The Debian Edu and Skolelinux distribution have users and contributors all around the globe. And a while back, an enterprising young man showed up on our IRC channel #debian-edu and started asking questions about how Debian Edu worked. We answered as good as we could, and even convinced him to help us with translations. And today I managed to get an interview with him, to learn more about him. Who are you, and how do you spend your days? I'm a 25 year old free software enthusiast, living in Romania, which is also my country of origin. Back in 2009, at a New Year's Eve party, I had a very nice beer discussion with a friend, when we realized we have no organised Debian community in our country. A few days later, we put together the infrastructure for such community and even gathered a nice Debian-ish crowd. Since then, I began my quest as a free software hacker and activist and I am constantly trying to cover as much ground as possible on that field. A few years ago I founded a small web development company, which provided me the flexible schedule I needed so much for my activities. For the last 13 months, I have been the Technical Director of Funda ia Ceata, which is a free software activist organisation endorsed by the FSF and the FSFE, and the only one we have in our country. How did you get in contact with the Skolelinux / Debian Edu project? The idea of participating in the Debian Edu project was a surprise even to me, since I never used it before I began getting involved in it. This year I had a great opportunity to deliver a talk on educational software, and I knew immediately where to look. It was a love at first sight, since I was previously involved with some of the technologies the project incorporates, and I rapidly found a lot of ways to contribute. My first contributions consisted in translating the installer and configuration dialogs, then I found some bugs to squash (I still haven't fixed them yet though), and I even got my eyes on some other areas where I can prove myself helpful. Since the appetite for free software in my country is pretty low, I'll be happy to be the first one around here advocating for the project's adoption in educational environments, and maybe even get my hands dirty in creating a flavour for our own needs. I am not used to make very advanced plannings, so from now on, time will tell what I'll be doing next, but I think I have a pretty consistent starting point. What do you see as the advantages of Skolelinux/Debian Edu? Not a long time ago, I was in the position of configuring and maintaining a LDAP server on some Debian derivative, and I must say it took me a while. A long time ago, I was maintaining a bigger Samba-powered infrastructure, and I must say I spent quite a lot of time on it. I have similar stories about many of the services included with Skolelinux, and the main advantage I see about it is the out-of-the box availability of them, making it quite competitive when it comes to managing a school's network, for example. Of course, there is more to say about Skolelinux than the availability of the software included, its flexibility in various scenarios is something I can't wait to experiment "into the wild" (I only played with virtual machines so far). And I am sure there is a lot more I haven't discovered yet about it, being so new within the project. What do you see as the disadvantages of Skolelinux / Debian Edu? As usual, when it comes to Debian Blends, I see as the biggest disadvantage the lack of a numerous team dedicated to the project. Every day I see the same names in the changelogs, and I have a constantly fear of the bus factor in this story. I'd like to see Debian Edu advertised more as an entry point into the Debian ecosystem, especially amongst newcomers and students. IMHO there are a lot low-hanging fruits in terms of bug squashing, and enough opportunities to get the feeling of the Debian Project's dynamics. Not to mention it's a very fun blend to work on! Derived from the previous statement, is the delay in catching up with the main Debian release and documentation. This is common though to all blends and derivatives, but it's an issue we can all work on. Which free software do you use daily? I can hardly imagine myself spending a day without Vim, since my daily routine covers writing code and hacking configuration files. I am a fan of the Awesome window manager (but I also like the Enlightenment project a lot!), Claws Mail due to its ease of use and very configurable behaviour. Recently I fell in love with Redshift, which helps me get through the night without headaches. Of course, there is much more stuff in this bag, but I'll need a blog on my own for doing this! Which strategy do you believe is the right one to use to get schools to use free software? Well, on this field, I cannot do much more than experiment right now. So, being far from having a recipe for success, I can only assume that:

• schools would like to get rid of proprietary software
• students will love the openness of the system, and will want to experiment with it - maybe we need to harvest the native curiosity of teenagers more?
• there is no "right one" when it comes to strategies, but it would be useful to have some success stories published somewhere, so other can get some inspiration from them (I know I'd promote them!)
• more active promotion - talks, conferences, even small school lectures can do magical things if they encounter at least one person interested. Who knows who that person might be? ;-)

I also see some problems in getting Skolelinux into schools; for example, in our country we have a great deal of corruption issues, so it might be hard(er) to fight against proprietary solutions. Also, people who relied on commercial software for all their lives, would be very hard to convert against their will.

