I think most people reading my blog would agree that backups are extremely important. So much important data is on computers these days: family photos, emails, financial records. So I take backups seriously.
A little while back, I purchased two identical 400GB external hard disks. One is kept at home, and the other at a safe deposit box in a bank in a different town. Every week or two, I swap drives, so that neither one ever becomes too dated. This process is relatively inexpensive (safe deposit boxes big enough to hold the drive go for $25/year), and works well.
I have been using rdiff-backup to make these backups for several years now. (Since at least 2004, when I submitted a patch to make it record all metadata on MacOS X). rdiff-backup is quite nice. It is designed for storage to a hard disk. It stores on the disk a current filesystem mirror along with some metadata files that include permissions information. History is achieved by storing compressed rdiff (rsync) deltas going backwards in time. So restoring "most recent" files is a simple copy plus application of metadata, and restoring older files means reversing history. rdiff-backup does both automatically.
This is a nice system and has served me well for quite some time. But it has its drawbacks. One is that you always have to have the current image, uncompressed, which uses up lots of space. Another is that you can't encrypt these backups with something like gpg for storage on a potentially untrusted hosting service (say, rsync.net). Also, when your backup disk fills up, it takes forever to figure out what to delete, since rdiff-backup --list-increment-sizes must stat tens of thousands of files. So I went looking for alternatives.
The author of rdiff-backup actually wrote one, called duplicity. Duplicity works by, essentially, storing a tarball full backup with its rdiff signature, then storing tarballs of rdiff deltas going forward in time. The reason rdiff-backup must have the full mirror is that it must generate rdiff deltas "backwards", which requires the full prior file available. Duplicity works around this.
However, the problem with duplicity is that if the full backup gets lost or corrupted, nothing newer than it can be restored. You must make new full backups periodically so that you can remove the old history. The other big problem with duplicity is that it doesn't grok hard links at all. That makes it unsuitable for backing up /sbin, /bin, /usr, and my /home, in which I frequently use hard links for preparing CD images, linking DVCS branches, etc.
So I went off searching out other projects and thinking about the problem myself.
One potential solution is to simply store tarballs and rdiff deltas going forward. That would require performing an entire full backup every day, which probably isn't a problem for me now, but I worry about the load that will place on my hard disks and the additional power it would consume to process all that data.
So what other projects are out there? Two caught my attention. The first is Box Backup. It is similar in concept to rdiff-backup. It has its own archive format, and otherwise operates on a similar principle to rdiff-backup. It stores the most recent data in its archive format, compressed, along with the signatures for it. Then it generates reverse deltas similar to rdiff-backup. It supports encryption out of the box, too. It sounded like a perfect solution. Then I realized it doesn't store hard links, device entries, etc., and has a design flaw that causes it to miss some changes to config files in /etc on Gentoo. That's a real bummer, because it sounded so nice otherwise. But I just can't trust my system to a program where I have to be careful not to use certain OS features because they won't be backed up right.
The other interesting one is dar, the Disk ARchive tool, described by its author as the great grandson of tar -- and a pretty legitimate claim at that. Traditionally, if you are going to back up a Unix box, you have to choose between two not-quite-perfect options. You could use something like tar, which backs up all your permissions, special files, hard links, etc, but doesn't support random access. So to extract just one file, tar will read through the 5GB before it in the archive. Or you could use zip, which doesn't handle all the special stuff, but does support random access. Over the years, many backup systems have improved upon this in various ways. Bacula, for instance, is incredibly fast for tapes as it creates new tape "files" every so often and stores the precise tape location of each file in its database.
But none seem quite as nice as dar for disk backups. In addition to supporting all the special stuff out there, dar sports built-in compression and encryption. Unlike tar, compression is applied per-file, and encryption is applied per 10K block, which is really slick. This allows you to extract one file without having to decrypt and decompress the entire archive. dar also maintains a catalog which permits random access, has built-in support for splitting archives across removable media like CD-Rs, has a nice incremental backup feature, and sports a host of tools for tweaking archives -- removing files from them, changing compression schemes, etc.
But dar does not use binary deltas. I thought this would be quite space-inefficient, so I decided I would put it to the test, against a real-world scenario that would probably be pretty much a worst case scenario for it and a best case for rdiff-backup.
I track Debian sid and haven't updated my home box in quite some time. I have over 1GB of .debs downloaded which represent updates. Many of these updates are going to touch tons of files in /usr, though often making small changes, or even none at all. Sounds like rdiff-backup heaven, right?
I ran rdiff-backup to a clean area before applying any updates, and used dar to create a full backup file of the same data. Then I ran apt-get upgrade, and made incrementals with both rdiff-backup and dar. Finally I ran apt-get dist-upgrade, and did the same thing. So I have three backups with each system.
Let's look at how rdiff-backup did first.
According to rdiff-backup --list-increment-sizes, my /usr backup looks like this:

