A while ago now, Sarah commented that one night when she's woken up in the middle of the night, that she'd observed me stop breathing for a while in my sleep. She wanted me to go see the sleep doctors that she'd seen (she was diagnosed with obstructive sleep apnea a couple of years ago). So I eventually packed myself off to the Stanford Sleep Disorders Clinic, which is at Stanford's shiny new outpatient centre in Redwood City. They took a look at me, and declared I had a crowded mouth, and a narrow airway, and asked me to do a sleep study. I did the sleep study in the middle of January. That was "interesting". I had a ton of wires glued to me, and needless to say, I didn't sleep particularly well, but apparently I slept enough for them to be able to diagnose me. A couple of weeks later, I got a letter with the results. I had a Respiratory Disturbance Index of 16.6. The letter from the clinic defined RDI as including "events of 10 seconds or more with cessation of airflow or discernable reduction in airflow associated with arousal or oxygen desaturation of 3% or more". I had one obstructive sleep apnea event, and 119 obstructive hypopnea events during the sleep study. At one point my O₂ saturation dropped to 89%, but it was very briefly. The overall average was 96%. A month ago I did another sleep study, this time while I was hooked up to a CPAP machine, and they fiddled with the pressure. I was fairly exhausted that night, and slept like a log. Based on the results of the second sleep study, I've been prescribed an auto PAP machine with a pressure ranging between 13 to 15 cm of water pressure (whatever that means). I got the machine, a ResMed S8 AutoSet II a week ago last Friday. It's slightly more advanced than the CPAP machine that Sarah uses, in that it'll adjust its pressure within the range it is set to, as it deems necessary throughout the night. It also backs off the pressure when you exhale, like Sarah's does. I'm not particularly thrilled to be sleeping with this thing on my face. The first night I used it, I slept fine. Something like from 10:30pm until 6am. Subsequently, I keep waking up at precisely 3:30am for some reason, and it's hard to get back to sleep with it on, so I take it off. A few nights, some sort of mask leakage alarm has gone off at some random point in the night. I haven't been in any state to try and diagnose what's going on when that happens, so I just take off the mask and turn the whole thing off. I was curious as to whether I'd notice some sort of life-changing difference between using it and not using it, like Sarah does, but so far, I can't say I've noticed any discernable difference. I also haven't gone a night without using it yet. Getting a properly fitting mask was a bit of a challenge. I spent ages at the durable medical equipment supplier trying on different sorts of masks. The one I've currently got still leaves a bit of a red mark across the bridge of my nose. I can take it back in the first 30 days, and get refitted, so I might still be doing that.

Jacob is very interested in how things work. He s 3.5 years old, and into everything. He loves to look at propane tanks, as the pressure meter, and open the lids on top to see the vent underneath. Last night, I showed him our electric meter and the spinning disc inside it. And, more importantly, last night I introduced him to the Linux command line interface, which I called the black screen. Now, Jacob can t read yet, though he does know his letters. He had a lot of fun sort of exploring the system. I ran cat , which will simply let him bash on the keyboard, and whenever he presses Enter, will echo what he typed back at him. I taught him how to hold Shift and press a number key to get a fun symbol. His favorite is the hat above the 6. Then I ran tr a-z A-Z for him, and he got to watch the computer convert every lowercase letter into an uppercase letter. Despite the fact that Jacob enjoys watching Youtube videos of trains and even a bit of Railroad Tycoon 3 with me, this was some pure exploration that he loves. Sometimes he d say, Dad, what will this key do? Sometimes I didn t know; some media keys did nothing, and some other keys caused weird things to appear. My keyboard has back and forward buttons designed to use with a web browser. He almost squealed with delight when he pressed the forward button and noticed it printed lots of ^@^@^@ characters on the screen when he held it down. DAD! It makes LOTS of little hats! And what is that other thing? (The at-sign). I ve decided it s time to build a computer for Jacob. I have an old Sempron motherboard lying around, and an old 9 black-and-white VGA CRT that s pretty much indestructible, plus an old case or two. So it will cost nothing. This evening, Jacob will help me find the parts, and then he can help me assemble them all. (This should be interesting.) Then I ll install Debian while he sleeps, and by tomorrow he should be able to run cat all by himself. I think that, within a few days, he can probably remember how to log himself in and fire up a program or two without help. I m looking for suggestions for text-mode games appropriate to a 3-year-old. So far, I ve found worm from bsdgames that looks good. It doesn t require him to have quick reflexes or to read anything, and I think he ll pick up using the arrow keys to move it just fine. I think that tetris is probably still a bit much, but maybe after he s had enough of worm he would enjoy trying it. I was asked on Twitter why I ll be using the command line for him. There are a few reasons. One is that it will actually be usable on the 9 screen, but another one is that it will expose the computer at a different level than a GUI would. He will inevitably learn about GUIs, but learning about a CLI isn t inevitable. He won t have to master coordination with a mouse right away, and there s pretty much no way he can screw it up. (No, I won t be giving him root yet!) Finally, it s new and different to him, so he s interested in it right now. My first computer was a TRS-80 Color Computer (CoCo) II. Its primary interface, a BASIC interpreter, I guess counts as a command-line interface. I remember learning how to use that, and later DOS on a PC. Some of the games and software back then had no documentation and crashed often. Part of the fun, the challenge, and sometimes the frustration, was figuring out just what a program was supposed to do and how to use it. It will be fun to see what Jacob figures out.

The recordings for Linux Conf Australia 2010, held this year in Wellington, are finally online. The recordings include a video of my keynote on Antifeatures. I was deeply honored to be invited to give a keynote at LCA and, as a result, felt more pressure than usual to put together something that was novel, relevant and entertaining and that spoke to core issues and problems facing free software. Although it's always hard for me to watch myself speaking, I've made it through the video and am reasonably happy with the result. Although perhaps it's a minor distinction, I think this lecture is probably the best talk I've given given to date! I hope to give the talk again so, as always, I welcome comments and feedback. If you'd like to watch it, the talk is available in a number of free and non-free formats:

• Video in Ogg Theora -- Should "just work" in new versions of Firefox
• Audio in Ogg Vorbis
• New Zealand Mirror with media in Flash, Theora, Vorbis, and MP4/MP3 versions

On Wednesday, I went to a meeting of the Business Initiative for North Somerset for Cooperatives-SW (our regional cooperative cooperative). It was the first time anyone from the cooperative and mutual sector was present.

Conference Bank of England The first speaker was Geoff Harding from the Bank of England, who talked through topics in their agents summary and related news. One interesting graph showed a steep rise in the percentage of household income being saved. Answers to questions suggested that more of that goes to mutuals and building societies, but they find it difficult to be competitive while the banks are keen to increase their balances. There was mention of employment hoarding businesses short-time working, redeploying or shutting down temporarily to keep trained workers under contract, rather than make them redundant and rehire later. People from both the Federation of Small Businesses and the Hoteliers Association made strong comments about the banks claiming to government that they are willing to lend, but still offering deeply unattractive depth-of-recession rates and terms. If the regional agents get details of such cases, they pass them to the central bank. South West Regional Development Agency The second main speaker was Ann O Driscoll, who covers business development for the West of England (what many people call CUBA Councils that Used to Be Avon). She introduced their four strategic priorities:-

1. Low Carbon Economy apparenly our region has good wind, wave and solar experience. However, Vestas were mentioned and I know that when Vestas closed the UK s only wind turbine blade factories in August 2009, the RDAs were criticised for not acting against the subsidy-chasing, socially irresponsible conduct of Vestas and related companies continue to worry workers. If Vestas is one of the praised companies, I wonder whether we re attracting sustainable work to the region. On a related note, North Somerset Council and NS Enterprise Agency are organising a Climate Change forum on 1st April, but it s at Cadbury House Hotel, which is awkward to get to except by car: no footpath to the door, a mile-and-a-half walk along a busy road from a train station, bad roads for biking, wheelbending speedhumps on the drive, I can t remember if there is bicycle parking and its website doesn t say
2. Successful Businesses SWRDA funds our rather poor Business Link service. Does someone in the South West have some good news about Business Link? If so, please leave a comment on this article.
3. Prosperous Places intervention in areas like south Bristol or central Weston.
4. United Approach co-ordinating with other regional groups.