In light of the recent leaks about the NSA's illegal spying, I've decided to go back to using M-x spook output in my email signatures. cypherpunk anthrax John Kerry rail gun security plutonium Guantanamo wire transfer JPL number key military MD5 SRI FIPS140 Uzbekistan

Yesterday I ran in the City2South. It was a beautiful day for it, and I really enjoyed the run. Thanks to generous support of my donors, I raised $252 for the Heart Foundation. My official time was 1:20:41, which I'm really happy with. I'd only ever run 14km on the preceding Tuesday, and I ran that in 1:32:57, so to do this run 12 minutes faster, on a completely different course felt like quite the accomplishment. I also ran personal best times for 5K and 10K. It's hard to believe that the guy who came first ran it in 44 minutes. the course was really nice, except for running up Highgate Hill at kilometre 12. That was a bit harsh, but I managed to run all the way up it, nonetheless. It only hit me this afternoon when I was replaying the course in my mind just how far I ran. My normal 10K course doesn't feel all that long because it loops back on itself a lot, so it's deceptive how much ground I cover. From a technical perspective, the race was done very well. I liked that they had a Facebook app that in real time posted updates when I crossed the start, 5K, 10K and finish lines, and the official results were online by the time I got home. That said, as I write, the website is throwing all sorts of errors when I try to download my official finishing certificate, or see my photos and finish line video. All things considered, it was a pretty nice way to spend a Sunday morning. I was up at 5am to be on the 5:44am ferry from Hawthorne, and back home again by 10am. I'm very keen to try running a half marathon now, but my next run is the 10km Bridge to Brisbane in September. That one will be more interesting because presumably it involves running up the Gateway Bridge, and I'll be pushing Zoe in a jogging stroller. I'm not expecting any personal best times for that one.

Interesting times.. While the big disasters are ongoing, little ones have been spicing up my life lately. A pleasant week by the beach ended with a tropical storm passing over the beach house. I've never experienced this before, and though Andrea was diminished by passing over land, it was still more wind than I've ever seen. I love wind, and this was thrilling, right on the edge of danger but not quite there. At least, if you have sense to stay out of the water. Leaving the beach, I heard of someone who tried to go surfing that day, and drowned. The night before last, I was startled to find nearly an inch of water seeping up from underneath the tile floor of the kitchen. Probably it has something to do with the pressure tank pumping system, which was repaired while I was away, and means I actually have indoor running water here. (Overrated.) This saw me scrambling to close every water valve, and out with a flashlight at 2 am closing the cutoff at the 1000 gallon water reservoir before it all drained into the house. While sopping up dozens of gallons of water from the floor at 3 am probably doesn't sound like fun, I found myself going through the motions elatedly.. Because this means I finally am coming to understand the source of the damp that infests the most earth-sheltered corner of this house. It's not condensation. It's bad plumbing! Then yesterday, I went out to try a dip in the river, stopped by the neighborhood eatery and bait shop, and ended up sitting out on the back deck eating ribs and listening to a band with "possum playboys" in their name (which makes the full name fairly irrelevant), while looking out over the river and the old-timey green metal bridge. Which was unexpected fun, and the kind of thing you have to take in when it happens, but getting stuck in a newly installed hole in my driveway was not. My car was spinning, and I gave up and called it a night. Here's the thing. I could feel my brain working on this stupid "underpowered car is stuck in a small rut" issue all night long. Same mental pathways activating that chew over bugs and design issues. Got up this morning with a set of plans and contingency plans all ready to go. The first one, of jacking it up and putting something under the tire was stymied; it seems I am missing a jack. But the second, of digging out all around the tire, and then filling in with gravel and cat litter (a tip from some offroading website I blearily surfed last night), and then riding the gas while releasing the bake, worked great. All of which is to say, bring em on! But I still prefer my disasters in the form of software bugs.