        Time                       Size        Cumulative size
-----------------------------------------------------------------------------
Sun Apr 13 18:37:56 2008         5.15 GB           5.15 GB   (current mirror)
Sun Apr 13 08:51:30 2008          405 MB           5.54 GB
Sun Apr 13 03:08:07 2008          471 MB           6.00 GB

So what we see here is that we're using 5.15GB for the mirror of the current state of /usr. The delta between the old state of /usr and the state after apt-get upgrade was 471MB, and the delta representing dist-upgrade was 405MB, for total disk consumption of 6GB.
But if I run du -s over the /usr storage area in rdiff, it says that 7.0GB was used. du -s --apparent-size shows 6.1GB. The difference is that all the tens of thousands of files each waste some space at the end of their blocks, and that adds up to an entire gigabyte. rdiff-backup effectively consumed 7.0GB of space.
Now, for dar:

-rw-r--r-- 1 root root 2.3G Apr 12 22:47 usr-l00.1.dar
-rw-r--r-- 1 root root 826M Apr 13 11:34 usr-l01.1.dar
-rw-r--r-- 1 root root 411M Apr 13 19:05 usr-l02.1.dar

This was using bzip2 compression, and backed up the exact same files and data that rdiff-backup did. The initial mirror was 2.3GB, much smaller than the 5.1GB that rdiff-backup consumes. The apt-get upgrade differential was 826MB compared to the 471MB in rdiff-backup -- not really a surprise. But the dist-upgrade differential -- still a pathologically bad case for dar, but less so -- was only 6MB larger than the 405MB rdiff-backup case. And the total actual disk consumption of dar was only 3.5GB -- half the 7.0GB rdiff-backup claimed!
I still expect that, over an extended time, rdiff-backup could chip away at dar's lead... or maybe not, if lots of small files change.
But this was a completely unexpected result. I am definitely going to give dar a closer look.
Also, before I started all this, I converted my external hard disk from ext3 to XFS because of ext3's terrible performance with rdiff-backup.

