When advogato.org was still cool I signed up to it. It was an interesting research project in skill metrics (determining the rating of people’s coding skills by the votes of others and weighting the votes by the rating of each person), and it was nice to be rated Master soon after I joined. I still use it on occasion for the blog syndication feature (when I find a good blog on Advogato I add it to my Planet installation). When orkut.com was really cool (when every time I had dinner with a group of people someone would ask if they could be an “orkut friend”) I signed up to it. It was interesting for a while but then most people got bored with it. Now there is Facebook and MySpace for social networking for social purposes and LinkedIn.com for business related social networking. I periodically get invited to join those services but have not been interested in any other than LinkedIn. I can’t join LinkedIn because their mail server is regarded as a SPAM source by my mail server but their web server refuses to provide any information on why this is (the rejection was apparently long enough ago that it’s rolled off my logs). The problem with all these services is that I am expected to sign up with each of them and go to a moderate amount of effort in writing up all the data in the various web pages. Writing it is a pain, keeping it up to date is more pain, and dealing with spam in “scrap-book” entries in Orkut is still an annoyance which I don’t want to multiply by four! So far the only step I’ve seen towards addressing this issue is the XFN - XHTML Friends Network [1] project. But that seems to be of fairly limited scope (just referring to the friendship status of people in a <A HREF link). I believe that the requirements for social networking are:

1. Personal data about each person, some of which may only be available to friends or friends of friends.


2. The user owns their own data, has full control over where it’s sent and the ability to request people who receive it to keep some parts of it secret.


3. Ability to send email to friends of friends (determined by the wishes of each friend and FOAF).


4. Ability to get a list of friends of friends.


5. Incorporation of a standard format for CVs (for business social networking).

I think that the only way to go is to have a standard XML format for storing all personal data (including financial, career, and CV data) that can be used on any web site. Then someone who wants to be involved in social networking could create an XML file for a static web server (or multiple files with different content and password protected access), or they could have a server-side script generate an XML file on the fly with a set of data that is appropriate for the reader. The resulting social network would be entirely distributed and anyone could write software to join in. This covers item 1 and part of item 2. For sending email to friends of friends it would be good to avoid spam as much as possible. One way of doing would be requesting that friends publish a forwarding address on their own mail server in a manner similar to SRS [2]. SRS include the ability for such addresses to expire after a certain period of time (which would be convenient for this). In fact publishing SRS versions of friends email addresses would be a good option if you already use SPF [3] and SRS in your mail server. This covers item 3. The XML format could include information on how far the recipient could transfer it. For example if my server sent an XML file to a recruiting agency with my CV it could state that they could distribute it without restriction (so that they can give it to hiring managers) with the possibility of some fields being restricted (EG not tell the hiring manager what I used to get paid). For my mobile phone number I could send it to my friends with a request that they not send it on. This covers part of item 2. The URL for the friends file would of course be in the main XML file, and therefore you could have different friends lists published from different versions of your profile (EG the profile you send to recruiting agencies wouldn’t include drinking buddies etc). This completes the coverage of item 2. Then to have a friends list you have a single XML file on a web server that has the public parts of the XML files from all your friends. This means that getting a list of friends of friends would involve getting a single XML file for each friend (if you have 100 friends and each friend has 50 unique friends on average then you do 100 HTTP operations instead of 5,000). Minimising the number of web transfer operations is essential for performance and for reliability in the face of unreliable web servers (there is no chance of having 5,000 random web servers for individuals all up and accessible at the same time). This covers item 4. Item 5 is merely a nice thing to have which allows more easily replacing some of the recruiting infrastructure. As any such XML format will have several sections for arbitrary plain text (or maybe HTML) for describing various things the CV could of course be in HTML, but it would be good to have the data in XML. I posted this in the “blog” category because blogs are the only commonly used systems where end users do anything related to XML files (the RSS and ATOM feeds are XML). A blog server could easily be extended to do these social networking systems. As with a blog users could run their own social networking server (publishing their XML files) or they could use a service that is similar in concept to blogger which does it all for them (for the less technical users). Then an analogy to Planet, Technorati, etc in the blog space would be public aggregation services that compare people based on the number of friends they have etc, and attempts to map paths between people based on friends. This could also include GPG [4] data such that signing someone’s GPG key would cause your server to automatically list them in some friend category. The XML format should also have a field for a GPG signature (one option would be to use a GPG sub-key to sign the files and have the sub-key owned by the server). I don’t have any serious time to spend on implementing this at the moment. But if someone else starts coding such a project then I would certainly help test it, debug it, and contribute towards the XML design.