The main activities introduced were:

• Area Action Forces eight of these facilitate the closure of branches by large private-sector employers, gathering the various government departments and agencies together to help find the workers other jobs or fill out social security application forms. It probably helps, but I was surprised there wasn t any example of a regionally-owned phoenix company arising from a branch closure to continue the service was mentioned.
• Talent Retention Project finding new employment for unemployed specialists in their own sector in this region. New startups were mentioned briefly. Not one mention of helping those specialists to co-own existing businesses.

The questions were fascinating, except for mine. The best one was probably about the forthcoming election and the Conservatives pledge to shut down the RDAs and Business Links. The answer was that much of the work will still need to be done somehow, so it s more a question of who will do it, rather than what the name on the door says. So I don t think axing RDAs is going to achieve more than shuffling people between organisations. When allowed to ask a question, I got too excited and ranted a bit about how the Co-operative Group s co-operative enterprise hub is doing work that Business Link should have been funding, but the RDA doesn t understand social enterprise and treats it as a ghetto service. I ll try to take that up in a more coherent form later. Overview I think Cooperatives-SW were invited to the North Somerset Initiative largely because of pressure from software.coop for co-ops to be represented better in the Local Strategic Partnership, which has treated us badly. NSI holds one of the three business places on the partnership board, with the other two being held by NSEA and Bristol International Airport. I think it s a bit off that a private company and an enterprise agency are both represented by other groups and also have their own board seats while co-ops don t even have a collective seat, so that pressure for a representative organisation for co-operatives and mutuals to have a board place (in line with national government guidance) should continue, useful though the NSI meetings seem to be. The other thing which would really help is some funding for co-operative business development specialists to work in North Somerset at strategic tasks like this, instead of it being left to ordinary workers from other sectors. I don t know where that funding will come from and until then, I ll continue to try my best. We need to make sure that local strategy at least does no harm to the sector.

The most common criticism of the Anti-Counterfeiting Trade Agreement (ACTA) is the lack of transparency. Before the nations disclose the terms of the agreement under negotiation, we are unable to gain an idea of the big picture, let alone voice our opinions and push for changes. Our politicians don t want us to know. We rely on leaked documents for our information. This is backwards in a world where a state should represent its people. This smells foul to me. There are undoubtedly some good reasons for the treaty, and if we can contain worldwide, large-scale trade of counterfeited goods and medicine, then that would be a net benefit to us all. However, we must not allow certain governments to succomb to the pressure of (commercially-motivated) lobbyists, to extend that pressure onto other nations using trade as a means of pressure, and to slash our freedom as if it were an inconvenient obstacle in their way. Only if the terms under negotiation become publicly available, and the public is given a voice, then we can help our governments in entering an agreement that is in the interest of its people, rather than a threat to us. It is hardly surprising that total capitalist nation USA are the strongest opponents of transparency, because the public might delay or even prevent the treaty. I was also not surprised to see South Korea and Germany in the list of supporters of secrecy either. It is interesting to see that the leaders of Singapore, Belgium, Portugal, and Denmark also seem to believe that these negotiations should be withheld from the public. Does anyone know about Switzerland? I tip my hat to New Zealand, Canada, Australia, Netherlands, Sweden, Finland, Ireland, Hungary, Poland, Estonia, and Austria for their support of transparency.

It s hard to do a healthy diet outside the home? Whereas many of the activities carried out. Try some tips refer to following a healthy diet that you can do outside. re Dieting to reduce consumption of fats, carbohydrates or sugar? That does not mean you can not eat well. With a few tricks and cunning look of food, you can even a good meal in a restaurant also order food from fast-food restaurant. Try it voyeur tips from DASH, Dietary Approaches to Stop Hypertension. With these healthy tips you can still eat well and avoid high blood pressure or high cholesterol levels. Well, try telling refer to the following tips: 1. Avoid foods with saturated fats and cholesterol High
But avoid foods that contain saturated fatty acids and also high yan foods contain cholesterol. You can avoid these foods but still give priority to taste, a variety of menus to choose from, even a favorite. If you re eating out make sure the following things:
- Make sure your food is cooked using olive oil instead of butter or
fat if the dish was a stir-fried or something.
- Ask for salad dressing or salad dressings are low in fat.
- If mkan meat or chicken, remove the parts that contain fat such as chicken skin.
- Choose foods with dimaska burned, boiled, or baked. In addition to not using oil, usually healthier. 2. Watchful Against Salt
Another thing to note that this works DASH diet is salt. Because salt can raise your blood pressure, while salt is often used in a variety of restaurants to make food more delicious. You still can control the salt in your food when eating out by doing:
- Ask the waiter to not put salt or MSG in your food.
- Beware of any food that a high salt content such as pickles, soy sauce, broth, bacon, and others.
- Keep the salt from your desk, because usually you will reflexively add salt to the food.
- Reduce the use of mustard, ketchup, pickles, and other Condiment a high salt content.
- Choose fruits or vegetables as the opening menu. 3. Avoid foods with a portion of
But avoid foods with large portions. In addition you will feel
unfortunately if the foods are not consumed, you will feel sick if you eat too much excess. We recommend that you order enough food. Or if that portion is too big, shared with friends is much better. 4. Always Instill Healthy Living Patterns in the Mind
More and more people realize how important a healthy life, making a lot of restaurants started to state that low-fat or rich in antioxidants to the food they sell. Actually do not stop until the food alone, you
also have to think about drinks or dessert healthy what happens to the balance. For example:
- Choose a drink that does not cause side effects, such as mineral water, fruit juice, or herbal tea.
- Expand vegetables and fruits as well as the opening menu to avoid overeating at the main menu.
- If you decide to eat a salad, choose low-fat sauce or put the sauce on the plate edge so that its use is not excessive.
- Avoid mouthwashes that contain high fat like cheese cake. We recommend that you choose desserts such as fruit, sorbet, or fruit jelly. 5. Order careful in Resto Fast Food
Fast-food restaurant is the most dangerous enemy to your diet. But if you are careful, you can still enjoy fast food without the fear of cholesterol or high blood pressure soared and certainly does not ruin your diet program. Here are some tips if your food in the restaurant inginmemesan fast food:
- Take your time choosing foods, read the content carefully to what
contained in one serving. And do not be shy to ask the waiter about
Andapesan food.
- Combine your foods such as grilled chicken with whole wheat and yogurt drinks or low-fat milk.
- Do not order more servings.
- Be aware of and avoid salad dressings containing Condiment bleak high salt soy sauce, ketchup, and pickles.
- To drink mineral water should choose, even if others want to order to avoid fizzy drinks.