Habits control our choice sometimes more than we would like to admit… New mobile phone Since about two weeks ago I’ve a new mobile phone. The Nokia E51 will replace my slowly dying Nokia 6130i. I knew I needed a new mobile phone when my 6310i started to turn off itself shortly after I turned it on. I needed up to about ten times switching it on to make it stay on. Sometimes it already switched itself off before I could enter the PIN. Looks like a loose contact, but I never figured out where it is. Although I know about Nokia’s behaviour in Germany, I still had to buy a Nokia, because after using a 6130 (the GSM 1800 only clone of 6110 and 6150), a 6210i and the already mentioned 6130i over the last decade, I got so used to how Nokia mobile phones are navigated and how you type with Nokia phones (blank on 0, point and comma on 1, case changing on #), everything else (especially those with blank on 0 and case changing on *) would be worse than the half-dead mobile phone, I’m currently using. Spoilt for choice So which Nokia? For a long time I refused to buy a mobile phone with a camera or radio in it. But since the E70 was no more available (and is said to have quite buggy software) and the E61 has been replaced with the E61i, there are no more smartphones without a camera, at least not from Nokia. But I also found some useful uses of camera phones. After a while I could track down the number of choices to four: Communicator E90, E61i, E65 or E51: The picture above shows that the main differences of those models is size: Although having a QWERTY keyboard on the phone would be nice (for ssh, Jabber, the web, etc.) and the E90 being only slightly bigger than the 6310i on the paper, the size difference to the 6130i is more than only noticeable since the 6310i tapers off at the top. Besides, for the price of an E90, I get an E51 and an EeePC together… (Thanks to maol in whose blog I read about Sizeasy.) The E61i also has a (very small) QWERTY keyboard and is primarily only much wider than any of the other phones. It even has no bigger screen resolution than the E51 or E65. (Only the no more available E60 – a normal monoblock smart phone like the E51 – had a better resolution: 352x416 pixel instead of 240x320 pixels.) And since I usually carry my mobile phone in my trouser pockets, width matters most. So I had the choice to either get a phone which is too big for my trouser pockets or one without a QWERTY keyboard. The I remembered those foldable external keyboards for PDAs. There are at least three different makers of foldable bluetooth keyboards said to be working with Nokia Symbian S60 3rd Edition phones, so a QWERTY keyboard on the phone itself was no more important. (Only passwords will need to be entered over the number keypad since I don’t want to broadcast them… ;-) The choice between E65 and E51 was made easier by their reviews (E65, E51) at Xonio: The E65 seems to have not that good standby and phoning times while the E51 seems to be quite good regarding endurance. I looked through the usual shops around Z¨rich HB: Swisscom Shop, MobileZone, Phonehouse: All had the same prices (about CHF 250 for a two years contract at CHF 25 per month), except that Phonehouse had no E51 available in the shop. Interestingly digitec had a much lower price (CHF 100 for the same contract) and the choice of color (the shops always only offered one color), so I ordered a black one there. Converting a prepaid card to a postpaid contract isn’t that easy I wanted to change from a prepaid card to a postpaid contract, both at Swisscom, so I already own a SIM card. But digitec only offers new contracts including a SIM card or contract renewals, but no switching to a contract with keeping the number. And a new SIM card costs CHF 40 extra in their online shop. So I called their hotline and asked. The answer was: I need a new SIM card since prepaid SIM cards can’t be converted to postpaid SIM cards (but can be used with different providers). When I came to the shop, the employee needed three tries to fill out the Swisscom form for the number migration and still did it wrong somehow. No postpaid contract acknowledgement from Swisscom after two workdays. So I called their hotline. They told me, the wrong SIM card number has been entered and I need to make digitec to enter the correct one. A few days later back at the shop they were overextended. After a while an internal e-mail was on the employee’s screen which clearly stated that in case of prepaid to postpaid conversions (and a few other cases) no new SIM card must be given out and if this happens too often for the same employee he will be charged the CHF 30 a new SIM card costs digitec… (So they have a 25% margin of every sold SIM card…) About one hour after they closed their doors (I was there about ten minutes before shop closing time) Swisscom had accepted the contract changes and I had a credit note of CHF 40 for the erroneously sold SIM card. And the mobile phone became even cheaper than in all the other shops. :-) New gadget, new features So after a week, I can say that in general I’m quite happy with the new phone. It has a nice web browser, an IMAP over SSL capable mail reader and a feed reader, it can connect to the internet via WLAN and the 240x320 resolution isn’t as bad as I expected. I already have a Symbian port of PuTTY on it and sshing into my workstation works fine, even if I currently only have the phone keyboard and T9 as input device and helper. I also have Opera and Opera Mini installed, but to my own surprise the included web browser from Nokia (said to be based on Apple’s HTML rendering engine WebKit which itself is based on KDE’s HTML rendering engine KHTML) is way better, especially in navigation, even although Opera Mini 4.1 caught up a little bit in comparison to Opera Mini 4.0. (Hey, and you hear that from a web browser fetishist and Opera fan!) The only thing which currently really bugs me on the builtin web browser is that even an enforced updating of my feeds sometimes just results in nothing. Maybe a firmware upgrade can help… As barcode reader, I have installed the i-nigma Reader. (The Quickmark QR Code Reader download just showed the content of something which seems to be a Windows DLL instead of downloading it. *plonk*) It’s amazing how fast the i-nigma Reader recognizes a 2D barcode from Semapedia on my laptop screen. Of course I also have ScummVM on my new Symbian phone. I will also play around with Amora which turns your Symbian S60 mobile phone into a remote control for your presentations on Linux (or any other unixoid operating system) running laptop as soon as I managed to get an amd64 Debian package of it. (Currently there seems only i386 packages and no source packages available, but this may be due to the “Show all downloads” link gives a server error…) Oh, and many thanks to foosel since I found Amora in her blog. BTW: Any recommendations for a free (preferably free as in DFSG) Jabber and/or IRC client for Symbian S60 3rd Edition? I already downloaded and installed Gizmo5, but somehow it refuses to work each time I try to create an Gizmo account. Accessories Since the E51 has no QWERTY keyboard, I ordered a Nokia SU-8W Foldable Bluetooth Keyboard at Brack. It was a little bit bigger and thicker than expected, but OTOH the metal case seems to be very stable and robust. Since this keyboard is designed to fit on Nokia mobile phones it also has the two Nokia typical soft keys and the middle select key. So nearly all phone functions can be used with the external keyboard, even turning off the phone’s key lock. Only locking the phone’s keys again doesn’t work via the external keyboard. Additionally I equipped my E51 with a 2GB microSD card. Probably a bluetooth headset for driving will come once, too. What the Nokia 6310i did better than the E51 There are a few things which are annoying regarding Nokia’s UI consistency over the years. That the backspace key is no more the right soft-key is ok. It took me only five tries to get my e-mail account setup without hitting the abort key (no “Do you really want to abort?” questions ;-) instead of backspace key. But what’s really annoying is that the menu navigation via number keys only works for the first level and no more for all levels. So no more “menu 4 4 4” to switch to manual network selection. It’s also annoying that you (or at least I ;-) can’t enter phone numbers as the recipient of SMS directly anymore, at least those SMS never reach their receipient neither do I get an error message. Same counts for the missing acoustic acknowledgment of locking the keypad. You only hear pressing the first key but not even the second key anymore. And if you press the volume keys on the side of the phone, you also have neither acoustic nor visual feedback if you pressed them hard enough so that the volume changed. The 6310i had visual and acoustic feedback. The alarm clock in the E51 seems to be artifically castrated: After having pressed the snooze button two or three times there is no more snooze button on the right the soft key anymore. With the 6310i you could press snooze as often as you want. Only disadvantage with the 6310i in regards of the alarm clock: the snooze time was much too long (10 minutes)… Oh, and what’s also annoying is that I can’t move over the whole addressbook of my 6310i in one piece but have to send each contact via bluetooth or infrared and then the E51 even get’s the contact names mixed up: ‘Beckert, Axel’ becomes ‘Firstname: “Beckert,” Lastname: “Axel”’… Great! I have to edit nearly all contacts manually… The cut and paste feature helps here, but it takes about one to two dozens of key clicks to copy the whole content of a filed into the clipboard… The E51 can run several applications at the same time and that you can switch between them any time. While that’s generally a nice feature I started using quite soon, it’s sometimes annoying that you have to wait up to a second or so after you’ve chosen some menu entry until you can do anything further. Also the screen often flickers while loading applications, showing them, then showing only the background, showing them again, etc. … but finally I already got used to the new mobile phone so much that I already have the feeling that my old 6310i became more thick since I have the E51. (Won’t think about how thick the about ten years old 6130 feels now compared to the slim E51… :-)