• [1] http://gmpg.org/xfn/and/


• [2] http://www.openspf.org/SRS


• [3] http://www.openspf.org/


• [4] http://www.gnupg.org/

Share This

So, I've been off blogging for almost three months now -- from about mid-August to now. It's been kind of guilt-ridden, and it's also been kind of a relief. Being a B-list blogebrity is a direful burden, and having some time away was restful and relaxing and energizing. But now I'm ready to come back! One of the reasons that I haven't been blogging is that once you fall behind, it's really hard to catch up. So I've decided to not do the entire task at once. Instead, I'm just going to start a page on my 2007 Hiatus and fill that up as time permits. For those of you who care greatly about exactly what I did each and every day for the last three months, you've got a spot to read it. And, truthfully, I dropped out of the B-list ranks on Technorati during my time away. I'm back to my natural position as a C-list blogger, and baby, it feels good. Get ready for some photos of my cats, coming up soon! tags: blogging blogs me c-list hiatus

Feelings of loss One of the other main reasons I haven't been blogging in the last few months is that I've been losing weight. A lot of weight. I've dropped from a high body mass index (BMI) of about 43 -- dangerously high -- to my current sane but still high 33.6. I'd like to get down to a more reasonable BMI of 30 ("overweight") by the end of the year, and be somewhere around 25 ("normal") by next summer. I can lose weight pretty easily when I put my mind to it. Well, actually, it's still insanely hard, but I'm so damn stubborn and obsessive about things, when I actually sink my teeth into them, that it seems easy to the casual observer. My recipe is simple: reduce the amount of food I eat, do low-intensity exercise about an hour a day, and measure everything as well as possible. I eat 3 good meals a day -- about 50% fruits and vegetables, 25% complex carbs like rice or bread, and 25% protein like beans, tofu, fish or cheese. I steer clear of sweets and I drink alcohol only on occasion, and seldom more than a glass or two of wine. For exercise, I've been running around Parc Lafontaine or on a treadmill three days in a row, then on the fourth day lifting weights at a local gym on rue Gilford. I still have a ways to go, but the results have been good so far, and I'm feeling like I'm getting close to the neighbourhood of what I "should" weigh. I've been getting a lot of compliments from friends and family, which is a great motivator. Most of all, I feel good running, jumping, and playing with my daughter, which is the biggest reward of all. All that said, the exercise is taking an extra 1-2 hours out of my day, and blogging has been the main thing cut out to make room. But I think I can work around that now. tags: weight loss BMI diet exercise

Road trip We're leaving Tuesday for a trip to New Jersey to visit my dad's family for American Thanksgiving. (Yeah, they're my family, too.) We're all looking forward to seeing aunts and uncles and cousins and other extended family, but we're also looking forward to spending our powerful Canadian loonies in the US. The Canadian dollar's gone up and up this last few months, and though it's no longer trading at its ridiculous high of US$1.10 (!), it's still above parity, which means our money stretches pretty well. Coupled with this is the fact that most products here in Canada are still priced as if the loonie were still worth US$0.62. It's not atypical to see a book priced for $7.99 US, $10.99 Canadian. So we're going to do some shopping for clothes, books, music and other goods while we're stateside. I plan on bringing an empty suitcase with me and bringing it back full. (The fact that I've lost a lot of weight makes shopping for clothes particularly enticing.) All within our legal limits for customs returning to Canada, of course! Not to worry, random customs official who's reading this blog for who knows what reason. I'm also looking forward to this trip because we haven't done a driving trip together in a while. Going to Thanksgiving in 2005 was Amita June's second long trip (our overnighter to Ottawa for our anniversary in Oct 2005 was her first), and I think she's going to enjoy it again this time. tags: road trip thanksgiving loonie parity shopping

Painful upgrade I just upgraded my main server, Antipater, from Debian "sarge" to Ubuntu "gutsy". I was getting pretty frustrated by being 3+ versions back from a lot of the important software running on the system. I wanted to get on Ubuntu for my server platform to have more frequent upgrades (about every 6 months). The upgrade went well, mostly. I updated /etc/apt/sources.list to use the Ubuntu archives, then got all the packages. The installation was pretty quick, even for something like 700 packages. However, when I rebooted to use the new 2.6.22 kernel (up from 2.6.8 or so), the server's responsiveness went way down. My guess is that somewhere in the 2.6.x series, one of the new schedulers is causing my particular configuration some grief. I've trimmed my cron jobs and background processes down to a minimum, but the server is still running a little too loaded. The great folks at iWeb have been really helpful, but they don't support Ubuntu, so I've got to brainstorm for myself. I'm going to have to go in over the next few days to reboot the server and experiment with other kernels -- not fun. tags: iweb ubuntu antipater

One-liners Some other odds and ends:

• It's getting cold! We had our first snow flurries a few days ago, and it's been regularly under freezing around here. Time to get winter coats out of the closet -- or, better, buy new ones in the US.
• My friends at Kokoromi are organizing an excellent games+art event called GAMMA 256 on November 28 at the SAT. Should be a lot of fun.
• One such friend, Heather Kelley is going to be talking at the Montreal Geek Girl Dinner on Tuesday. Good for her!

tags: gamma kokoromi weather heatherkelley montrealgirlgeekdinner

Inspired by a certain blog/foo post, I want to announce that I've seen my first snow of this winter last night, too. Not enough to really cover the ground, but a bit to at least give the impression the ground ist covered.

