. Of course, the fact that it works
fine as a general tool language and has database abstraction doesn't
mean that you should use it if you'd rather use something else, since
other tools will do it all fine too.
Alright. At the time I was looking at PHP, it didn't make sense for anything but the web. After looking at some of my older systems and seeing that PHP was indeed available as a generic interpreter I do have to apologize; it was ignorance rather than solid fact that led me to the conclusion that PHP is just for the web.
Regarding the abstraction of database access -- I had never heard of nor was there mention of Metabase or Pear::db in the online documentation regarding database interaction when I was learning about PHP. This has changed and this is a good change in my opinion. It will bring more people to use PHP.
In the end, I do feel rather foolish with my previous "sentence by sentence" comment. I was (still am) in the tub and the tone of your comment set me off. I don't ever think I'll look at PHP for my own use but these changes will make it a better language for others to decide to use.
So its pretty clear. PERL users like leatherman tools, PHP users prefer traditional single purpose tools. Or maybe not.
Definately maybe not.:-)
I hate leatherman tools except as a "where is my... oh fuck it, I'll use my leatherman" type of scenario. Proper pliers, proper screwdrivers and proper nailclippers are essential to me. Hell I can't even stand the dozen-in-one screwdriver sets half the time!
To me, PHP is tailored to the web and is breaking into the generic system interpeter market. Perl owns the generic system interpreter market but has uses in the web world. In my opinion Perl has a better chance at the web market than PHP does in the system interpreter market, but as I said, it's my opinion. I really haven't seen much of a speed difference between mod_php and mod_perl, I happen to love Perl's OO setup (10000000x better than C++) and although it causes me headaches from time to time, Perl's regexp abilities are far more flexible than PHPs.
Then it's irresponsible of you to be spreading myths about something you admittedly don't understand fully.
Okay, I'll call you on that one. Where am I spreading any myths? I gave my opinion and several reasons behind why I have that opinion. But let's take my original post on a point per point basis and you show me where I'm spreading myths. I don't even think you read the second comment after the first sentence.
Why learn two languages when one does 99.9% of it without breaking a sweat?
Why indeed? I don't see this as spreading myths; In fact I consider this a fact.
PHP has umpteen number of DB interfaces.
And it still does. Perhaps there are third-party classes which attempt to intgrate them (I even remember doing half of one myself) but no singular DB interface had become the main one when I was playing with PHP. This is a myth?
Perl has DBI. No matter what you talk to it's all DBI and it's fast.
I hope you don't consider this a myth.
Yeah I know about the PHP interpreter but that's just plain old hokey.
This you might construe as a myth but when I played with PHP it was hokey.
Regexps? OO? Parsing? PHP and Perl both have them
More truth.
But really when you think of it you have other things to do too... parsing logs, reformatting, search and replace... things that get done on a daily basis and are beyond the scope of "just the web". Write the module once, write it good and use it in all situations!
I stand by that statement. From what I have read now PHP has a "regular" invocation to do CGI. However it is still not as common nor (IMO) as powerful as Perl. Myths? Disinformation? Hardly. Opinion? Definately.
So now... Show me where I'm spreading myths. If you can't, then please retract your statemnt that I'm spreading myths. After all, anything else would be irresponsible.
Slashdot Mirror
T1 is just a 1.5Mbps digital pair in each direction. All you need is a cross-over cable to connect two CSUs back-to-back.
Hmm... okay I'm using HDSL "T1"s here -- perhaps that's my problem.
There are four pairs, T, T1, R and R1. I cross-connect them and nada. I try various combos and while one end sees the other they both indicate that both loops are down. Also neither unit can configure the encoding or framing. The smarter of the two units has a serial port and all settings are only settable from the remote (i.e. CO) end.
The problem with doing T1 over dry pairs is that you can't go very far at all - that's how telcos justify the big $$ for T1 - they have to install repeaters.
Depending on how far you classify as far... An HDSL T1 will reach farther than any HDSL2 circuit simply because it's over two pair and can be a little more lax on transmit and more sensitive on receive. A quick check on one of our AS5248s shows the short cablelength provisioning gets us to 655ft. Not terribly long, you're right.. I thought it was longer for the short cablelength. :-)
These days, telcos minimize the use of repeaters by using broadband (HDSL?) from the CO to your NIU.
Are standard (i.e. the true T1s still available? These Adtran units are HDSL T1s and can indeed be used with repeaters.
Has anyone ever ordered a dry pair from Pacific Bell? I tried once - talked to a dozen of those numbskulls and none of them had heard of it.