The main sources of information used when hiring someone are their CV, the interview, and references. CV The CV is written by the applicant or sometimes for the applicant. Naturally it says only good things, if a CV notes no skill in a particular area then it may be used to exclude an employee from consideration. But the trend is towards including a reference to anything that you touch, so someone who lists DBA experience may merely have done a couple of CREATE TABLE operations. Interview The interview is a good test of people skills but is often of little value in assessing technical skills. The interviewer asks questions such as do you know technology X and the applicant says I know that really well . If the company is hiring another person with similar skills to current employees then they can have their current employees sit in on the interview and ask difficult technical questions, but for unknown reasons managers often don t take that option and get no advice from their technical people. Also if the company is hiring someone with specialised skills (EG they are about to implement a new application and want to hire their first employee to work on it) then it may be impossible for them to assess the technical merit of answers. Probably the best use of the interview is to match answers with the CV, if the applicant doesn t appear to know the contents of their own CV then they should be rejected. The biggest problem with interviews is when the questions are all of the form do you know X . Someone who really knows it will say yes as will someone who doesn t know enough to realise the limits of their knowledge and such ignorant people vastly outnumber the skillful people. The real problem is that the people who are moderately skillful will lose out. If someone asks me about my MySQL skills I will tell them that I m not really good at it. Sure I ve run replicated servers with tens of thousands of users running 24*7, but that doesn t mean I m really good at it probably most people who will claim to be great at MySQL without qualification would have less experience than me. References Reference checks rely on an unknown person saying good things about the applicant. For starters there is the issue of the number of references which may not be representative of their employment history EG the applicant could use as a reference the one manager who didn t sack them. The next issue is that there is little incentive for the referee to be honest, most people are aware of instances where someone once worked for a friend and can rely on good references for the rest of their career. If a reference is inaccurate then there is no realistic opportunity for redress. Finally every reference check that I am aware of (checks where I have been the referee or the applicant) has involved the applicant giving the phone number of the referee to the hiring manager! The phone could be owned by a friend or relative of the applicant, so logically a good reference that is based on trusting the applicant to supply the phone number only proves that the applicant is either good or really bad. To make a reference check prove something the recruiter would at a minimum have to phone the number listed in the white-pages for the corporation that used to employ the applicant, asks to speak to the manager of the relevant department, and then gets a reference. Calling a mobile phone number that is supplied by the applicant (which seems to be the standard practice) is essentially trusting the applicant and trust is the root cause of most security problems! Really most of this ends up as trusting the applicant to provide honest evidence that they are trustworthy and believing that the applicant s technical knowledge is good enough to be correct when they say that their technical knowledge is good. It can fail spectacularly when someone isn t trustworthy enough to provide honest evidence of their integrity or when someone doesn t have the skills needed to know that their skills are lacking. As an aside, even if the reference is given accurately and in good faith it may still be misinterpreted. The fact that telephone references are exclusively relied on exacerbates this problem. Ideally references would be in writing with some way of proving their authenticity (maybe using phone verification of the accuracy of the written document). Solutions So how can we solve this? Some people believe that career based social networking software will solve the problems, but as usual I think that software doesn t magically solve human problems. The first challenge when trying to use social networking to solve the problem is to find someone on your friends list who has relevant knowledge, this may be viable in a small industry (EG when someone from bank A applies for work as bank B in the same city). The next issue is that of false friends . I m sure that I m not the only person who has been pressured to add people as friends on social networking sites, the non-computer social interactions really don t prepare people for saying no you are not my friend (apart from high-school I guess). With professional social networking sites there are further issues, if you are working on a client site and a manager demands that they be listed as one of your friends then what are you going to do? So it seems to me that the social networking sites are at best a helper for the gossip network. If you think that a friend of a friend from a social networking site might be able to help you then you first ask your friend if the person in question is really a friend, and if so are they one of the shifty pseudo-friends you only hang out with because their company pays good money. But the problem with the gossip network is that it s mostly secret and is therefore subject to settling vendettas, I ve heard of senior managers going out of their way to spread false stories about former employees to settle scores. The best solution I can think of is for someone who has a reputation to publicly stake it on the accuracy of their references. If I m going to give a reference then I would be happy to do so via a GPG signed email or a blog post. This doesn t mean that my references will always be correct, but it would show that I try to give good references.

I received a surprising 13 responses to my previous post, which was certainly more than I expected and is one reason it's taken me a few days to follow up on it. (How do you pick someone from a group of 13 people based on just a paragraph or two? Clearly I'd like for someone to help all of these people get involved in Debian, but to do so solely by myself would be making a commitment that I just don't have time to come through on. So, it ends up being quite arbitrary. I pick who I think I'd most like working with and could make the most out of the opportunity, and even that is an arbitrary judgement based on very little.) One question asked by one of the people who emailed me was, "Why did you ask for someone who isn't involved in Debian already and who doesn't necessarily have the technical skills needed?" The answer to this question has several facets. For one, people already involved in a free software project tend to be busy people. The workload in projects tends to be concentrated in few hands, and many of those people who are already involved in a project don't need or want any more work. So, asking for someone not already involved in Debian increases the pool of people who might respond to such a request and actually be able to follow up on it. While this a valid reason, it still doesn't explain why I didn't just say, "it's okay if you're not already involved in Debian or don't know python" and not state a preference as to the skill level of the person who would respond to such a request. I did, however, have a specific reason for stating my preference. I asked specifically for someone who wasn't already involved in Debian and who didn't necessarily know python or consider themselves a competent programmer because I wanted to encourage people who don't consider themselves to already know enough to be a useful comaintainer to contact me. I've picked up a lot from following Geek Feminism on what sort of language turns minority groups like women away, and I wanted to ask in such a way that it didn't turn away people who aren't good at self-promotion or who are less sure of their skills, or who don't yet have the skills, men and women alike. Even I still sometimes internally question my own competence as a programmer, and my self-confidence has increased over the past few years. (For the curious, the responses I received were, at my guess, 85% male, 15% female. Whether that's a success or not depends on the demographics of those who read the post, but it is better than the ~98% male involvement in the FLOSS world altogether.) And I do think it's more of a contribution to the project to help someone new get involved than to try to convince someone who's already overcome the barrier to entry to take on some more work. We'll see how it turns out in the end. I have high hopes. (No pressure, soon-to-be-selected mentee.)

I ve been having some cooling problems with my Thinkpad recently. It s an old model T41p which is outside the service period so IBM/Lenovo won t help me (at least not unless I give them more money). If I run it for a few minutes at maximum CPU when the ambient temperature is about 20C then it gets to 90C, apparently 93C is the temperature at which it turns itself off, so obviously I need to do something to keep it cool. On the really hot days of summer my air-conditioners can t keep any part of my house below 30C, so on such days I can t do any compiles on my Thinkpad or watch videos. My Thinkpad seems to idle at a temperature that is about 35C higher than the ambient temperature. At this rate the system could get close to it s maximum temperature on a 45C day by just idling! Not that I plan to have a warm Thinkpad on my lap if I ever happen to be outside on such a hot day. I suspect that a large part of the problem is the dust that has accumulated inside the machine. I asked about this on the LUV mailing list and Andrew Chalmers suggested The Chaos Manor review of taking a Thinkpad T41p apart [1]. The Chaos Manor guy wanted to replace his CPU with a faster one so he had to get access to all the same bits. I followed the instructions until I got to the stage of prying the heatsink off the video chip. I figured that I will never be able to attach it as well as it is currently attached so I will get different cooling problems if I go any further. Taking it apart to that degree was a moderate amount of work, getting the keyboard bezel off was the most difficult part, and taking the palm-rest off required removing bits of plastic that were stuck in place to cover screw holes which will probably fall off in a week or two. Probably everyone who owns a T41p that they regularly use has a similar problem to me as all such machines have been out of support long enough to have accumulated a lot of dust. So I recommend that other T41p owners not disassemble their machine as much as I did, but instead go for my plan B which is to blow compressed air through the CPU cooling system. Doing this merely requires removing the keyboard. One tip that I have heard is that you should hold the fan in place when blowing compressed air as the pressure of the air may spin the fan fast enough to generate enough electricity to damage the motherboard or damage it s bearings. But you might want to wait until I ve got my Thinkpad done before you blow compressed air through yours, it could very well be destroyed. The other option is to try and use software to control the temperature. Patricia Fraser suggested controlling the fan speed [2]. I did some experiments and found that increasing the fan speed dramatically slowed the increase in the temperature. A 10 minute build is almost certain to bring the temperature to dangerous levels in a default configuration, but it seems that if I set the fan to maximum speed before starting the build then I can mitigate this problem. Most programs that I work on will compile in significantly less than 10 minutes. Another possibility that occurred to me is that of limiting the speed of the system. It seems that ACPI has support for reducing the CPU frequency when the temperature rises too much, but Matthew Garrett has pointed out that this effectively increases the amount of energy used (and heat dissipated) for any given quantity of work [3]. So what I want to do is to cause the CPU to idle periodically when it gets too hot. I ve been idly considering writing a program that uses SIGSTOP and SIGCONT to control the operation of programs such as make, or writing a program that creates a new pty (like script) and pauses the output whenever the CPU gets too hot. Of course the easy option would be to figure out how to set the threshold temperature where the CPU speed is limited. Which is made slightly more complicated by my choice of kernel 2.6.30 for Ext4 support. Now the kernel doesn t work with my acpid and I m starting to get forced into an upgrade to Debian/Testing. Does anyone have any ideas?