This is the third plugin I have been working on for Rails - It's the one that still needs most work to be fully usable (for what I originally envisioned it), but is almost there - I have not touched it (nor the other two I recently presented here, acts_as_catalog and Real FK because real-life has demanded my time on various other fronts.
Anyway, this is IMHO the most interesting of the three plugins I've written so far.
So, following what I did with the other plugins: You can go to acts_as_magic_model's main page, or jump straight to its SVN repo. And the basic description follows:
Rails plugin to allow for extensible models, where inter-model relations are inferred from the database's structure, and not necessarily from explicit declarations in the models.
This means, when one of your models acts_as_magic_model, this plugin will try to infer all the basic relations (has_many, belongs_to and has_and_belongs_to_many) its base table has with other tables in the database, adapting the model correspondingly. Using the plugin In order to use this plugin, you only have to declare it in your model. As an example, say you have the proverbial project-management system, where you have projects (each of which can be of several different types) and people, and a HABTM relation between people and projects. So, you have the following tables (expressed as migrations here):

    create_table :people, :force => true do  t 
      t.column :name, :string
    end
    create_table :project_types, :force => true do  t 
      t.column :name, :string
    end
    create_table :projects, :force => true do  t 
      t.column :name, :string
      t.column :project_type_id, :integer
    end
    create_table :people_projects, :force => true, :id => false do  t 
      t.column :person_id, :integer
      t.column :project_id, :integer
    end

Using acts_as_magic_model, you can skip declaring the relations in your models, like this: (of course, each of the classes still has to be declared in its own file)

    class Person < ActiveRecord::Base
      acts_as_magic_model
    end
    class Project < ActiveRecord::Base
      acts_as_magic_model
    end
    class ProjectType < ActiveRecord::Base
      acts_as_magic_model
    end

And the gaps will be filled in for you - that is, you can go on and ask for Project.find(:first).people, ProjectType.find(:first).projects.size, Person.find(:first).projects.map pr pr.project_type , and whatever you fancy.
In future versions of the plugin, I expect even to get rid to explicitly declare the class declarations.
Of course, you should be warned: Initializing a model using this plugin is quite database-intensive. It will clutter your logs, and it might be unbearable if you use it in development mode. Still, its convenience is very often worth it.
Its main uses should be when prototyping and when designing a system that needs to be flexible to the data models themselves - If you don't expect your system's data structures to be highly malleable, you should probably use acts_as_magic_model only as a prototyping aid.