2 x laptops, 1 x HP microserver, 3 x routers, 1 x Raspberry Pi given to a charity to go to Kenya to help provide Internet and other services for an NGO. The house has the fewest working desktop computers it's ever had - but it is for a good cause.

Somehow, I suspect that 50 / $100 Android tablets that are starting to be common won't be quite as useful in a couple of years as this lot may be today. For those of us that have good access to technology, fast connectivity as a given and computers to give away - maybe it's time to share the benefits of prosperity with others. If nothing else, it is sharing Debian and Raspbian since I made sure that they were all working well with Debian 7 and Raspbian operating systems respectively before they went. The routers were also running OpenWRT - so it's all FLOSS :)

Recently, I ate at the somewhat famous London vegetarian restaurant Indian Veg Bhelpoori House in Islington (often referred to simply as Indian Veg ).

I couldn t help but imagine that the restaurant had hired Emanuel Bronner as their interior decorator.

If all goes well, a new release of dput-ng will hit the archive this week (depending on when I can find time to close the last 2 bigger bugs) - anyone interested in getting a new feature into dput-ng should email me (or file a reportbug bug at dput-ng) Small list of changes so far: * Add per-host loading of command files by partially parsing command line arguments. * Add disallowed_distributions. * Add codename groupping support. * Add codename groups to vital targets, limit security uploads to the right servers (Closes: #708575). * Implement dcut commands for Deb-o-Matic. * Add an override and a unset option to dput which overrules any profile key. This is an experimental option. * Be more precise about our configuration file inheritance in dput(5). * Fix dcut: manpage and help talk about -U and upload by replacing those parts in the text by the upload command (Closes: #699812) * Make the login name determination more portable (Closes: #709831) * Fix Allow to give out dm permissions without using local keyring by * documenting the force option in the man page (Closes: #711057) * Allow uploads to mentors to target every distribution * Add a space in debug s help message. * Fixed a typo (DEBNAME DEBFULLNAME) in the dcut(1) manpage. Thanks, y all!

I've been singing for a long time. The first time I was a member of a choir was when I was around 6-7 years old, and it was as a member of the children's choir 'De Lambertijnen' in Ekeren, Belgium. Not by coincidence, Ekeren is where I grew up. However, I didn't remain a member of 'De Lambertijnen' for very long. After a year or two, I was over the maximum age for members of that choir, and "promoted" to Carmina, another children's choir of the same association. I didn't like that choir as much, though, and only remained a member for about a year or so, before I left that choir; and for a few years, choral music was no longer part of my interests. Then, when I turned sixteen, I was in a school where choral music was part of the curriculum; and through class, I found out that singing in a choir is something I actually love. By that time I was too old to join Carmina again, so I joined the C-koren's youth choir "Cantilene" under Luc Anthonis, instead. Luc is one of Belgium's finest choir conductors, and so I remained a member until my 26th birthday when, again, I was deemed too old to remain a member of that choir. At this point, the next choir in line was "Con Amore", a choir that does not have an age limit, but which in practice consists of mostly people who are retired (or nearly so, at least). As a result, most people who leave Cantilene do not join Con Amore, instead ending their foray into choral music. I was no exception. However, a year and a half (or so) later, the C-koren were extended with a new choir, "Caljent ", who jumpstarted their membership by contacting ex-Cantilene members (me amongst them), inviting them to join this new choir. I have been a member since the first official rehearsal of Caljent , and have always enjoyed it; enough so that when I moved out of Ekeren some five years ago, into a flat in Mechelen (a 30 minute car trip away), I did not quit the choir. I can, however, not deny that since moving out, my connection to Ekeren has become fairly strained, and that there have been times when I felt it difficult to motivate myself into driving all the way there for a rehearsal on friday night. I felt that to be unfair towards the conductor and towards the other members of the choir, and so it is with mixed feelings that I decided a month or so ago to remain a member only until the last rehearsal before the summer break this year. That last rehearsal was today (well, technically yesterday by now); and so, after a "career" of almost 20 years of nearly uninterrupted membership (including one 5-year stint as a member of Cantilene's governing board), I am now no longer a member of the C-koren. That's not to say I won't be singing anymore in fact, I've already joined a different choir whose rehearsal location just happens to be right around the corner from where I live but it does certainly feel weird to be putting an end to my C-koren membership. Ah well, we'll see what the future brings.