I don't mind the cold, as long as it isn't raining. Since two days it's so cold that the dog isn't muddy after walking him, and that's quite good. Still I really look forward to be in Spain next friday, and little because of the weather ;-)

And I would be really happy if I manage to do five uploads to Debian within the next seven days, though only three would already make me happy. And now back to non-Debian work...

From November 9 till November 15 I attended SAGE Days 6 in Bristol, UK. It was a conference and a coding sprint for the SAGE project, which wants to build something comparable to Mathematica, Maple, Matlab and Magma built only from open source components without reinventing the wheel. Sage also provides excellent novel implementations for many mathematical algorithms (not found in Mathematica/Maple etc.).

I was invited to give a talk about SymPy, which is a Python library for symbolic mathematics, that we are doing.

Here are my notes from each day:

Saturday: one, two
Sunday: one, two
Monday, Tuesday, Wednesday: one

Impressions

Very positive. I started SymPy two years ago, because I wanted to play with symbolic mathematics in Python, see for example my presentation I gave at this conference for details. SAGE at that time was just able to do some mathematics things, but it was very weak in calculus, which is the SymPy's main domain. This has changed last half a year, when SAGE people managed to wrap Maxima in Python (which I thought to be completely impossible), so I started to follow SAGE development more closely. After the SD6, I must say I became very excited about the project.

One problem with mailinglists, IRC and other online interaction is that it's very difficult for me to get an impression about the people and the project. Being able to meet the developers and discuss with them face to face gives me the impression very quickly and very accurately.

By far the biggest guarantee, why it is worthy for me to contribute to SAGE, is the project leader, William Stein. He is very rational and pragmatic (I like these two properties) and after many discussions with him, I came to realize that he has basically identical views on the important things as I do and were I on his place, I would do the same decisions as he did and does. That's very nice, because I can concentrate my energy on things that I like to improve and don't have to worry about other things, because I know he will do it right.

The other SAGE developers are experts and with similar attitude as William has. It's enthusiastic to be among people who make things happen. For example one of the authors of Cython, Robert, implemented during SD6 a very nice HTML output, that shows Cython code, with colors according to how many Python API calls are called on that particular line, and by clicking that line it shows the corresponding C code.

SAGE project has a high aim and it stricly goes for it, without looking too much to the right or left, and that's how it should be. And it does produce a lot of very useful and high quality stuff along the way, for example Cython (probably the best wrapper for C/C++ things now, only pypy could possibly beat it, but that's still more a research project) or the SAGE notebook, which looks like a Mathematica notebook, but better and in a browser (together with a revision history, sharing, SSL encryption, etc.).

The only little problem is that currently SAGE developers are all mathematicians and as is well-known, mathematicians looks at mathematic from a very different prospective than physicists. :) And so I need calculus, advanced calculus and only when this is working, and working well, I can build on it some more advanced features. SAGE currently goes a little the other way - it has a lot of advanced features, from number theory, modular forms, elliptic curves, etc., but the basic calculus still needs a lot of improvements. SAGE wraps Maxima, because Maxima is quite fast, very well tested, so it works well. It's difficult to extend and written in LISP and that's very bad. That's where SymPy could help - it's in Python, very easy to extend, but currently slower than Maxima (rewriting parts of SymPy using Cython, or even C directly, will make it faster, hopefully as fast as Maxima or faster).

It's not yet in Debian, but SAGE people are working on it. It's not an easy task unfortunately.

Conclusion

SAGE is a very promising young project and I think it will succeed to provide an open source alternative to Maple, Matlab, Mathematica and Magma.

So, uhm, somebody around here must have felt inspired by the French, because this very morning I noticed in the bus a note announcing a strike starting tomorrow. It will last a week. The disagreement seems to come from a difference in salaries between the workers of the company that connects Alicante with nearby towns, La Alcoyana, and the company that runs buses within the city, Masatusa. Accoring to this article (in Spanish), in La Alcoyana they earn up to a 40% less. This seems to happen because Alicante’s Town Council is responsible for transports within town, but it’s the Regional Government that regulates how La Alcoyana should operate. They say they will keep a 60% of the buses, which sounds like a lot to me (how much is it in France, Christian?). We’ll see how it goes.

It's official: I'm beginning to be a bit overloaded. Luk gently asked me about my status in the (stable) release management team. That just made a bit more guilty not doing that I'd like to do. Current TODO list involves:

• release awesome 2.0-rc1 and update website and documentation for it;
• work on rebuildd, finish and polish 0.3 version;
• run a full rebuild of the Debian archive to test rebuldd 0.3, do some QA work;
• update mod_defensible to fix problem with udns timeout;
• work on Debian release management, at least rewrite lost script for (old-)proposed-updates which were on ries'
• work on Debian Xen;
• handle a lot of waiting task on my network/servers.

Now, the thing that will help: I'm house moving this week-end with no (real) Internet connection yet. I only managed to establish a VPN over port 53/udp on a hotspot from a pub near my new apartment with 25-30 KB/s bandwidth, which is better than nothing actually.