When we order ours from Bell Canada we went though hell the first time but the rep was nice enough to tell us that in future, just ask for a "Class A Signal Channel" -- and to make sure to have it installed with no taps or coils. If you're not getting a signal keep pestering them -- one of our loops had coils on them that (supposedly) weren't on any of the line drawings that the techs had access to.
I have a pair of Pairgain HRUs and they do not work together.
My mistake: HTU-R (remote) ends, not HRU. They require HTU-Cs in order to establish an end-to-end link.
Wrong. You learn by getting trained by authorized professionals who know how a piece of hardware works. That way you also get a certificate showing to your potential employer that you really do know about something.
I'm afraid it's you who is wrong. I don't know how your post was moderated as insightful but that's the moderation system for you. The original poster was correct in how 90% of people learn things. They go the formal education route only to get a piece of paper or, more commonly, if they really don't want to learn but have the paper that says they do know.
Here's a fun excercise: pick a company or a field of endeavor. Count the number of degreed people who actually know what they're doing compared to those who don't know anything. Now count the number of people who have no degrees but know what they're doing and compare to those without a degree and know nothing. What percentage of degreed people know what they're doing compared to the percentage of non-degreed people? The answer is surprising if you haven't done it before and the explanation is simple: The degreed people got in because of the paper and maybe because they know what they're up to, while the nondegreed people can't get in if they don't know what's what.
People with degrees usually fetch a higher starting salary but after a few years the wheat is seperated from the chaff and the smart rise above, just as they do in practically everything. If you know what you're doing and can't get ahead, leave and find another company with clueful management. If nothing else you'll find out for sure if you know what you're doing or not. :-)
My career is relatively new (in its 7th year) but I have no need for that piece of paper saying I know what I'm doing. I'll get my degree to fill in holes in my education but aside from that... it's practically useless. The headhunters and subsequent interviewers I run across want to know is what I'm doing in my current job and what I've done before, not what I learned in school.
I've never said that doing it on your own is easier, but it was certainly the best route for me. I hear that places like Germany always refer back to your education no matter what your experience, so this post is definately geographically-tied.
You're right about bandwidth charges but I think you're way off with blaming "shitty dry pair DSL" with quality. I spec Pairgain Megabit Modem 300S (2.048Mbps full duplex) -- they aren't rate-adaptive but rather use a little selector-switch to set the WAN speed. I have yet to have a single problem with them and we've got over 25 pair in service. Link speeds are better than spec (our area has larger gague wire trunks than standard) and it just never goes down. Far better than Wireless if you ask me. We had a competitor to the north set up most of his links in the winter and when spring came everyone's link took a big shit. Not to mention humidity effects.
BTW: ALL DSL works over dry copper aside for the g.Lite implementations which are piggybacked on top of a regular phone line.
You can do a similar thing with T-1s, just get 2 dry pairs and wire correctly.
Incorrect. T1s require a head (CO) end and a CPE end. I have a pair of Pairgain HRUs and they do not work together. One end needs to clock the other and (optionally) power the remote end. I got away with powering them with 120VDC (just rectify the AC line and it works well) but the ends can't communicate since one isn't a CO end. It would be nice though. :-)
I do do SDSL stuff all the time though; it works VERY well. Especially out here since our trunks use larger wire and you get just a little more distance than what's spec'd. :-)
The capability for Linux to deploy all software from any operating system architecture should be a goal of the Linux community... it's a clear advantage over the limitations of Microsoft products.
Isn't that pretty much the same thing OS/2 said? We all know how well that works. The only place I see OS/2 now is at my bank.
The reason you ask slashdot is to get the answers that you won't get from rounding up the usual suspects (google, etc.), or to get a good, custom-filtered synopsis of what you would get from other sources (you do a search, find info on PC104 or whatever and then you have to wade through all the sales pitches and personal experiences not relevant to the reason for your interest, big chaff to wheat ratio).
I agree. Totally. But it sounds like this guy hasn't even done basic research and that is what pissed me off. If you've done your research and have several choices you're looking for good technical opinions on, past experiences, etc. then sure, ask slashdot. But I'm sick of the "I want to do this, how?" bullshit that seems to get in here from time to time.
Knowing what I know, I would treat every wireless network as if ALL the traffic was being transmitted over a hostile network.
Exactly. Which is why our access point is outside the firewall and wireless guys need to use the VPN to get into the network just like the telecommuters. There is no such thing as wired equivalency.
Linux on your host. VMWare runs on Linux. Linux runs inside of VMWare on a Linux host.
I didn't say it'd be elegant but it sure works...