I've set up a windows machine yesterday (& today since this takes so long). on my own old laptop. at home. & it's running in my apartment. feels strange after living in windows-free apartments for quite some years. & I'm still not sure how I feel about it. the purpose of resurrecting my old laptop is to run a CPAN smoke tester. there are constant complaints in the perl community about the low amount of test reports from windows installations (& for older distributions, so I'm running CPAN::Reporter::Smoker with 'reverse' => 1, at least once). for the time being, I'm using non-free software to improve free software. let's see how this develops ps: I'm also running a CPAN smoke tester on my raspberry pi (under raspbian with a perlbrewed perl) since a few days. it's a bit slow but well :)

Hello Config::Model::Dpkg project (a Debian source package model based on Config::Model) is partly based on a ParseRec::Descent grammar. This grammar is used to parse the dependency of a Debian source package. This article will show how such a grammar is written, its limitation regarding error handling and how to improve the situation. Debian package main data is described in debian/control file. This file can feature a list of dependencies, i.e. a list of package that must be installed for the package to work. These dependencies are declared in fields like Build-Depends , or Depends as a list of package. For Dpkg model purpose, I needed only to parse one item of a dependency list at a time. This dependency item can be a simple package name: foo or a package name with a version requirement: foo ( > 1.24 ) or a package name with architectures restrictions: foo [alpha amd64 hurd-arm linux-armeb] or both: foo ( > 1.24 ) [alpha amd64 hurd-arm linux-armeb] or a list of alternate choices combining the possibilities above: foo ( > 1.24 ) bar [ linux-any] baz ( << 3.14 ) [ ! hurd-armel !hurd-armeb ] or a variable that is replaced during package build: $ perl-depends Writing a Parse::RecDescent grammar to parse this is relatively straightforward. The first production handles alternate dependencies separated by and raises an error if some text was not consumed by the dependencies:

dependency_item: depend(s /\ /) eofile  

A dependency as explained above is expressed as:

depend: pkg_dep   variable

A variable like $ foo or $ bar -1.24~ is parsed with:

variable: /\$ [\w:\-]+ [\w\.\-~+]*/

This rule handles a package name with optional version or arch restriction:

pkg_dep: pkg_name dep_version(?) arch_restriction(?) 
pkg_name: /[a-z0-9][a-z0-9\+\-\.]+/

The remaining rules are quite simple:

dep_version: '(' oper version ')' 
oper: '<<'   '<='   '='   '>='   '>>'
version: variable   /[\w\.\-~:+]+/
arch_restriction: '[' arch(s) ']'
arch:  /!?[\w-]+/
eofile: /^\Z/

The grammar above works well to parse the dependency. You can test it with this small Perl script:

#!/usr/bin/perl
use strict;
use warnings;
use 5.010 ;
use Parse::RecDescent ;
my $parser = Parse::RecDescent->new(join('',));
my $dep = shift ;
say "parsing '$dep'";
my $ret = $parser->dependency_item($dep) ;
say "result is ", $ret if $ref ;
__DATA__
# insert grammar here !!!

Unfortunately, any error in the optional parts (i.e version requirements and arch restriction) leads to an error message which is not very helpful. The error message only mention that some text could not be parsed:

parsing 'foo ( != 1.24 )   bar'
       ERROR (line 1): Invalid dependency item: Was expecting /\ / but found
                       "( != 1.24 )   bar" instead

or

parsing 'foo [ arm & armel]   bar'
       ERROR (line 1): Invalid dependency item: Was expecting /\ / but found
                       "[ arm & armel]   bar" instead

The problem comes from the fact that version requirements or arch restrictions are optional. For instance if a version requirement has a syntax error, Parse::RecDescent will try to parse it as an arch restriction. This arch restriction rule will also fail and the last terminal ( eofile ) will fail. So the error message does not hint at the actual syntax problem. To generate better error messages, I improved the suggestion made in Parse::RecDescent FAQ. Instead of calling a plain subroutine, I use a sub reference that will store the error messages in a closure. This sub ref is declared in a start-up action. Note that the sub ref explicitly returns undef. I ll explain why later.