• awesome* is asking me a lot of time right now, and since it's my last launched project, I am motivated and have a lot of idea, so I like to hack on him right now. I think I will have to postpone future release to not forget other things.

I'm going to see what happens by the end of the year and if I'm able to catch up with everything. Otherwise I might need to drop some things Life is too short.

So, our country is again in one of its recurrent strike madness. Yesterday (Wednesday), unions of the public transportation companies (mostly SNCF for trains all over the country, RATP for Paris and suburbs metros/bus system and maybe a few transport companies in other cities) called for an unlimited strike. The point is protesting against the project of harmonizing the retirement systems of these companies with the system used in private companies (AND many public ones such as Onera who I work for). The French retirement financing system is facing the challenge of all participative systems (where the current workers pay for the current retired people, contrary to cpitalization systems where one spares one's own retirement money during one's work life....I hope this is clear with my broken English). As there are less and less workers and more and more retired peoplen the load on workers is becoming harder and harder while the retirement 'salaries' (what's the word for 'pension'?) can only be lower. As a consequence, in the standard retirment system in France, ppl now have to work for 42 years to get a full pension when they retire (theoretically we can at 60....but practically, this happens at 65). In the same time, workers at SNCF, RATP and a few others still have a special retirement system with only 37 years to work and the possibility to retire when reaching 55 for some of them (good ol' days of steam trains justify the work being "hard"). All attempts to change this have failed up to now because of the power of unions at SNCF/RATP/others and the power they have to screw out the entire country. Attempts in 1999 lead to huge strike with, at that time, a strong support by the general public (who feared for their own retirement system.....the strike also being a good way to protest against the general policitcs of the government at that time...as usual). Things changed now and the majority of ppl no longer support so-called privileged people to try hanging to their special retirement system....but of course, unions still have to show their power and, anyway, very few strikers may break things a lot.....and here we are with huge strikes. Yesterday, I managed to do it well with a good train coverage on my line (1 all-stops train per 30minutes) and running at both ends (good for health!). Today was a little bit jerkier with the scheduled train being cancelled and the next one 30 minutes later...and well packed..:-) Hopefully, for tomorrow, the situation should improve as negotiations between government and unions are planned (they were already but I guess that unions had to show their strength....and check whether the average people support them like it happened in 1999....which is actually a complete failure as the general feeling over French population is "enough!"). That's good as I'm not completely sure I can sustain running 12km every day.:)

Update: problem fixed, thanks for the comments; it was MTU related issues.

Note: This is a long post, but I expect it to bring in some questions for many Linux people; I advise you to read this when you have enough time.


After the last events related to connectivity at home which have been lasting since Thursday evening and the weird fact that it seems that NAT doesn't work at home, but does at work for the same setup, I called the ISP's support and wasted 15 minutes trying to convince them at least to send a technical team with another modem just to test if that is the reason for the breakage.

Of course, talking to the ISP support and trying to convince them that there might be a problem on their side since NAT works with another provider but doesn't with them, was fruitless.

Tonight I was stuck and tried another approach, convinced I would confirm my suspicion that there is something wrong on ISP's side. Still I am not yet sure what to conclude from what happened.


So, to get a better view of what is going on, I'll describe the setup I have and what are its limitations and characteristics. People in a hurry can skip to the paragraph starting with "I tested" and stare in wonder at will.


So the connection I have is done through a DSL modem which gets the MAC of the network card connected to it and exposes that as its own to the ISP's network. This MAC seems to be quite persistent and special measures must be taken in order to be able to use another NIC to connect. The modem (or probably some machine in ISP's; the IP is 10.10.0.1) offers a DHCP address and everything should work fine.

Because of this "your MAC is my MAC" issue, when I connected the first time, I used an USB NIC since a broken router or some temporary failure would have allowed me to use the Internet connection directly from my laptop. I can say this decision has proven in time to be wise.

The router I used until now is a NSLU2 with Debian installed on it. The built in network interface always faced the internal network.

The router (which I call ritter) served as a NAT router for two machines inside the network, my laptop and my apartment mate's laptop. All until last Thursday, after which it never got back properly.



I tested (doing NAT on my laptop; the laptop shouldn't have been affected by the power problems):

• with ritter behind the laptop NAT, at home
  
• with two different virtual machines as NAT "clients", at home
  
• with ritter behind the laptop NAT, at work
• with a virtual machine as NAT client, at home
• directly from the laptop
• NAT made through a SNAT rule
• NAT made through a MASQUERADING rule
• with TTL mangled (increased by one, although is was never in the ballpark of a low TTL)

Of course, I have n-checked that /proc/sys/net/ipv4/ip_forward was set to 1, the tables had policy ACCEPT and there were no extra rules, except the basic NAT-ting stuff, the routes were correctly set on both the clients and the machine doing the NAT.


All I could see is that:

1. the machine doing the NAT was always working fine
2. at work all NAT clients worked fine
   
3. at home any of the NAT "clients" were
1. able to resolve addresses while the DNS server was in ISP territory and another LAN
2. ping the outside world (if ping was available - in D-I is not)
3. hanging when trying to get a http page
4. telnet-ting directly to the port 80 was ok (but I didn't try to "GET / HTTP/1.0")

So after all of this, I was thinking of trying to see if a new client (the laptop of my apartment mate, a Windows XP machine) would work using the connection at home. It didn't work.