1/2 of apt-listbugs job on merkel removed. There are two batch jobs running on merkel, (1) doing cp -al of BTS metadata to work around the fact that BTS metadata is not made publicly available, and (2) creating of index of bugs of certain severity. Today, I received a 400MB email complaining that every single file cannot be hardlinked. Apparently /org/scratch is no longer on the same partition as /org. I checked and it looks like I no longer need to keep the BTS metadata public. Since etch release of apt-listbugs, BTS SOAP interface is used instead to query that information.

It's a bit strange. Still. Writing this personal part of my blog, opening some of my most inner thoughts to the wild public. Though, so wild it doesn't seem to be. To be honest I can't remember having received any bad feedback on my personal stuff, only positive, supportive ones. (Or, there was one. Though, it wasn't related to the core of the personal section but someone thinking it would be "cool" to misinterpret some statement therein and try to hurt me with it. It only made me laugh at them, trying to "use" it as an argument.)
No bad feedback might be related to that I don't have comments enabled because I don't want to have a moderation system that would make it look like I filter out bad comments but I also don't want to open it up to SPAM. And people who propably usual leave scathing comments don't consider it convenient to address me directly, via any IM system, including emails. Anyway, opening in that way has quite some benefits: For a start, it helps me myself to keep track of things that happened. Secondly, it hopefully helps others that are in similar situations to see that they aren't alone out there and that one can survive with not hiding it. But last but not least some people address me and provide me with interesting links on the topic. I think they shouldn't be just hidden in my personal mailbox so I am going to offer them to a broader audience here. I won't show the names of who sent them along, I'm not sure if they would like being connected to the topic. But they can be assured of my blessing for offering them to me. First link I like to hand out is an article from advocate.com about a pregnant husband. Yes, this was no typo and the reason why I haven't posted it right the next day because I received that link on March 31st. I can just wish all the best to Thomas, Nancy and their yet unborn girl. Looking forward to see baby photos. :) The second article I got sent lately is When Girls Will Be Boys. It is about the transition story of Ray and acceptance problems. Pretty long but definitely worth reading. Again, thanks to the people who offered me the links to the articles, I truly appreciate them—and I hope some of the people reading my blog will too, or at least that it might change their perception and opinion on "such people".

I uploaded xulrunner 1.9~b5-1 yesterday, and today was webkit’s turn, with an upload of svn revision 31841, which happens to be the last revision on trunk as of writing. Thanks to Mark Rowe, the most problematic crashers I experienced with webkit while preparing this upload have been fixed in revisions 31821 and 31787. This had the side effect to delay the upload enough that we now have the benefit of improved SVG animations support, and CSS gradients. For those who like numbers, you can take a look at the Sunspider results for xulrunner 1.9~b5 (running mybrowser ; very similar results to what I got with 1.9~b4), and Sunspider results for webkit r31842 (when you compare to previous results for webkit r27674, there are significant improvements). For another kind of numbers:

~/git/xulrunner$ git diff upstream/1.9... filterdiff -x b/debian/* -x a/configure diffstat tail -1
36 files changed, 507 insertions(+), 291 deletions(-) Compared to:
~/git/xulrunner$ git diff upstream/1.9...1.9+b4-1 filterdiff -x b/debian/"*" -x a/configure diffstat tail -1
53 files changed, 932 insertions(+), 466 deletions(-)

~/git/webkit$ git diff upstream... filterdiff -x b/debian/* diffstat tail -1
1 file changed, 4 deletions(-) Compared to:
~/git/webkit$ git diff upstream...0+svn27674-4 filterdiff -x b/debian/* diffstat tail -1
17 files changed, 61 insertions(+), 18 deletions(-)

Somehow, I prefer to work on webkit…

Jeez, I wasn't involved in the nomination process this year, so I completely missed the fact that Wikitravel is a nominee for the Webby Awards this year. I'm now a part of IADAS so there's a conflict-of-interest for me, but I'd recommend checking out the People's Voice Webby Voting. tags: wiki wikitravel webbyawards