• [1] http://www.chaosmanorreviews.com/open_archives/sl_20070205.php
• [2] http://www.thinkwiki.org/wiki/How_to_control_fan_speed
• [3] http://mjg59.livejournal.com/88608.html

There s a lot of responsibility on the shoulders of system administrators. Unless you re one, it s probably hard to grasp the full weight of it. This week has been full of reminders for me. This afternoon, shortly after lunch, I got word that people were having trouble with phones. A few minutes of testing showed that calls within our city were working fine, but it was completely impossible to place or receive long-distance calls. A little while later, a local newspaper s website indicated that numerous cities over a multi-county region, all served by the CenturyLink local telephone company, were out of service in this manner. I figure that represents hundreds of square miles, or a patch of rural Kansas roughly the size of Los Angeles. Adding to the problem was the fact that emergency 911 services are accessed via these long-distance lines that were down. For roughly three hours, 911 was completely down across this entire area. What s more, many cellphone towers and Internet access options were also taken down, since they feed from these same lines. This adds up to a situation that could very easily cost lives due to delayed response of emergency medical, fire, or police services. In the end, the problem was traced to a bad controller card on a Titan 5500 owned by AT&T. Now, here s the system administration angle: If you worked for the phone company and had to troubleshoot a problem that you knew had taken down emergency services for thousands of people, what kind of pressure would you be feeling? Would you be able to keep your cool? I m glad that I don t have that kind of job. I also wouldn t like to be the engineer (or, more likely, accountant) that decided that they didn t need any more redundancy to provide good service to the area. Especially considering this is the second time in the last year or two this has happened. But, ironically, yesterday I signed a purchase order for a new Asterisk PBX (corporate phone) server. When selecting a machine for that task, I am always completely conscious of the responsibility on my shoulders: several hundred employees rely on the machine that is ultimately my responsibility to select. Our own access to 911 would be cut if the machine were to go down. I never forget that the correct operation of the systems that our team sets up and deploys could help save someone s life, and that a malfunction could cost the company dearly in terms of revenue, productivity, image or worse. Nearly four years ago, we switched from an analog PBX, with outsourced support, to a digital VOIP system running Asterisk. Note that we use VOIP in-house, but do not use it externally. Anyhow, I can not say that the Asterisk PBX has been 100% perfect; I doubt that this could be honestly said of any PBX of any complexity. I can say, though, that it saved us well over $100,000 AND has proven far more reliable than the system it replaced. Outages are exceptionally rare and brief now. Plus we have internal expertise to fix it, rather than having to wait for a technician to be dispatched from a city 2 hours away to fix anything. I know I don t have the resources to build a perfect PBX that will never go down (if such a thing is even possible), but I take my responsibility regarding a reliable PBX extremely seriously. We used to have a frequent problem: someone would call 911, then hang up. We suspected this was often on accident maybe people hit 9 for an outside line, then misdialed their number. In any case, 911 dispatch would then call our main office, saying they got a hangup. A person or team would then go across our entire campus making sure nobody was in distress that nobody had managed to dial, then passed out, for instance. With Asterisk, I was able to help this situation. Whenever somebody calls 911 now, two emails are generated: the first contains details about the call, such as the extension number that called and the duration of the call. This goes to all people that are likely to receive a callback from 911. It may not always pinpoint the source (as with somebody using a wireless phone), but almost every time will give us a very good idea where the call came from. The second email is a recording of the call, and serves as an additional clue, but goes to fewer people. I am aware that email isn t a perfect medium, but: it let us make a dramatic (albeit imperfect) solution to a problem that very few institutions our size are able to address nearly so well. There s a lot of weight on our shoulders: keeping the accounting system up, the Internet links up, the web store or the sales phone lines, the shipping systems or the document archives up. These things going down can spell deep trouble in many ways. And sometimes the systems we maintain might save a life. Such as this morning, when someone was feeling symptoms of a heart attack, used our phones to call a colleague for help, that person called 911, and an ambulance was dispatched. I know the system worked exactly as it should, because I had two familiar emails from Asterisk in my mailbox this morning when I got to work.

I ve just bought a Packard Bell OneTwo (M3700), a 600 Euros all-in-one computer with a 20 multipoint touch screen (there are bigger models with 23 touch screen, wifi and some other options). This machine will be used to run OpenBravoPOS, a free (libre) point of sale software. So far, I think this machine is just perfect for the job. Getting it to run smoothly under Linux is not a walk in the park, however. There are some quirks and some assembly is required, but once you re done (that takes a couple of hours at most once you ve got all the info, which you have if you re reading this) this machine is just great. It s fast, with a 2.1 GHz Pentium Dual-Core (T4300) CPU, 4 GB of RAM, an Intel GM45 GPU with up to 256 MB of shared RAM, gigabit networking, a fast 320 GB SATA disk and a combo DVD-drive (not a slot-in, too bad). The screen is nice, and the touchscreen is incredibly smooth, precise and sensitive. The sound is good, the webcam is great and it works out of the box, too! Update: added a note about the card reader. Before you go Enter the BIOS and bump the amount of memory allocated to the GPU to 256 MB. By default, the machine ships with only 64 MB allocated to the GPU, which is low and ridiculous considering it is equipped with 4 GB Installing Debian Forget about installing Lenny with debian-installer on this machine. The standard installer with its 2.6.26 kernel doesn t support the network interface properly. Upgraded installer images with 2.6.28 or 2.6.30 kernels end up locking the machine solid before the first installer screen. Your best friend: System Rescue CD. Your other best friend: debootstrap. Before rebooting, install the 2.6.30 kernel from backports.org. It works like a charm, even if the 2.6.30 on the upgraded installer locked up solid. Go figure :) While you re at it, install X from Testing. You need a recent enough version of the intel driver that will support the GM45 chip. Configuring X This is the first and the biggest quirk on this machine. The LCD is actually wired up to both the VGA and the LVDS outputs on the graphic card, and advertises different resolutions on both. The native resolution (1600 900 on this model) is only advertised on the LVDS output. While fiddling with X, it becomes obvious that the VGA output is used as the boot video device. If you disable the output in X with xrandr, you loose the text consoles. My un(?)educated guess is that this setup allowed them to use a standard desktop PC BIOS instead of using a more expensive laptop BIOS. I may be wrong, but that s pretty much the only thing that makes sense to me. Anyway. If you want X to work properly, you ll have to tell it to ignore the VGA output entirely.