Then I thought of trying to do "Internet Connection Sharing" as is called in Windows. Of course, there was some pain to find Windows XP drivers for the ASIX AX88172 network card (remember, the modem needed to see the MAC of that NIC), but I managed to find the proper one.


And, almost sure the NAT wouldn't work for this case either, I configured the new connection as a shared one. I didn't even disabled the firewall, as I was thinking I could take those down gradually.

I wasn't expecting this, not even by pure chance, but my laptop which was a NAT "client" now was able to browse, ping and do whatever was normal through NAT, while the Windows machine was doing the "Connection sharing".

I was utterly flabbergasted. And that was just the beginning.

I was expecting that the problem coincidentally went away, but after a minute I was proven otherwise. It still didn't work with Linux as the NAT-ting machine. I connected back the USB NIC to the Windows machine and I saw the same thing. NAT was just working.


At that point I was to observe an even more shocking fact: the IP that the Windows machine got was different from the one the Linux machine received, in spite of the fact that the network card was the same, so it would have made sense to get the same one. More than that, the IP that the Windows machine got was from an entirely different network, although it was a valid IP belonging to my ISP.

I was thinking that one reason why it works with Windows might be that there could be some TCP protocol twist that is differently implemented in Windows and the equipment from my ISP gets along better with the Windows network stack.


As a way to test that, I am thinking of forcing somehow the IP on the Linux machine to see if anything changes. But before doing that, I felt the urge to post these, maybe some kind soul will shed some light on this issue for me or drop a hint.

Another reason might be different DHCP servers answering, but I don't know how I can see in Windows who offered the lease.


If anyone has any clue why these weird things happen, please drop a line. I would greatly appreciate it. TIA.

For a while I’ve been trying to find some easy way to keep a few machines I admin behaving the way I want them too with minimal effort. They don’t really need much maintenance – but I would like something to help keep them all in sync. Basically, something like FAI, but much, much simpler – ideally something that takes five minutes to understand, and another five minutes to deploy; and leave the more complicated and powerful tools for when they’re actually needed. I figured what I really want was just a simple way to make a meta-package – one that doesn’t really provide any functionality, just tells apt/dpkg what I want installed (via Depends), and what I don’t want installed (via Conflicts) and adds any extra configuration stuff or local scripts that I decide I want. But doing that with a real Debian package is harder than I’m really comfortable with – I don’t want to have to worry about potential lintian errors, or rules files and debhelper commands, or writing a Makefile to get my files installed or whatever, I want something more trivial than that. Looking for meta-package creators, the only one I spotted that I thought looked likely was cdd-dev, described as “Custom Debian Distributions common files for developing meta packages”. Unfortunately it seems to just provide templates, which makes things quicker, but no less complex. Fortunately equivs (“Circumvent Debian package dependencies”) is actually used for metapackages these days, according to its maintainer on IRC and its long description:

This package provides a tool to create Debian packages that only contain dependency information. One use for this is to create a metapackage: a package whose sole purpose is to declare dependencies and conflicts on other packages so that these will be automatically installed, upgraded, or removed. Another use is to circumvent dependency checking. […]

That turned out to work much better than I remembered (from whenever I last tried it – back in ‘99 I guess?), with the only drawback being that I couldn’t add files easily. But that’s just a matter of creating a patch to equivs, which I then won’t have to worry about again. So having done that, I can now create a metapackage to do whatever I want by creating a file like:

Suite: client
Section: misc
Priority: standard
Package: ajs-client-stuff
Version: 20071114.1
Maintainer: Anthony Towns <aj@erisian.com.au>
Description: Metapackage for aj's client computers
 Depends on necessary packages, etc.
File: /etc/apt/sources.list.d/client.list
 deb http://mirror.localnet/debian etch main contrib non-free
 deb http://mirror.localnet/debian etch-proposed-updates main contrib non-free
 .
 deb http://security.debian.org/ etch/updates main contrib non-free
File: postinst
 #!/bin/sh -e
 .
 apt-key add - <<EOF
 [output of gpg --armour --export $KEY]
 EOF
 .
 ##DEBHELPER##

debhelper kindly takes care of getting the permissions right for me, and equivs will generate a full source package if I tell it to, which I can just upload to mini-dinstall and have a regular Debian repository just by writing a text file and running equivs-build. And my metapackage can add dependencies, conflicts, apt sources, cronjobs, scripts, configuration files, documentation, or whatever I happen to want – which means I can make it automatically update itself, and thus install any dependencies or remove any conflicts, which then means that modifying the config on all the machines is just a matter of updating the metapackage. And new installs is (hopefully) just a matter of doing a standard install and then adding the metapackage. Perfect. …even if it is really little more than a reinvention of rpm’s .spec files. :)