Sign your mail I find it a little mind-boggling how many people complain about problems of email identity, like spam, e-mail spoofing and phishing, yet don't do anything on their own side to encourage strong identity on email. Everybody should use digital signatures on their email as a matter of course. It is absurdly easy to set up a GnuPG key for your email address. It takes only a few minutes. And you can sign up for an S/MIME key, too -- about $20/year, and supported even more widely by email clients. And organizations should send out email with signatures, too. Welcome email, password updates, and the like should all be signed. Phishing gets a lot harder when consumers are used to digitally-signed mail. If we're really serious about email abuse, we need to take the extra step at the client level. tags: email pgp gnupg smime phishing spam

My cousin Greg Coker has created an eBay auction for Football cards with the proceeds going to a charity that protects animal welfare (I can’t remember the name - I’ll update this post later). He also has a bunch of other eBay auctions of football cards going which are not for charity. The charity auction is held in association with SEN (Sports Entertainment Network - a sports talk-back AM radio station) [1]. This afternoon Greg was interviewed on SEN about football cards in general. He gave a good talk, he could probably do some professional radio work if he was interested. Greg’s cards are from the VFL (Victorian Football League) before it became the AFL (Australian Football League) [2]. The cards used to be sold in “milk bars” (small stores that sold a variety of junk food and some essential food items including milk - most such stores are closed now as they have been replaced by petrol stations and supermarkets) and each pack of ~5 cards had some crewing gum included (which Greg often discarded because he didn’t like it - he should have given it to me, I was not so fussy). The back side of the cards had a jigsaw picture which I have never seen anyone complete (I expect that Greg has assembled at least one jigsaw as he has some sets). Probably the way the cards were collected, traded, etc is very similar to sports based cards from other countries (such as baseball cards in the US). On the animal front, I’ve had a mother cat and four kittens move into the shed in my back-yard. The mother cat has no collar and is not known by anyone in the area so she appears to have been dumped by her owner when she got pregnant. There are four kittens, one is ginger, one is black, and two are mottled part black and part ginger. They are all healthy and friendly and the kittens are all really cute. The kittens have become used to being patted and handled by humans so it will be easy to make them household pets. If an owner is not found for them then they will probably all end up being put to sleep (unfortunately I can’t keep them so I’ll have to deliver them to the local council). If anyone in Melbourne, Australia wants some free cats then I would be happy to deliver them. I’ll supply as many cats as desired. I can’t give away the mother until the kittens have been given away, so if you want the mother cat (dark coloured) then you may have to wait for a while. Judging by the date that I first noticed them (when they were walking around, had their eyes open, and ate solid food) the kittens would have to be at least 7 weeks old. It’s recommended that kittens not be given away before they are 8 weeks old and given that it will probably take a week to organise anything I expect that anyone who reads I don’t think that there is any risk of giving them away too early. Please let me know by email or a comment if you are in the vicinity of Melbourne, Australia and want a new pet (or several new pets).

• [1] http://www.sen.com.au/


• [2] http://www.afl.com.au/

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Quite some time back, I wrote about my disappointment that Ampad had ceased manufacturing their Quad Ruled Steno Books, which I use to make notes to myself on just about everything. Several of my friends in Europe responded that similar pads in A5 size were commonly available in retail stores, and I quite happily bought a few on a trip to Germany. Then, one of my colleagues at work had some nice notebooks made up for a customer event with grid paper and suitable logos on the cover that I grabbed a few of and have used quite happily. Sometime in the intervening years, Ampad started producing these pads again, but with a different product number, 42036. I stumbled over some at a local office supply store and bought a big pile... others have noticed too, and sent me email about it, which is why I'm taking the time to write this... Yes, I'm much happier now!

Wikipedia, though increasingly becoming an everyday fixture for many in the Wired World, means a lot of different things to different people. If you want to take a fascinating look into what one person, Joe Reagle has written about this unwieldy project, community and encyclopedia, take a look here. He recently defended his dissertation and I have read it through and through a couple of times. It has some great insights about the significance and culture of Wikipedia by laying bare its cultural dynamics as well as putting it in historical context with similar encyclopedic endeavors.

Having recently been through the process, I've managed to come out the other-side with some some advice for anyone taking this on.