But what about getting a power supply with good filter caps, etc? Your ps might not fail, but it might cause your computer components to, especially if your UPSs have non-sine wave output or aren't online.
The regulation has to be pretty damn tight or the system will be flaky to begin with and would likely never make it into its coloation rack.
Filter caps don't do too much with switchmode supplies: the ripple is into the hundreds of kHz and smaller caps can take care of the job for the most part. (Smaller meaning
While I understand where you're going, I don't believe that crap that bad is out there. I've yet to see a shitty power supply that doesn't make itself known within the first few hours of plugging it in. If it works then, chances are it'll work for at least a few years before something going. And for $300 I'll replace a power supply every few years instead of having one costing $300 more and lasting a couple more after that.
I have been designing systems with this chip for several months now. Except for their damn standalone modules which don't have the CTRL_OUT/ signal routed to the pin these chips are Very cool. They make a smaller USB version as well.
The even cooler part is that their standalone module uses a DSP and external Flash -- you can read out their templating algorithms and use them in other systems!
K5, for example, has been able to take several direct Slashdottings on 1 VA Fullon box.
Now I like K5 as much as the next guy but I do NOT consider not being able to serve up pages as "taking a slashdotting."
I think it was last week or the week before when the last slashdotting took place over rusty's culture post. I couldn't get so much as a squeak out of K5 until hours later. Sure the server might have stayed up but it sure as hell wasn't serving up too many pages...
Sorry, I missed some of your trolling.
For far too many of the RAID controllers out there, reconfiguring or rebuilding the arrays either involves shutting down the machine and rebooting into a stand-alone utility, or "echo"ing pretty much undocumented commands into your /proc/scsi filesystem. If a drive fails, you will have downtime. The Linux RAID solutions might protect your data integrity, but they will not protect your uptime. I couldn't even imagine trying to hot-plug some new drives into the array, and then resizing the live filesystem when I needed more room. (Someone will try to refute this, and will use the word "ReiserFS" in their post, but all I have to say is that there are a lot of possible things I couldn't imagine actually doing).
Hmmm. Reiserfs will support this but I'd want to layer LVM on it before Reiserfs. As far as I know ext2 won't handle online resizing. With LVM and Reiser though it will. I've been playing with it on my home system. In a month or two I'll upgrade the office fileserver to support it. We've already got the hotswap drives in and the hardware RAID/cache, so this will just complete the upgrade path.
Things like hot plugable CPUs, or network cards, or drive controllers, are simply non-existant on Linux. Stuff like monitoring utilities that will page you in the middle of the night when one of your redundant power supplies fail, or when one of your CPUs burns out, or when one of the drives in your storage arrays dies, simply don't exist. There's a lot of stuff that you need if you want to run 24x7 that just doesn't work in Linux yet.
Interesting. I get paged if my server goes down or the internal case temp gets too high. I don't see it as much of a stretch to page if a CPU temp gets too high. Watching for casefans and whatnot is just a matter of temperature monitoring. And I do this on an external server, how about that... The main fileserver could explode and I'd still get paged that something was wrong.
A big part of that is because of posts like yours, of course -- you don't want to spend more than $2,000.00. It's pretty damned hard to build a well supported server for $2,000.00, and the people who are willing to spend the money for real support often don't care as much about Linux. You're left with a lot of after-thought solutions -- stuff that got built for something else, and just happens to work on Linux by an almost happy accident.
I'll agree here: Five 9.1G UW2 SCA drives aren't (weren't) cheap. 64M of ECC cache memory weren't cheap, and neither was the hardware RAID/cache controller it goes in to. The 20G DAT wasn't cheap, either. I don't have redundant power supplies but the server isn't that critical that I can't bring it down for 15 minutes to swap out a power supply. I've never had a power supply die on me in 5 years of network administration but then again we have a 300lb online UPS which keeps most of the nasties away from the computers. What was absolutely mission critical was that the data was safe in case of drive failure, and that it could be expanded as needed.
In short, go away troll. I"ve got a perfectly maintainable Linux server which has worked superb over the last 6 years. Had a drive fail, had a CPU cook, never lost data. I don't remember arcane commands which are echoed to /proc, I run dptutil. All I seem to do on the server is keep an eye on the logs.
You are right about one thing though: You need to consider what you're doing this for before you put a price on it. I was able to get away with about $3000 to $3500 after all the bills came in. It hasn't got hot-swappable CPUs or power supplies, but that wasn't mission critical for me. The datastore is solid and that's what mattered.
I must be dreaming, then.