In the past I have spent about 18 months living in hotels with a couple of months of breaks in between. I have previously written about it in terms of living in London hotels [1], but I have been asked for more generic advice. Firstly the amount of possessions that you may have when living in hotels is seriously limited. For ease of travel you want to restrict yourself to one suitcase for checked luggage and one for carry-on luggage. Hotels often have short-term storage space for possessions of guests, so having a second suitcase of items that are not worth stealing (clothes and books) may be an option. But consumer electronics devices other than a single laptop computer are not an option. I read an interesting blog post on ZenHabits.net titled Minimalist Fun: The 100 Things Challenge [2] which advocates counting and limiting the number of possessions you own. When living in hotels if I considered my books as one collection and my clothes as another (having never been interested in trendy clothes they count as utilitarian items for work or leisure not objects that I seek to own) and as my mobile phone was a tool for work and my computer gear was strictly limited to items that were needed for work (and thus “tools”) my only possessions were a digital camera and some bottles of liquor! The lack of ability to accumulate possessions may be considered as an advantage or a disadvantage depending on what your aims are. If you are moving to another country for work there are three ways of doing it. The easiest is to be a permanent employee of a company that assigns you to work there - in which case they will probably pay to transport your stuff when you buy or rent a house. If you are a looking for new employment (either contract or permanent) in another country then you can either find the work before moving or after arriving there. Finding work before arriving in the country is difficult and generally only works for short-term contracts. So it’s most likely that you will either be looking for work immediately after arriving or after a short contract. In either case having better mobility increases your employment options - why restrict yourself to one city or region when you can choose from all jobs in an entire country or (in the case of the EU) half of a continent! The career benefits of being able to accept any job anywhere in the world at short notice are significant! There are situations where an employer will pay hotel bills. One example was when I was working for a London based company and they assigned us to work at the other side of London. My colleagues complained and the company paid for hotel bills for everyone Sunday night to Thursday night inclusive as well as an extra hour of pay per day as compensation for the inconvenience. For me of course one hotel was as good as another so it just meant that my employer was covering 5/7 of my living expenses. Then I had a meeting with the hotel manager and pointed out that having me check out every Friday would be bad for them as the hotel was mostly empty on the weekend and suggested that they make me a deal for the other two days - I ended up paying something like one night of hotel fees per week! If I had rented an apartment I would have still been paying the full rent (which while less than 30 days hotel fees per month would have been considerably more than 4 or 5 days of hotel fees per month). If you live in a hotel then there is always some sort of deal that can be arranged. Apart from certain busy days (such as around the Christmas and new-year time) they always want long-term guests and will be willing to reduce the price, give free dinner or drinks from the bar, etc. The cost of living in a hotel at times such as Christmas may be as much as five times the regular rate. That is a further incentive to visit friends or relatives at Christmas. If you can’t visit your family (which may be difficult if they live on the other side of the world) then finding a friend who has a spare room might be an option.

• [1] http://etbe.coker.com.au/2007/08/05/living-in-hotels/


• [2] http://zenhabits.net/2007/09/minimalist-fun-the-100-things-challenge/

Share This

SE Linux has a utility named restorecon to set (or reset) the security context. This is useful for many reasons, corrupted filesystems, users removing files or changing the context in inappropriate ways, and for re-creating files from tar files or backup programs that don’t restore SE Linux contexts. It can also be used to report the files that have different contexts to that which would be set by restorecon to verify the contexts of files. Restorecon determines the context from two sources of data, one is the policy that came with the system (including any policy modules from other sources which were loaded) and the other is the local file contexts that were created by semanage. It’s a pity that there doesn’t seem to be an equivalent program for Unix permissions. rpm has a -V option to verify the files from a package and dpkg doesn’t seem to have an option to perform a similar operation (/var/lib/dpkg/info/* doesn’t seem to have the necessary data). But even on an RPM based system this isn’t possible because there is no way to add local files into the list. I would like to be able to specify that an RPM system should have root:root as the owner and permission mode 0755 for all files matching /usr/local/bin/* and use a single command to check the RPM database as well as this extra data for the permissions of all files. Does anyone know of any work in this area? I’m going to file Debian and Fedora bug reports about this, but I would appreciate any comments first. Update: Here is an example of how this feature works in rpm:
# rpm -Vv nash
…….. /sbin/nash
…….. d /usr/share/man/man8/nash.8.gz
# chmod 700 /sbin/nash
# rpm -Vv nash
.M…… /sbin/nash
…….. d /usr/share/man/man8/nash.8.gz The “M” character indicates that the permission mode of the file does not match the RPM. There is no way to automatically correct it (AFAIK) but at least we know that something changed. With Debian AFAIK it’s only possible to verify file checksums not the permission.

Share This

Disclaimer: splashscreens should be avoided and programs should start faster. Some programs are just too slow so a splash screen is needed. Wouldn’t it be cool if all programs that showed splashscreens actually showed a splash matching the same theme as your desktop environment and your display manager? This might going to happen. Besides OOo, amarok and the gimp, which other programs uses splash screens? And where do they store their splash screens? Artists: This is also your clue to consider it. I don’t have much artist skills, but I have some ideas for the implementation. To show off something, I can start here: The plan is of course to make it as easy as apt-get install debianized-splashscreens to get debianized splash screens - and apt-get remove to get the original splash screens back. Oh - and of course easily to change for derivatives who wants some other styling.