Section "Device"
 Identifier  "Intel X4500"
 Option  "Monitor-LVDS"  "Panel on LVDS"
 Option  "Monitor-VGA"  "Panel on VGA"
EndSection
Section "Monitor"
 Identifier  "Panel on LVDS"
EndSection
Section "Monitor"
 Identifier  "Panel on VGA"
 # The LCD panel is wired up on both VGA and LVDS
 # Ignore the VGA output as far as X is concerned
 Option  "Ignore"  "True"
EndSection

If you don t tell X to ignore the VGA output, you ll end up with a mirror setup and your desktop will use the smallest size so as to fit on both monitors. It isn t pretty, it s plain silly and we want those 20 used fully, dammit! See the full xorg.conf. Touch screen The touch screen is an infrared multipoint touch screen from Quanta. No kernel driver is needed, only an input driver for X is required. Start by adding an udev rule like this one:

SUBSYSTEM=="usb", ATTRS idVendor =="0408", ATTRS idProduct =="3000", SYMLINK+="usb/quanta_touch"

The touch screen will now appear as /dev/usb/quanta_touch, which is more handy and stable than /dev/usb/hiddevN. Grab xf86-input-hidtouch from HidTouch Suite on SF.net, and apply this patch. The aim of the patch is to ignore anything but the first reported pressure point. The touch screen is a multipoint touch screen and as such can report 2 or 3 (not sure) pressure points at the same time. The driver can t handle that yet. The patch also fixes a bad comment and an API difference with newer X versions. Build and install the driver, then edit xorg.conf:

Section "InputDevice"
 Identifier  "Optical Touch Screen"
 Driver  "hidtouch"
 Option  "SendCoreEvents"  "true"
 Option  "ReportingMode"  "Raw"
 Option  "Device"  "/dev/usb/quanta_touch"
 Option  "PacketCount"  "13"
 Option  "OpcodePressure"  "852034"
 Option  "OpcodeX"  "65584"
 Option  "OpcodeY"  "65585"
 Option  "CalibrationModel"  "1"
 Option  "CornerTopLeftX"  "0"
 Option  "CornerTopLeftY"  "0"
 Option  "CornerTopRightX"  "1600"
 Option  "CornerTopRightY"  "0"
 Option  "CornerBottomLeftX"  "0"
 Option  "CornerBottomLeftY"  "900"
 Option  "CornerBottomRightX"  "1600"
 Option  "CornerBottomRightY"  "900"
 Option  "CornerScreenWidth"  "1600"
 Option  "CornerScreenHeight"  "900"
EndSection

There you are. Working touch screen! Credit: the above touch screen setup instructions, including the patch (which I reworked slightly ) were taken from this post on the Ubuntu-fr.org forum. The instructions cover the Packard Bell Viseo 200T touch screen, which is identical to what s used on the OneTwo. If you re looking for a 20 touch screen, go for it; at 200 Euros it s a good deal. Sound The Realtek ALC268 codec as used in the OneTwo isn t properly supported yet, however using model=acer-aspire works for the integrated speakers and the headphone jack. Line out and the integrated microphone do not work. Webcam The webcam is a UVC webcam and the image quality is stunning. I m seriously considering stealing that webcam to replace the iSight in my MacBook Pro. It works out of the box without any firmware. Quite a good surprise :) Flash card reader The integrated flash card reader also works out of the box, for the card formats supported by Linux.

I usally find blog rants useless, but sometimes something is just so annoying one is sufficiently inspired. Today I went with my parents to buy them a Tivo at Harvey Norman, Norwest, Castle Hill, NSW, Australia. I am a big Tivo fan; the interface is good and it "just works". I don't mind paying for (or in this recommending paying for) good products. After selecting the Tivo model, I asked for a HDMI cable. The salesman made a series of questions about what sort of HD TV it was being plugged into; I quickly sensed this as a probe to see what sort of suckers we were, and requested just a "normal" cable. At this point, he insisted on a $130 (you guessed it) Monster cable, and had the audacity to say that we didn't need one of the really expensive cables because our TV wasn't good enough! I openly expressed my concern, but the annoying high-pressure sales pitch had just begun. The amount of, frankly, crap that he spewed about 4-bit this, 10-bit that, legislating of labels, DA signal levels, mythical customers who regretted buying the cheap cables and who knows what else was to the point of being comical if it weren't so insistent and said with such seeming authority. There is only one thing that matters - if the cable has passed the functional requirements for being certified to have the distinctive HDMI logo plastered on it. From the HDMI FAQ:

Q. What testing is required? Prior to mass producing or distributing any Licensed Product or component that claims compliance with the HDMI Specification (or allowing someone else to do such activities), each Adopter must test a representative sample for HDMI compliance. First, the Adopter must self test as specified in the then-current HDMI Compliance Test Specification. The HDMI Compliance Test Specification provides a suite of testing procedures, and establishes certain minimum requirements specifying how each HDMI Adopter should test Licensed Products for conformance to the HDMI Specification.

Now, I can understand that if you buy any old HDMI cable off Ebay for $1, it may be a knock-off that uses the HDMI logo illegally. But there is no way that the certified $50 Philips cable (still very over-priced, but at least not insane, and discounted to $35) performs any differently to some overpriced Monster model certified to exactly the same standard. The thing that annoyed me most was his analogy to buying a tyre. He stated that "if you walked up to a tyre salesman and I said don't want the Pirelli's, just put the cheap-o tires on my Ferrari" I'd be insane, and thus by extension of that logic I was insane for not buying a Monster cable for my great new Tivo. This analogy is completely flawed and really just dishonest. A Ferrari is much more powerful and goes much faster than a standard car. It is plausible it needs a better engineered tyre to perform adequately given the additional stresses it undergoes. A Tivo doesn't put out any more or any less bits than any other HDMI certified equipment, no matter what you do. If the cable is certified as getting all the bits to the other end under whatever environmental conditions specified by the HDMI people, then it's going to work for the 99% of people with normal requirements. Nobody wants to make a significant investment in a piece of audio-visual equipment and feel they are getting something that isn't optimal. Harvey Norman's use of this understandable consumer sentiment to sell ridiculously over-priced cables that do nothing is extremely disappointing. I'm sure the commissions on these things encourage this behaviour, so it is useless expecting the retailer or individual sales assistant to change their policy to reccommend reasonably priced cables. However, it is really Tivo and other manufactuers who get the raw end of this deal; a $130 cable is over 20% of the price the actual Tivo! That is surely affecting people's purchasing decisions. If Tivo and others included a certified HDMI cable with their device, as they do with component cables, and had "Certified HDMI 1.3 cable included" plastered on the box, it would be a harder sell to explain why the manufactuer would bother shipping a certified cable that is supposedly insufficient, and consumers would hopefully avoid the very distasteful high-pressure theatrics I was subjected to today.