But as you're discovering, on the back end -- the database machine, where failure is much less tolerable -- it is going to be much, much harder to spec out a machine. Your example of hardware RAID is the most suprising area where Linux simply falls down. Even though cards like Compaq's SmartArray RAID controller has working Linux drivers, there are no Linux utilities.
I am sitting 15' away from a Linux machine running with a DPT Century UW2 RAID controller and I've got no problem running the Unix utilities. I can shut drives down, tune both the RAID and cache performance, silence alarms, rebuild RAID volumes, you name it. (It looks like DPT was bought by Adaptec so that may not be the exact card, mine is a hardware cache/RAID controller)
Don't spew FUD. Hell even my ancient P90 had a DPT controller in it with working utilities and that was 5 years ago!
And remember that if you buy the $200 case, you'll have to spend another $100-150 to replace the powersupply, because the one that comes with it is crap and will likely fail in weeks/months.
That is just so much bullshit. Make sure the power supply has a ball bearing fan ($12 instead of $6) and you're golden. There is no magic $300 price adder for a good power supply. Hell I'd go the distance and get a cheap case with no power supply, since I prefer to use the 48VDC provided at my colo instead of 120VAC and a shit-heavy UPS with batteries that need replacing every few years.
BTW: I've had cheap-ass sleeve-bearing fans which have lasted over 3 years, and I've also had expensive ball-bearing fans last a week. There is no magic formula that says that $300 more for a case will get you anything but a lighter wallet. Yes, ball bearing fans are much better, but not $300 better.
Have you done ANY research at all? The back of every single electronics magazine I've ever seen has dozens of ads for PC/104 systems and small embedded systems. Networking mags have some ads for this stuff too. Expensive but a good starting point for a web search. Google returns over 500k items for "small embedded computer" -- refine that a bit to "small embedded computer RS232 RS422 ethernet" gave me 263 and the first 5 results gave good info. Are you that lazy? Did you do ANY research before asking slashdot?
Now that that's over: You want to stick with the PC platform even if you go to PC104 or some small system. Why? Standard Linux will run and there's no dicking around. uClinux or any other embedded language will cost you lots in time. I assume you want this in and working now, not in three months.
ATI TV-Wonder PCI Tuner (Linux compatible, even) TV out video card - ATI, or a TNT2.. cheap.. Geforce2MX, cheap.
I was under the impression that the various ATI cards had next to nil for Decent Linux support. I know my bro's ATI All-in-wonder has shit for support.
Things like this are the reason I don't buy those all-in-one scanner/fax/copier office doodads - what if it breaks?
I envision a chassis system: Bare chassis gives you RCA A/V and the good ole' modulated out. Then you buy modules: DVD module. CPU module. RF remote module. VCR module. Optical audio module. Dolby 5.1 module. Component Video module. Satellite module. Storage modules. Networking (100bT, 100bF, 1G, etc.) The list goes on and on.
Now if something breaks the chassis powers down the section and the rest works. No need for hot-swap although that'd be cool. I'd love to design something like this a module at a time but some big company would eat me for lunch and have it out earlier simply because they have far more resources.
After reading the article I realized I had a few rights that I never knew about, namely privacy in the workplace.
Ferinstance, I didn't know it wasn't legal for the company to go rifling through my desk drawers. I always figured it was their desk and anything I left in it was open to be seen by my employers.
This opens up a whole new can of worms as far as "what can my employers actually do?" goes. The article makes a damn good point though: Companies worry about time wastage with email and web use but there are far less privacy-restricting ways of watching for abuse without resorting to monitoring everyone. I follow this policy at the ISP I do some volunteer work at. I have log-sifter scripts which flag emails with more than x number of recipients as possible spammers. I don't read everyone's email but if I get a message from my log sifter script that someone's sent 100 emails with 50 recipients each, I can then investigate further. Sounds like a damn good system to set up at work...
You're right; B&W Cameras will be better but you want LOTS of light... you'll need a pretty serious cluster of IR LEDs, even the high output ones (this all depends, of course, on the size of the area you want to illuminate and whether the surfaces reflect or absorb IR)
Especially given the theft problem (they could only steal half the camera) and the remote location, the X10 remote cameras sound good, but there's no "brightness" control on the CCD's -- it needs extremely good illumination. Most of my interior rooms aren't sufficiently lit to discern objects using the X10 remote cameras -- you have to open curtains, and then you can only see outside.
Or just do what I did: Remove the IR filter and flood the inside of the boat with IR light. The intruders won't see it but you'll have full view of them. I've done this to catch the neighbour's cat in my garbage and it works wonderfully.