• To start out, the link for making appointments at the Australian Consulate is VisaPoint. I found it was remarkably well hidden.
• Upon entering the country, it's quite likely the immigration officer won't be that familiar with the E3 Visa. I'd recommend you watch them and very politely correct anything you think wrong, in my case my Visa was incorrectly entered as E3-Dependent along with my wife (proving that the system doesn't actually keep referential integrity between an E3 and an E3D holders).
• You can not get paid before receiving a social security number. You can not apply for a social security number within about 10 days of entering the country, as there is a lag between immigration and social security systems. Once you apply it will take a few weeks for the card, but you can probably go back to the office with sufficient ID within two days and receive a print-out of the number. You can call the office you filed with first and they can tell you if it's worth coming in to try it. In the absolute worst case, if things screw-up, you could be in for a long wait. Your company may be able to loan you money if things get desperate.

If anything really stuffs up you'll have to enter the US immigration services, which is no fun. If this happens to you in the Bay Area go straight to the San Francisco office; the San Jose office doesn't have deferred inspections so you'll probably just have to go there anyway.

Your dependent on the E3D Visa will need to fill out an I-765 work authorisation form. This will take up to 3 months to process; you can find out the approximate queue time here. The form doesn't appear to have been updated for E3D; I would strongly recommend getting a lawyer to file it for you so you don't stuff it up. Budget about $400. After this has been processed, the dependent will then need to file for a SSN before they can be paid.

Tax is a black-art. In California expect to pay something like 20-25% federal, 10% state and up to 7% more for Medicare and social security. Expect another $80/month for health insurance.

You can get a bank account without a SSN easily. A good way to transfer money is OzForex, but watch out for fees on the US side (you may have to do wire-transfers which cost about $10 a go, though some banks have bill-pay). The country still runs on cheques for some reason.

You can rent without a SSN, but it will cost you. Budget for 2 months extra rent as deposits and paying ahead.

A car lease is probably a good way to go. Finance will usually look at your visa and only give you a two-year loan, and with no credit that will be at a very high interest rate. In California you can get a 2 year lease on a base model new car (sticker price ~$17,000) drive-away for a down-payment of about $2500 and then $250/month plus taxes. Insurance will be about $120/month on-top of that. The beauty is you just give it back when you go home. For long holiday trips SUV rental may contribute to global warming, but is a very comfortable way to see the country.

In California you'll need to book in for a driving test to get a license; you can't do this in a rental car but some local driving schools offer a short introduction course and then let you use their car for the test.

If you're living in temporary accommodation without great facilities Dream Dinners is a good way to easily get some meals together.

In the Bay Area, Yelp is an awesome resource.

Comcast make Telstra look like a well-run, efficient and customer focused organisation!

Feel free to drop me a line if you're thinking of taking an opportunity and have any questions.

After my moderately successful attempts at learning git, I have now tackled Mercurial and found it easy to understand and use. I can't quite see where git is better, so I guess I'll stick with hg now. Output so far is a script I call hgdebuild, which I'll probably package when it's a bit less rough around the edges (yes, I know about hg-buildpackage, but I didn't really like it, and it appears to be orphaned at the moment anyway). Also, with Mercurial, I very easily could address the main problem I've always had with distributed revision control systems: With Subversion, it's easy to work on different computers, and backing up my home directory has become less critical (an important aspect on my Laptop). Both of these are not true when suddenly .hg in my working dir is the backing store.

$ cat ~/.hgrc
[hooks]
commit.push = [ -f .hg/dopush ] \
    && ping -w 1 -c 2 -q -i .2 mygitserver.example.com >/dev/null 2>/dev/null \
    && hg push \
      true

(Probably this problem has been solved before. Comments welcome.) Comments: From the person with madduck in his email address: Bzr checkouts, or a similar Git hook.

Children should be trained at an early age that the only real OS comes from Redmond. Stupid gadgets reinventing the wheel and then using Windows-only drivers for their non-standard interfaces.

IP, as a field of law, sometimes strikes as one unbelievably large and profitable game of make believe and this case, concerning a digital adaptation of chess-like game, a dead (famous) Marxist, his estate, and widow, makes this “game” all the more absurd (but somewhat entertaining, as all games should be)