This evening I tested some Noise Canceling Headphones (as described in my previous post [1]). I first tried the ones on sale at Brookstone [2], they were the on the ear type so there was never a chance that I would buy them but they seemed like good ones to test. I wore them for about 10 minutes while I walked around the store looking at all the electronic stuff that s on sale. I noticed that they were much more effective at filtering low frequencies and regular sounds. So for the Christmas music that was playing the music was mostly filtered just leaving the sound of the singing. Also I was able to talk to the guy who worked there and hear him clearly when the noise canceling was turned on this can be considered a bug or a feature depending on your planned use. When I listened to electric fans the sound of the buffeting air was filtered just leaving the high pitched bearing noise. It is well documented that there is a hissing sound from noise canceling headphones and sometimes a feeling of pressure. I didn t hear any hissing but it did feel a little different when I turned on the noise canceling. After 10 minutes I didn t feel in any way uncomfortable, so I could probably survive an entire flight while wearing such headphones. I can highly recommend the customer service at the Brookstone store in Menlo Park. The guy who was working there was totally helpful, even by US standards his customer service was really good. Sometimes when you make an unusual request (such was wanting to try the merchandise for an extended period of time) the staff aren t particularly enthusiastic, but I had no problems at Brookstone! After Brookstone I went to a Bose store and tried the Quiet Comfort 15 noise canceling headphones [3]. The Bose store conveniently had a device configured to emulate the sound of a jet engine to demonstrate how the QC15 stopped that. I was quite impressed with that. I did feel that the QC15 was a little light for my taste, I would rather have something bigger and heavier with thicker padding to improve the passive resistance to sound. But I expect that many people would like it to be small and light as it s designed for travel. I visited a Sony store a couple of times, but no-one seemed able to serve me. I ll go there again some time when they are less busy. Finally I have to note that I have received a significant number of comments suggesting ear-bud type devices. I suggest that anyone who doesn t mind wearing such things should consider ear-bud type devices. But as I can t stand such things I will continue my search for over-ear headphones. I may end up just buying the Bose QC15, they seem to be good enough and not really expensive.

• [1] http://etbe.coker.com.au/2009/12/03/noise-canceling-headphones/
• [2] http://www.brookstone.com/
• [3] http://www.bose.com/controller?url=/shop_online/headphones/noise_cancelling_headphones/index.jsp

In a comment on my post about Designing Unsafe Cars [1] Noel said If you don t know how to make a surgery, you don t do it. If you don t know how to drive, don t drive. And if you don t know how to use a computer, don t expect anybody fix your disasters, trojans and viruses. Later he advocates using a taxi. Now I agree about surgery apart from corner cases such as medical emergencies in remote places and large-scale disasters. I also agree that it s good to avoid driving if you aren t very good at it (that would be much better than the current fad of sub-standard drivers buying large 4WD vehicles). But I don t think that people who lack computer skills should avoid using computers. When cars were first invented everyone who owned one was either a mechanic or employed one. Driving a car often involved being well out of range of anyone else who might know how to fix it, so either the car owner or their chauffeur had to be able to fix almost any problem. As the car industry evolved the level of mechanical knowledge required to own and operate a car has steadily decreased. I expect that a significant portion of drivers don t know how to top up the oil or radiator water in their car and probably don t know what is the correct pressure for air in their tires. To a large extent I don t think this is a problem, owning a car involves regularly taking it to be serviced where professionals will (or at least should) check every aspect of the car that is likely to fail. If I used my windscreen-washer less frequently I could probably avoid opening the bonnet of the car between scheduled services! When budgeting for car ownership you just have to include regularly spending a few hundred dollars to pay for an expert to find problems and fix them with of course the occasional large expense for when something big breaks. When the computer industry matures I expect that the same practice will occur. Most people will buy computers and plan to spend small amounts of money regularly to pay people to maintain it. Currently most older people seem to plan to have a young relative take care of their PC for them essentially free mechanic services. The quality of such work will vary of course, and poorly designed OSs that are vulnerable to attack may require more support than can be provided for free. Due to deficiencies in city design it is almost essential to drive a car in most parts of the US and Australia as opposed to countries such as the Netherlands where you can survive quite well without ever driving. When a service is essential it has to be usable by people who have little skill in that area. It would be good if driving wasn t necessary, I would be happy if I never drove a car again. The need to use computers however will continue to increase. So we need to make them more available to users and to support users who can t disinfect computers etc. The only skill requirements for using a computer should be the ability to use a keyboard and a mouse! This requires a new industry in supporting PCs. Geek Squad in the US [2] seems to be the organisation that is most known for this. I expect that there will be multiple companies competing for such work in every region in the near future, just as there are currently many companies competing for the business of servicing cars. We need support for free software from such companies. Maybe existing free software companies such as Red Hat and Canonical can get into this business. One advantage of having such companies supporting software is that they would have a strong commercial incentive to avoid having it break unlike proprietary software vendors who have little incentive to do things right. The next issue is the taxi analogy. Will software as a service with Google subsidising our use of their systems [3] take over any significant part of the market? Of course the car analogy breaks down when it comes to privacy, no-one does anything remotely private in a taxi while lots of secret data is stored on a typical home computer. Google is already doing some impressive security development work which will lead towards low maintenance systems [4] as well as protecting the privacy of the users to the extent that you can trust whoever runs the servers. My parents use their computer for reading email, browsing the web, and some basic wordprocessing and spreadsheet work. The mail is on my IMAP server so all I need is to have some way to store their office documents on a server and they will pretty much have a dataless workstation. Moving their collection of photos and videos of their friends and relatives to a server will be a problem, transferring multiple gigabytes of data on a cheap Australian Internet access plan is a problem.

• [1] http://etbe.coker.com.au/2009/11/24/designing-unsafe-cars/
• [2] http://www.geeksquad.com/
• [3] http://abovethecrowd.com/2009/10/29/google-redefines-disruption-the- less-than-free -business-model/
• [4] http://www.chromium.org/chromium-os/chromiumos-design-docs/security-overview

It is only a few days since my last post about the referendum which is due to happen on the same day as the Presidential elections, but I am forced to make another post because there are lots of incorrect views on the subject.

So let's try take the issues one by one and see what is the problem with every one of them, using reason and the information we have available from more mature democracies than Romania's.

What's the referendum about

The referendum, in this case, is about two issues:

• reducing the number of representatives (deputies and senators)
• transforming the Parliament from a two-chamber Parliament into a one chamber Parliament
  

Information on the subject

For an election such as the referendum (basically asking the population on a subject of national importance) every citizen has the right to be correctly informed about the options of the referendum, what each implies, what are the pros and cons for every option, what problems does the referendum tries to resolve.

There is no information on the subject, no videos, no spots, no fliers, nothing, just biased posters (I'll explain later).

Debate on the subject

In order to have a correct information, a clear public debate which should happen, without the pressure of a presidential campaign at the same time as the debate.


Well, we have no debate, so I guess there is no problem of overlapping (sad, but true), but on the other hand, there is no information on the subject.

Analysis of the options

Now let's analyse the two proposed measures in opposition to the current situation.

1. reducing the number of representatives
• pros
• reducing costs
• minorities have a bigger influence (they can defend their rights - see comments for explanations)
  
• cons
• easier to corrupt (obtaining a corrupt 5% in a 300 seats parliament is easier than in a 500 seats parliament)
  
• minorities have a bigger influence (they are disproportionally powerful, in regard to the population they represent - see comments)
• absence of a representative with a big vote power could allow passing an abusive law (to pass a regular law there is a need of a majority relative to the number of present representatives, not the total number), but, in a numerous parliament, the absence of a person isn't that risky (other colleagues would be present to stop the abusive initiative)
2. one chamber instead of two
   
• pros
  
• faster processing of decisions
• less bureaucratic
  
• cons
  
• in the current system there can be a passive vote (law passes silently if not discussed) which has just one occasion to be caught, while in the current system silent passing is allowed only in one of the chambers, but needs to be discussed in the other
• there is a chance that one chamber might amend/catch abusive initiatives with "two chambers", but with "one chamber" there is one chance only
• more prone to power abuse
  

So, there are pros and cons for all solutions, but now we can make an informed decision and know the risks for each option.