Cameras vary, but most I've seen follow this basic removal procedure: Screw off the lens. If you can't get the IR filter out from that side you'll have to take the plastic assembly apart to get at the filter. (It's usually a piece of glass with a blue-ish film and it's usually right before the CCD itself, after the lens assembly. I've never seen it a part of the lens assembly.) Anyway take it out and reassemble. The camera will be practically useless during daylight (too much IR flooding the CCD) but it's awesome at night, especially with a good size IR lamp.
Where to get an IR lamp? Do some web searches or buy lamps which you can fit IR filters over. I've modded the X10 little 1" colour camera, Quickcams and a few USB cams of unknown make.
its fairly easy. use an MD5 hash to generate keys (or RIPEMD-160) which reference each file and then dump em to mysql.
While I don't know what RIPEMD-160 is (Google is my friend in a minute) I'd further the suggestion my keying to the entire file rather than just the filename -- it'll be easier to detect (exact) duplicates but I'm not sure if the overhead of MD5'ing a 5M file is worth it in hindsight.
(I'd also suggest using whatever DB you have handy and Postgres if you don't have any db currently running, but that is another flame war in and of itself.)
The brunt of my objection is against the propagation of the notions that a) PHP doesn't make sense other than on the web, and b) that PHP has no database abstraction layer. Of course, the fact that it works fine as a general tool language and has database abstraction doesn't mean that you should use it if you'd rather use something else, since other tools will do it all fine too.
Alright. At the time I was looking at PHP, it didn't make sense for anything but the web. After looking at some of my older systems and seeing that PHP was indeed available as a generic interpreter I do have to apologize; it was ignorance rather than solid fact that led me to the conclusion that PHP is just for the web.
Regarding the abstraction of database access -- I had never heard of nor was there mention of Metabase or Pear::db in the online documentation regarding database interaction when I was learning about PHP. This has changed and this is a good change in my opinion. It will bring more people to use PHP.
In the end, I do feel rather foolish with my previous "sentence by sentence" comment. I was (still am) in the tub and the tone of your comment set me off. I don't ever think I'll look at PHP for my own use but these changes will make it a better language for others to decide to use.
So its pretty clear. PERL users like leatherman tools, PHP users prefer traditional single purpose tools. Or maybe not.
Definately maybe not. :-)
I hate leatherman tools except as a "where is my... oh fuck it, I'll use my leatherman" type of scenario. Proper pliers, proper screwdrivers and proper nailclippers are essential to me. Hell I can't even stand the dozen-in-one screwdriver sets half the time!
To me, PHP is tailored to the web and is breaking into the generic system interpeter market. Perl owns the generic system interpreter market but has uses in the web world. In my opinion Perl has a better chance at the web market than PHP does in the system interpreter market, but as I said, it's my opinion. I really haven't seen much of a speed difference between mod_php and mod_perl, I happen to love Perl's OO setup (10000000x better than C++) and although it causes me headaches from time to time, Perl's regexp abilities are far more flexible than PHPs.
Then it's irresponsible of you to be spreading myths about something you admittedly don't understand fully.
Okay, I'll call you on that one. Where am I spreading any myths? I gave my opinion and several reasons behind why I have that opinion. But let's take my original post on a point per point basis and you show me where I'm spreading myths. I don't even think you read the second comment after the first sentence.
- Why learn two languages when one does 99.9% of it without breaking a sweat?
Why indeed? I don't see this as spreading myths; In fact I consider this a fact.- PHP has umpteen number of DB interfaces.
And it still does. Perhaps there are third-party classes which attempt to intgrate them (I even remember doing half of one myself) but no singular DB interface had become the main one when I was playing with PHP. This is a myth?- Perl has DBI. No matter what you talk to it's all DBI and it's fast.
I hope you don't consider this a myth.- Yeah I know about the PHP interpreter but that's just plain old hokey.
This you might construe as a myth but when I played with PHP it was hokey.- Regexps? OO? Parsing? PHP and Perl both have them
More truth.- But really when you think of it you have other things to do too... parsing logs, reformatting, search and replace... things that get done on a daily basis and are beyond the scope of "just the web". Write the module once, write it good and use it in all situations!
I stand by that statement. From what I have read now PHP has a "regular" invocation to do CGI. However it is still not as common nor (IMO) as powerful as Perl. Myths? Disinformation? Hardly. Opinion? Definately.So now... Show me where I'm spreading myths. If you can't, then please retract your statemnt that I'm spreading myths. After all, anything else would be irresponsible.