 
    my @dep_errors ;
    my $add_error = sub  
        my ($err, $txt) = @_ ;
        push @dep_errors, "$err: '$txt'" ;
        return ;
      ;
 

The following production always fails while ensuring that the error list is reset. This production is always run at the beginning of the dependency parsing:

dependency:   @dep_errors = ();  

Here s the actual dependency production that is run when dependency method is called on the parser. It will return an array ref containing (1, data) if the dependency is valid or (0, errors) otherwise:

dependency: depend(s /\ /) eofile
   
    $return = [ 1 , @ $item[1]  ] ;
   
   
   
    push( @dep_errors, "Cannot parse: '$text'" ) unless @dep_errors ;
    $return =  [ 0, @dep_errors ];
   

The following productions don t change much:

depend: pkg_dep   variable
variable: /\$ [\w:\-]+ [\w\.\-~+]*/
pkg_dep: pkg_name dep_version(?) arch_restriction(?) 
dep_version: '(' oper version ')'

The first rule of this production parses the package name which must be followed by a space, end of string ( or ['. A positive look-ahead assertion is used so only the package name is consumed. If the first rule fails, the second rule provides a meaningful error message. The second rule will match anything which is not a space and create an error message. Since $add_error returns undef, the second rule returns undef and the production fails. So the text stored in the error message is not consumed:

pkg_name: /[a-z0-9][a-z0-9\+\-\.]+(?=\s \Z \( \[)/
      /\S+/   $add_error->("bad package name", $item[1]) ; 

The same trick is used with these productions:

oper: '<<'   '='   '>>'
      /\S+/   $add_error->("bad dependency version operator", $item[1]) ; 
version: variable   /[\w\.\-~:+]+(?=\s \) \Z)/
      /\S+/   $add_error->("bad dependency version", $item[1]) ; 

The action of this production is a little bit more tricky. The action ensures that '!' are either added before all arch or not at all. Otherwise an error message is generated and added to the list of errors:

arch_restriction: '[' osarch(s) ']'
     
        my $mismatch = 0;
        # $ref contains ['!',os,arch] or ['',os,arch]
        my $ref = $item[2] ;
        for (my $i = 0; $i < $#$ref -1 ; $i++ )  
            $mismatch  = ($ref->[$i][0] xor $ref->[$i+1][0]) ;
         
        my @a = map   ($_->[0]   '') . ($_->[1]   '') . $_->[2]   @$ref ;
        if ($mismatch)  
            $add_error->("some names are prepended with '!' while others aren't.", "@a") ;
         
        else  
            $return = 1 ;
         
     

The check above is possible only if the "osarch" production returns an array ref containing something like ('!','linux','any') for "!linux-any' or ('','linux','any') for "linux-any":

osarch: not(?) os(?) arch
     
        $return =  [ $item[1][0], $item[2][0], $item[3] ];
     
      /.?(?=\s \] \Z)/   $add_error->("bad arch specification: ", $item[1]) ;  
not: '!'

Here's the remaining of the grammar:

os: /(any uclibc-linux linux kfreebsd knetbsd etc...)-/
     /\w+/ '-'   $add_error->("bad os in architecture specification", $item[1]) ; 
arch: / (any  alpha amd64  arm\b  arm64  etc... )
        (?=(\]  ))
      /x
        /\w+/   $add_error->("bad arch in architecture specification", $item[1]) ; 
eofile: /^\Z/

That's all for grammar 2.0... Before someone yells: "Show me the message ! ", here are some example of bad dependencies and their error message generated by the parser:

parse 'foo ( != 1.24 )   bar'
result is: 0 bad dependency version operator: '!='
parsing 'foo [ arm & armel]   bar'
result is: 0 bad arch specification: : '&'
parsing 'foo [ arm armel ]   bar [!moo]'
result is: 0 bad arch specification: : ']' bad arch in architecture specification: 'moo'