This shouldn't have been taken in haste without any public debate.


I don't want to influence anyone's vote, so I'll abstain from telling my options.

The president has the right to associate his image with one of the options.

OK, let's analyse that.

The law doesn't explicitly forbids this, but there are some recommendations from Venice on fair elections (sorry, I couldn't find the link) which say that in a vote such as the presidential elections there shouldn't be an unfair advantage for one of the candidates. Why is that relevant? Because the current president actually uses the referendum as his campaign and he's speculating people's innate hatred for political figures.

His election material is only comprised of virulent attacks at the representatives or calls to the population to vote in favour of both questions.


Why is that unfair? Because the current president is using his current position (president) as launch ramp for his campaign as a candidate.

OTOH, if the seal of the presidency was used instead his face, the problem wouldn't have been that bad.


Organisational issues

There were various rumours about how the voting will take place. Here is a list of things I heard:

1. there will be a single list for both presidential elections and referendum and there will be a single column for signature to confirm your presence at vote
2. there will be one paper, but two columns for signatures
3. no matter what the list looks like, you'll be given both sets of ballots, but you can annul the one you don't want to vote on

All the variants above are incorrect from a democratic pov, but to different degrees:

1. a single signature covering for either of the vaiants "presidential vote only", "refrendum only", "both" asks for trouble because unused ballots in "only" variants might be added later to the valid votes as if they were expressed by voters; since there is no distinct count for each of the ballots to confront that with signatures, before the counting period one could use unused ballots and vote for you on the issue you didn't want to express an opinion on
   
2. informing on what to do in some cases such as "only" vote is essential to prevent fraud; e.g.: strike through the cell corresponding to the the election you don't want to express a vote on, instead of signing
   
3. giving the ballot unconditionally to everybody, leaving you to decide to annul it or not is abusive, because vote is not compulsory in Romania; more than that, this artificial presence burst (even with void votes) could end up validating the referendum since a 50%+1 presence is needed to pass Constitution modification, as we have here

So, recap:

1. favours fraud by allowing inside people to obtain untraceable/unaccounted ballots
2. preventing fraud isn't of any concern, it seems (and could be achieved)
   
3. forced voting might lead to validation of the referendum because the voting presence is sufficient, even if there are many annuled ballots
   

Vote validation and artificial voter presence

Since validation of a referendum on the changes on the constitution depends on sufficient voter presence (there is some mandatory threshold, but I can't find references now), it is in the interest of people wanting to promote the changes to mobilize people to vote.

By different measures the vote presence at the referendum is artificially increased raising the risk of validation, when people, in fact, wouldn't want to validate it and would, to express neutrality, will be be forced to annul the ballot.

Also, a high presence in the referendum might increase the number of voters for presidency, and the people mobilized this way may have a high chance to be biased in favour of the current president because he associates himself with the violent message against the representatives.

What does it take to implement, if referendum passes

If the referendum passes, the changes aren't immediate. The proposed changes are discussed in the Parliament and a final proposal for the constitution changes is made; after approval of the proposals by the Parliament, the ball goes back to population for final approval.

This means it will take a while to see a changed parliament.

Conclusions

Romania is not a true democracy yet and there are areas where individuals should know what their rights are and not let authorities fool them into buying any argument uncritically.

Romanians must learn their rights so they can't be manipulated whenever somebody wants to trick them into some scheme by knowingly omitting issues and creating insane situations.


Romanians, wake up, learn you have rights, form your own oppinion, as distinct individuals, then we might see a change.

Water supply, in the developed world, is one of those things you just pretty much take for granted. You turn on the tap, and clean, cool, refreshing water comes out. Similarly, when I go to a fire in my shiny fire truck, no matter what time of the day or night, I expect to able to hook up to a hydrant and have a strong, steady supply of water available. This level of reliability is something that we in the IT industry can typically only dream of. Practically 100% reliability over a period of decades, without constant maintenance and tweaking? Not a hope. To even get close to that, we need clusters of fully-redundant servers, fancy database replication techniques, and probably something totally out of left-field like Erlang's ability to reload code on the fly. But how do the water utilities do it? Clusters of fully-redundant high-capacity pumps, fancy pipe re-routing techniques? Or something totally out of left-field like a big water tank and gravity? Where I live, we've got the latter. Thinking about how it probably operates and is managed, I'm blown away by the sheer simplicity and robustness of the whole design, and how it can handle all manner of failures. First off, consider how few components have to be working in order for the water supply to continue for a while after some sort of catastrophic failure. We need:

• Gravity. The water tank is at a high point, and gravity (and the derived force of air pressure) keeps the pipes pressurised. While gravity can, in theory, fail, if it actually does then we've got bigger problems.
• The water tank must be present and with at least some capacity to hold water. Yep, we can blow a hole in the top or side of the water tank and still have some (diminished) capacity to supply water. Try blowing a hole in the side of your data centre and see what happens.
• Piping from the water tank to the water consumption point. I'd say this is the weakest link, but it's a pretty robust link overall (modulo rampaging backhoes) and any other centralised water supply method (other than perhaps teleportation) is going to be at the mercy of a piping failure too.

Note that this list of elements doesn't include any moving parts, or even guaranteed continuous water supply from a dam or other huge supply store. You can lose your feed pump(s), supply lines, or anything else that's on the supply side of the water tank for some period of time and nobody on the consumption side will know or care. Need more resilience to supply-side failure? Just build a bigger tank. This blows my mind, it really does. Need to do pump maintenance? No problem, just make sure that the tank is large enough to service demand over the period of the "outage", and go for it. Can't find a pump supplier to give you a restoration SLA of less than a week? Just make sure you've got a water tank that'll provide for a week's consumption. Basically, any supply-side reliability problem can be solved with "build a bigger tank", and while there's a limit to how big we can make tanks, I'll bet we know a lot more about building huge water tanks to withstand some freaky failure conditions than we do about building pumps that won't fail for 100 years. If you do need more capacity than a single tank can provide, just parallelise -- horizontal scaling of the water supply. Woohoo! Your big water tank also provides cost savings in your other equipment. If you had to pressurise a water supply using pumps, not only would you need your redundant array of very expensive pumps (Hmm, RAVEP-5 sounds like a Doctor Who villain), but those pumps would need to be able to provide your peak consumption flow (toilet breaks during the Super Bowl, probably). I'd imagine that could get mighty expensive, and without providing much benefit for 99% of the time. I see this capacity problem at work all the time. Customers who have the occasional massive traffic spikes need to massively over-provision their average utilisation to successfully service that 1% of the time that they're doing heavy traffic. Yes, I know, cloud computing, horizontal scaling, capacity on demand, yadda yadda yadda. It's not a panacea, and the number of apps that are designed to properly scale horizontally over a large range of traffic volumes is miniscule. My general point, though, is that it when you've got a variable load, it costs a whole lot more to provision systems to supply peak demand than to provision systems that can deal with average demand. A suitably large water tank means you can easily deploy a much smaller capacity feed pump. All you have to do is make sure that when demand exceeds supply, you've got enough water in your tank to cover the difference between the demand and supply over that period. When your peak capacity increases, and is starting to strain your infrastructure, you've got a choice, too: you can upgrade the pump or increase your storage capacity, whichever is cheaper / easier / quicker / provides better kickbacks / whatever. This is all well and good, you say, but computer systems aren't water supplies. There's a lot more moving parts, inputs, and outputs, and those all have to be handled. This is quite true. Water-powered computers are not in high demand. However, I think we could produce some much more reliable systems if we looked for ways we could simplify capacity and redundancy issues, water supply style, instead of layering more and more cruft into our solutions.