I have mostly shifted my main development language to Ruby, as most of the work I do tends to be pretty well covered with Rails. That's not new, however - What is new is that I feel I have got to the point where I actually have something to share. And it feels very good.
So my next couple of posts (three, actually) will be covering some plugins I've written. They are, of course, just sketched - but they work reliably enough to be deemed as useful by their author ;-)
Today I will start by blogging about RealFK. Of course, I will be copying from its documentation/description - I wrote it as well, so I'm not really plagiarizing my own site. I'm not suing self. You can of course also browse the RealFK SVN tree. References Rails is built upon a "dumb database" concept. Rails assumes the database will not force restrictions upon the user - i.e. that the model validators are all there is. But I disagree ;-) I was raised with PostgreSQL, not with MySQL, and I do believe the database can and should impose sane values - It should impose trust on the data..
So, if you want to create a relation field, properly acting as a foreign key and refering to another table, instead of doing it via the ActiveRecord::ConnectionAdapters::TableDefinition#column (or even ActiveRecord::ConnectionAdapters::TableDefinition#references) methods, declare them with add_refrence:

  def self.up
    create_table :proposals do  t 
      (...)
    end
    create_table :proposal_types do  t 
      (...)
    end
    create_table :proposal_statuses do  t 
      (...)
    end
    add_reference :proposals, :proposal_types
    add_reference :proposals, :proposal_statuses, :null => false, :default => 1
  end

The corresponding fields (proposal_type_id and proposal_status_id, respectively) will be created in proposals, and the RDBMS will impose a Foreign Key constraint. The references can be removed via remove_reference, i.e., for inclusion in down migrations:

  def self.down
    remove_reference :proposals, :proposal_types
    remove_reference :proposals, :proposal_statuses
    drop_table :proposal_statuses
    drop_table :proposal_types
    drop_table :proposals
  end

Of course, in this case the remove_reference call is not really needed - But if you are dropping a table that is referred to from a table that will remain existing, you will have to remove the foreign key constraints (that is, the referring columns). Join (HABTM) tables When you define a simple has_and_belongs_to_many (HABTM) relation in your model, you are expected to create an extra table representing this relation. This is a very simple table (i.e. it has only a row for each of the related table‘s IDs), and it carries foreign key constraints.
Please note that join tables are not supposed to carry any extra columns - If you need to add information to join tables, think twice and better use a has_many :elements, :through => :othermodel declaration, and create the othermodel table manually. To create a HABTM table representing that each person can attend many conferences and each conference can be attended by many people:

  def self.up
    create_table :people do  t 
      (...)
    end
    create_table :conferences do  t 
      (...)
    end
    create_habtm :people, :conferences
  end
  def self.down
    drop_habtm :people, :conferences
    drop_table :people
    drop_table :conferences
  end

The last call will create a conferences_people table (according to Rails' conventions, table names are sorted alphabetically to get the join table‘s name).
Note that in this case, in the down migration, the drop_habtm call must appear before the drop_table calls, as it carries foreign key constraints.

Martin, sorry for calling you Madduck on the debian.ch-mailinglist. Luckily I didn’t use that name during our meeting in Zurich last week. *pfuh* To take part in the pdo-game with my own name (being Michael Prokop ;-)): as many of you might know I’m known as Mika in the community. The name was invented for me around 1999 (IIRC) by a greek flat collegue who liked to call me “Mika” - refering to Mika H kkinen (for whatever reason). From that on several people started to call me that way. I’m signing mails “to the community” with that nick since many years as well as using it in usenet and on freenode (IRC); on OFTC (another IRC network) I’ve to use mikap instead because mika was registered by another user already. Outside “the community” I’m usually known as Michael, good friends also use Michi and the family of my girlfriend uses Michl when the sister of my girlfriend (named Michaela and known as Michi as well) is present. Oh, and during grammar school I was AKA Proke.</secret> So calling me Mika is perfectly fine because it’s a kind of uniqueness for me. There might be just too many Michaels around and at least in Austria my nickname is everything but common. Quoting the marketing department: Great trademark! Oh and my speech parser knows to handle Michael, Michi and Michl as well - though it strongly depends on the situation, place, environment,…. Oh but using Proke is like talking to /dev/null - you’ve never heard of that name, ok?

The new release from the Debian EEE PC Team is simply great - it works flawlessly to install a fully functional Debian install onto an EEE PC over wireless. You only need a 16 Mb USB stick (or SD card) to boot from. The only remaining bug that people are still working on is the selection of the wireless network - int the current build the installer autoselects the strongest signal by default and if you want another you need to go back and reconfigure the network in the installer. Great work guys! BTW: This got me thinking - it shouldn’t be too hard to take over the EEEPC from the default installation without having to have a USB stick or an SD card The default EEE PC setup consists of a (read-only) system partition and a user partition overlay. It should be simple to download the 16 Mb D-I boot image, save it to the system partition and write a boot loader that would allow the choice between normal boot, EEE PC rescue boot and Debian installation boot. With a bit of pre-seeding we could have the d-i install a Debian instance in place of the user partition unless the user overrides that.