The 2 first error messages are spot on the actual error. The second one has a false positive (']' is correct) but correctly highlights the wrong arch name ('moo'). Mission accomplished. In order to keep this post (relatively) simple, I've removed the part that actually store parsed data. They don't really matter for error handling. Nevertheless, you may see the whole grammar in Config::Model::Dpkg::Dependency module. All the best
Tagged: Config::Model, debian, dpkg, package, Parse::RecDescent, Perl

Migrating a Debian installation between architectures has always been difficult. The recommended way to crossgrade an i386 Debian to amd64 Debian was to reinstall the system, move over data and configuration. For the more brave, in-place crossgrades usually involved chroots, rescue CDs, a lot of ar p tar xf - data.tar.gz and luck. I have never been brave when it comes to system administration, have done a lot of architecture migrations with reinstallation, and have always taken the opportunity to clear out the contamination that accumulates itself when a system is running for a long time. I would even recommend doing this to most people even now. However, I have a few very ugly systems in place that are still on i386 because I didn t dare going the reinstallation path. Doing in-place crossgrades has become a lot easier since wheezy s release, since once now can have both i386 and amd64 libraries installed in parallel, which allows to replace foo:i386 with foo:amd64 without influencing the other parts of the system. The process is still full of pitfalls:

• apt removes a package before it reinstalls its new counterpart. This results in apt calling dpkg to remove dpkg, and then calling dpkg again to install dpkg. Guess which operation fails and the state of the system after this failure. Same applies to coreutils, which leaves the system without rm, which in turn dpkg of either architecture doesn t like. Using apt-get --download-only install to resolve dependencies and downloading the debs, followed by a traditional dpkg --install solves this issue since multiarch dpkg will replace a package with another one without deinstalling the first one first.
• At least for the process, you need a kernel that can run both 32bit and 64bit binaries for the i386 architecture. AFAIR, setting CONFIG_64BIT, CONFIG_X86_64 and CONFIG_IA32_EMULATION in the kernel configuration takes care of this.
• During the process, apt wants to remove the better part of your system. It is important to not let it do this, as it wants to deinstall essential packages as well.
• It looks like the process is not always exactly reproducible. During the first tries, I found myself without an initrd at all, with an initrd that lacked the ext[234].ko kernel modules, without working e2fstools and in a number of other undesireable states of the system.

I have only tried this yet with a freshly installed minimal wheezy server system. I do not, however, expect surprises when it comes to using this process with real life systems. I will document other pitfalls I have fallen into here at a later time. My minimal wheezy system was running in a KVM VM with its virtual disk as a LVM LV in the host system. I took a snapshot before beginning and used lvconvert --merge numerous time to return my LV to the original state. Be aware that lvconvert --merge removes the snapshot after merging it, so you ll need to re-create the snapshot before trying again. During the process, I discussed things with Paul Tagliamonte, who has done this before, but on a live system and with a slightly more invasive approach. He has blogged about this. Thank you very much, your hints were very helpful. Here is a commented typescript of what I have done. Be warned: This was a lab setting with a rather minimal system. If you re going to try this with a production system, have a backup, or, if you re on snapshottable infrastructure, take snapshots and be prepared to roll back if anything goes wrong. First let s see what we have and save a list of installed packages.

mh@swivel:~$ ssh wheezyarch.zugschlus.de
$ uname -a
Linux wheezyarch 3.9.4-zgsrv2008064 #2 SMP PREEMPT Wed Jun 5 12:57:51 UTC 2013 x86_64 GNU/Linux
$ dpkg --print-architecture
i386
$ dpkg --print-foreign-architectures
$ dpkg --list   grep i386   wc -l
175
$ dpkg --list   grep amd64   wc -l
0
$ sudo dpkg --get-selections   grep install   awk  print $1    sed  s/:.*//;s/$/:amd64
install/;  > get-selections.pre

So we have an i386 system running an x86_64 kernel. Next, we add amd64 as an additional architecture which allows us to install amd64 packages. We download the amd64 packages files. Note that dpkg still considers this an i386 system with amd64 as a foreign arch.