I have had some fun during these 2 rainy days thanks to VirtualBox. I have first tried the latest Fedora 8 (upgrading from the previous release). Though the upgrade was painless, I was stucked with the Linux Guest Additions which weren’t working, due to SELinux being enforced (by default or by mistake, I am not sure). I had even opened a bug for this issue… Then I have tried OpenSuse, which also needs tweaking so that the additions run ok - the solution was on the VirtualBox forums (disabling concurrency for init scripts by changing RUN_PARALLEL=”yes” to “no” in /etc/sysconfig/boot file). Well, I haven’t extensively tested these distributions, but I particularly like the new Nodoka theme used by default in Fedora. I have even begun to work on Debian packages for both the GTK+ and the Metacity themes (I know there is already someone working on this, I will e-mail him to propose a co-maintenance if he accepts). On the other hand, I was very surprised that OpenSuse uses GNOME as default WM (maybe it isn’t new, but I haven’t seen a Suse desktop for years). Their gnome-main-menu is really nice, but really unusable for me! I guess I will try more distros in the coming weeks to compare with Debian - for now, I get the feeling I have made the good choice, except maybe for the default artwork, which is hopefully improving…

Yesterday I bought a laptop for a friend, who also asked me to install Linux on it. Since she's not computer-savvy at all, I opted for an Ubuntu. I provide here a short description of the hardware and what to expect regarding compatibility for anyone about to buy one of these. Hardware description

Model	HP 530
Part No.	GU322AA
CPU	Intel(R) Core(TM) Duo CPU T2300 @ 1.66GHz (stepping 12) - 2 MiB cache
CPU flags	fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx constant_tsc pni monitor est tm2 xtpr
Screen	330 mm x 250 mm viewable area, "glossy" wide-screen. 1280x800 pixels.
Video	Intel Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller
Audio	Intel 82801G (ICH7 Family) HDA
USB	Intel 82801G (ICH7 Family) USB2 EHCI Controller
Ethernet	Intel 82562ET/EZ/GT/GZ - PRO/100 VE (LOM) Ethernet Controller Mobile
WiFi	Intel Corporation PRO/Wireless 3945ABG Network Connection
Optical media	Optiarc DVD RW AD-7560A
Hard disk	Fujitsu MHY2120BH, 112GiB, max UDMA/100

Problems The only problems I had with the hardware were related to the sound card and the lid. The sound card had exactly the same problem as my Dell Inspiron 6400: it won't turn off the internal speakers when you plug something in the audio output jack. This is easily solved adding the following to /etc/modprobe.d/options: options snd-hda-intel enable=yes model=laptop The problem with the lid is that the screen didn't turn off when the lid closed. Just one time it did work, and stopped doing so after a reboot. Looking with acpi_listen, it seems that the acpi event isn't even generated. I don't know if this is a hardware or software problem. Also, some not very nice things should be noted about it: it has no independent media buttons for volume, suspend, etc.; only the WiFi transmitter kill and the power button, the rest needed a key chord. It has only two USB ports, which nowadays is incredibly few. No LEDs for hard dist, scroll lock or num lock. The audio jacks are on the front, which makes them very unsuitable for any straight plug. Although seldom used, it is nice to have the ability to turn the screen 180 , but this one can't do it. Finally, the battery is tiny: only four cells amounting 2 Ah of capacity. The power consumption seems a little better than my Dell: running on batteries, with low brightness, an idle GNOME desktop gave a reading of 820mA. Watching a movie from optical media in full screen ranged from 1 A to 1.3 A depending on the spinning of the media and the codec. Burning a DVD at 2x took 1.15 A The good After installing a Ubuntu 7.10, almost everything Just Worked . Of course it warned me about the non-free ipw3945 driver, but in seconds network-manager had connected to my home WLAN. Network manager could be a little more smart and turn off the WiFi transmitter when it's disabled by the user, but I guess that's not only an Ubuntu problem :). Most media keys worked out of the box, the WiFi kill switch worked OK, as did suspend to ram and to disk. Video acceleration and obligatory eye candy worked automatically. No problems either with burning a DVD, listening to music, watching a movie or connecting to my home network. The external aspect is not bad, the screen looks good, and the touch pad is very nice: just a matrix of dots over a surface that doesn't show any other sign of being an input method. In conclusion, it shows that it is a very cheap machine, but the drawbacks seem very few comparing to the good price. Tags: Planet Lugfi, Planet Debian, Tecnolog a

Best wishes to everyone in the Free Software community for the new year Vikari (VS 2064) Diwali/new year this time was kind of anticlimatic compared to last year when we were actually in India. It is cold and gloomy in NJ, and fireworks are hard to come by. (Though I did manage to scrounge up some so not a total loss in that department.) And we arrived late at the mandir for Annakut Darshan today so they were out of thor which sucks. The presents front has been the usual maddeningly practical things. The kids of course got better stuff. Shailu, for instance, got Hungry Hungry Hippos and we've been having fun playing that. So I shouldn't complain. Ma Lakshmi has blessed me tremendously over the past year and I just know this year will be even better.