---

Ironically, just after I started writing this post (and this gives you an idea of how long it's been sitting in my drafts folder), I saw an article in the RISKS digest about a water supply problem in Santa Cruz, caused by a power outage killing the refill pump for an extended period and resulting in the storage tank running dry. Hey, I never said that it was a foolproof system -- especially when you've got failures of imagination that result in the system that tells people that there's no power relying on the power source it's monitoring being up in order to be able to tell people that there's no power...

Jetstar has announced some new changes to the way they manage their IT infrastructure [1]. Some parts of it are obvious things that people have been doing (or wanting to do) for a long time such as using thin clients with no moving parts (not even cooling fans). But the really interesting part is their plan for managing laptops. They are using a virtual machine image on a flash storage device that can run on any system. So deploying a new system will only require installing the virtual machine software and inserting a storage device. Moving a user s environment to a different system (EG due to hardware failure) will merely require inserting the storage device in a new system. That raises the issue of ownership of the device. It seems that Jetstar are considering using systems that are owned by employees, Stephen Tame said In two years time a laptop should be a condition of employment, and this includes bringing your own laptop . When introducing that I expect there would be some resistance by employees who don t want to spend the money. However
I have previously estimated the costs of running a car [2] which works out to more than $1,650 per year for insurance, registration, basic maintenance, and the interest that would have been received if the car had not been purchased and the money had been invested. Laptops can be purchased for significantly less than $1000 (currently the EeePC 701 is on sale for $219) and can be expected to last for three years or more if you are careful to avoid damage and don t run demanding software. So a job that demands ownership of a laptop is asking for a much smaller financial investment than one which demands ownership of a car. But I expect that many employees won t see it that way. The up-side for employees to bring their own laptops is that they can choose a model that suits their preference. Everyone has preferences regarding the size of keys on a keyboard, the distance that they travel and the pressure required to register a key-press. For desktop machines it s easy to swap keyboards but for laptops there is no such option. Then there s the issue of the trade-off between physical size and weight vs display resolution, personal preferences in this regard will depend to some extent on the body mass and strength of the employee. Now there are a number of security issues related to personal laptop use. Obviously if the laptop has a Trojan-horse program installed then it could sniff any data that goes past on the network. The most trivial case of this could be addressed by running VPN software inside the emulated environment. This would force a Trojan to compromise the virtual environment (EG by modifying the address space) or to compromise the files on disk (insert a Trojan inside the filesystem for the virtual environment). The former would be tricky to get right while the latter would be trivial. Both attack methods have been used in the past and proven to work. This is why many companies prohibit their employees from connecting their own systems to the corporate network. One example of a system that is based around running virtual machines for all desktop operations is the NSA NetTop project [3]. NetTop involves a SE Linux system that runs multiple instances of VMWare for different desktop environments. Each VMWare instance runs at a particular sensitivity level and uses a VPN connection to a back-end network running at the same level. The aim of NetTop is to prevent applications in the different VMWare instances from communicating with each other. The significant difference between a typical NetTop installation and what JetStar might be doing is that NetTop runs on a secure base it s hardware that has been purchased and installed by a military organisation and is run in a secure facility. While personal laptops that are owned by employees can be expected to be infected with viruses and Trojan-horse programs. In the past I have suggested that an employment package for any skilled employee should include some budget for buying things that facilitate the work [4]. It seems to me that a company like JetStar could best achieve their goals by assigning a budget to each new employee to buy a machine for their use. The employee then gets to choose a machine up to that budget which would only be for work purposes. Then when the employee leaves or the machine becomes due for replacement it could be sold at auction. When considering all the costs involved in hiring a new person, spending something less than $1,000 to buy a laptop is nothing. Finally if buying machines for work purposes, you really don t want employees using them for surfing porn. Porn sites tend to be particularly bad for malware distribution. To reduce the incidence of such problems I think that work machines should have their sound hardware disabled and laptops should not be purchased with overly large displays. There is no need to make work machines totally unsuitable for porn surfing (which would also make them less effective for work), but making them less suitable than a $500 budget PC should dramatically reduce the scope of the problem.

• [1] http://www.australianit.news.com.au/story/0,24897,26021336-15306,00.html
• [2] http://etbe.coker.com.au/2008/06/16/cost-owning-car/
• [3] http://en.wikipedia.org/wiki/NetTop
• [4] http://etbe.coker.com.au/2009/02/01/employment-packages/

Once in a while I get this urge to use SELinux on some of the servers I manage, but almost always run in to something that puts me back enough to never finish the project. This time I managed to figure out the last few glitches. In the end, SELinux still has a really steep learning curve, so it's not for the impatient ones. Even though enabling SELinux in Debian has become a lot easier since the first time I tried to get things running, it's still just the tip of the iceberg. In Debian it is just a matter of installing the right packages and running a few commands, but that's just where the troubles start. Most of the howtos focus on single user or shared installations where all users are created locally. Also most howtos fail to mention that you need to relabel files in certain cases. One of the most annoying problem I ran in to was changing all non-system users away from the unconfined_u class. This is of course done like this (found here):

semanage -m -s user_u __default__

The problem here is that it changes the existing user as well and you start to get errors like these:

denied    read   for  pid=32258 comm="bash" name=".profile" dev=dm-5 ino=185474 scontext=user_u:user_r:user_t:s0 tcontext=unconfined_u:object_r:unconfined_home_t:s0 tclass=file

The problem here is that the home directory for the user is still labeled for the wrong class. The fix is to relabel the home. Sadly this is something that you just need to know, it's not explained anywhere. At least I haven't found an explanation anywhere. Another good thing to do before you continue is to change the already existing user to the staff class. Staff class has a bit more relaxed security controls and you get to change the security roles (details here).

semanage login -m -s staff_u myuser
fixfiles relabel /home/myuser

This gets you a semi working setup, next problem usually is that some daemons are denied access to parts of your system. For me, this was postfix trying to access my home directory that was mounted over NFS. For such cases, you should persuade the maker of the module package to update the global policy if it's a common use case. Or you need to create a policy package that allows access to the given files. The process itself is documented in the audit2access manual page. In general you should study the audit2why and audit2allow packages. The former tells you if there is an easier way to fix something (like enable a boolean) and latter will create the required policy lines. Only problem is to compile the policy and load it. The only problem here was to find the right tool and the right lines from the manual. In general the SELinux learning curve is way too steep. It's a system that works pretty well once you learn all the tricks and start to completely understand the toolset. The community should continue working on lowering the bar for new users. There has been some major improvements since I first tried SELinux, so it's the right direction.

Months (even years) of activism, over 140 thousand signatures, and finally another small victory: Brazilian Minister of Justice Mr. Tarso Genro sent a letter [pt-BR] stating that Sen. Azeredo s bill is dangerous, and that the Ministry is working in an alternative (among other things). We had already incited a public hearing that were very fruitful [pt-BR] and might have brought the Ministry to the issue. But don t relax just yet, folks! Right now, working in this alternative , are people with every kind of agenda It s safe to assume that some of them are from the same lobby that pushed Sen. Azeredo first version of the thing. So, yes, this was another victory, but nothing really changed The bill is still approved by the Senate and still has to be reviewed by the Chamber-of-Deputies, and the alternative that will be presented by the Ministry is still under construction. What we accomplished is nothing more than making the Minister aware of the issue So, keep the pressure over your representatives, send messages to the Ministry, stating how you feel about the issue! Let s show them what we want them to do After all, that s why we elected them, in the first place, isn t it? [Published also at Trezentos, in portuguese]