I have just come back from a half week stay at the Hilton Indian Lakes resort (which is the second time in a month that I have stayed at a golf resort and club and proceeded to spend 9 hours a day in a windowless conference room). On Thursday night, an ex Chicago native wanted to show us the traditional Chicago pizza (which can be delivered, half cooked, and frozen, via Fed-Ex, anywhere in the lower 48). Google Maps to the rescue! One of the attendees had a car, and we piled in and drove to the nearest pizzeria. It was take out only. We headed to the next on the list, again to be met with disappointment; since making the pizza takes the best part of an hour, and we did not want to be standing out in a chilly parking lot while they made out pizza. So, I strongly advocated going to Tapas Valencia instead, since I have never had tapas before. Somewhat to our disappointment, they served tapas only as an appetizer, and had a limited selection; so we ended up ordering one tapas dish (I had beef kabobs with a garlic horseradish sauce and caramelized onions), and my very first paella (paella valencia), with shrimp, mussels, clams, chicken, and veggies. We ate well, and headed back to the hotel. As we parked, and started for the gate, I realized I no longer had my wallet with me so back to the restaurant we went. The waiter had not found the wallet. Nor had the busboy. The owner/hostess suggested perhaps it was in the parking lot? So we all went and combed the parking lot once, twice. At this point I am beginning to think about the consequences I can t get home, because I can t get into the airport, since I have no ID. I have no money, but Judy can t wire the money to me via western union because I have no ID. I need money to buy greyhound tickets to get home on a bus and then there is the cancelling credit cards, etc. Panic city. While I was on my fourth circuit of the parking lot, the owner went back and checked the laundry chute. I had apparently carelessly draped the napkin over my wallet when paying the tab, and walked away and the busboy just grabbed all the napkins, wallet and all, and dumped it down the chute. Judy suggests I carry an alternate form of ID and at least one credit card in a different location than my wallet for future trips. If that was not excitement enough, yesterday, I got on the plane home, uneventfully enough. We took off, and I was dozing comfortably, when there were two loud bags, and the plane juddered and lister to the port. There was a smell of burning rubber, and we stopped gaining altitude. After making a rough about turn with the left wing down, the pilot came on the intercom to say We just lost our left engine, and we are returning to O Hare. We should be in the ground in two minutes . Hearing the in , a guy up front started hyperventilating, and his wife was rubbing his back. My feelings were mostly of exasperation, I had just managed to get myself situated comfortably, and now lord only knows when we would get another aircraft. When we landed, the nervous dude reached over and kissed his wife like he had just escaped the jaws of death. And he asked if any of us knew statistics, and if we were fine now. (I was tempted to state that statistics are not really predictive, but hey). It was all very pretty, with six fire engines rushing over and spraying us with foam and all. When we got off the plane the nervous dude headed straight to some chairs in the terminal, and said his legs would not carry him further. He did make it to the replacement plane later, though. Turns out it was a bird flying into the engine that caused the flameout. Well, at least I have a story to tell, though it delayed getting home by about three hours.

I have just got a CentOS system running with a MySQL database to store account data, Postfixadmin [1] to manage the account data stored in the MySQL database, and Dovecot for serving the mail via POP and IMAP. It was a minor annoyance that Postfixadmin is not packaged for CentOS (and doesn’t appear to be packaged for Debian). I installed it under /usr/local and apart from a bug whereby it refused to talk to MySQL anywhere other than localhost it worked well enough. One thing to note is that you must not use AllowOverride None in the Apache configuration section for the Postfixadmin directory as it relies on a .htaccess file to determine who can login as the overall administrator (the person who delegates domain administration rights to the people who run the various domains). Also it was a little annoying that Postfixadmin seems to only be able to talk to a MySQL instance on localhost. The next issue was getting Postfix to talk to MySQL. For some reason (which unfortunately is not mentioned in the changelogs) the Postfix package in CentOS is built without MySQL support, but there is a macro on the second line of the postfix.spec file to enable this. Obviously at some time in the past MySQL support was added to that packaged and then removed. It’s a pity that they haven’t chosen to do what is done in Debian and create separate packages with shared objects to support MySQL, LDAP, and PostgreSQL lookups for Postfix.

• [1] http://sourceforge.net/projects/postfixadmin/

Share This

SLO2 (FTA 13e) is advertising a sports documentary called RAAM 2007 today (Saturday 10 November) at 1630 CET - that might be the Race Across AMerica and there’s no telling what language it will be in! RAI Sport Sat (FTA 13e)
has coverage of the 4 Days of Milan stage from Montichiari to Castellana on Sunday 11 November at 1700 CET. I can’t find this race on the UCI calendar - does anyone know it?