$ sudo dpkg --add-architecture amd64
$ sudo apt-get update
Get:1 http://security.debian.org wheezy/updates Release.gpg [836 B]
( )
Fetched 6.155 kB in 4s (1.400 kB/s)
Reading package lists... Done
$ dpkg --print-architecture
i386
$ dpkg --print-foreign-architectures
amd64
$ dpkg --list   grep i386   wc -l
175
$ dpkg --list   grep amd64   wc -l
0

Next, download everything that is necessary to migrate dpkg and apt from i386 and amd64. We cannot directly apt things as the remove-install cycle used by apt will leave us without working dpkg. One could work around this by un-aring the dpkg.deb and directly forcing the amd64 files upon the system, but I think this approach is much cleaner. apt-get download will not resolve dependices while apt-get --download install does. After the download, dpkg --install the packages. dpkg is not particularly smart about installation order, so Pre-Depends may fail or not. If they fail, dpkg will give a list of deb files that were affected, which is an easy help to finish their installation. One could also choose the easy way (which I did here) and repeat the dpkg --install *.deb command. Since the Pre-Depends will already be installed, the second install run will succeed.

$ sudo apt-get --download-only install dpkg:amd64 apt:amd64
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following extra packages will be installed:
  gcc-4.7-base:amd64 libapt-pkg4.12:amd64 libbz2-1.0:amd64 libc6:amd64
  libgcc1:amd64 liblzma5:amd64 libselinux1:amd64 libstdc++6:amd64
  zlib1g:amd64
Suggested packages:
  aptitude:amd64 synaptic:amd64 wajig:amd64 dpkg-dev:amd64 apt-doc:amd64
  python-apt:amd64 glibc-doc:amd64 locales:amd64
The following packages will be REMOVED:
  apt cron-apt dpkg
The following NEW packages will be installed:
  apt:amd64 dpkg:amd64 gcc-4.7-base:amd64 libapt-pkg4.12:amd64
  libbz2-1.0:amd64 libc6:amd64 libgcc1:amd64 liblzma5:amd64 libselinux1:amd64
  libstdc++6:amd64 zlib1g:amd64
0 upgraded, 11 newly installed, 3 to remove and 0 not upgraded.
Need to get 10,0 MB of archives.
After this operation, 14,9 MB of additional disk space will be used.
Do you want to continue [Y/n]? 
Get:1 http://debian.debian.zugschlus.de/debian/ wheezy/main gcc-4.7-base amd64 4.7.2-5 [144 kB]
( )
Fetched 10,0 MB in 2s (3.535 kB/s)
Download complete and in download only mode
$ sudo dpkg --install /var/cache/apt/archives/*.deb
(Reading database ... 16586 files and directories currently installed.)
Preparing to replace apt 0.9.7.8 (using .../archives/apt_0.9.7.8_amd64.deb) ...
Unpacking replacement apt ...
dpkg: regarding .../dpkg_1.16.10_amd64.deb containing dpkg, pre-dependency problem:
 dpkg pre-depends on libbz2-1.0
dpkg: error processing /var/cache/apt/archives/dpkg_1.16.10_amd64.deb (--install):
 pre-dependency problem - not installing dpkg
Selecting previously unselected package gcc-4.7-base:amd64.
( )
Errors were encountered while processing:
 /var/cache/apt/archives/dpkg_1.16.10_amd64.deb
$ sudo dpkg --install /var/cache/apt/archives/*.deb
(Reading database ... 16905 files and directories currently installed.)
Preparing to replace apt 0.9.7.8 (using .../archives/apt_0.9.7.8_amd64.deb) ...
Unpacking replacement apt ...
( )
$

From dpkg s point of view, the system is now already amd64, with i386 being a foreign arch. However, the majory of packages is still i386.

$ dpkg --print-architecture
amd64
$ dpkg --print-foreign-architectures
i386
$ dpkg --list   grep i386   wc -l
173
$ dpkg --list   grep amd64   wc -l
11
$ 

The apt resolver is currently in a very bad broken state since the system is missing most essential packages in its native architecture. This is not easily solved by apt-get -f install, as this would zap most of the existing system . We let apt-get --download-only -f install download the packages that it wants to replace with its amd64 counterparts and their dependencies, and, again, use dpkg --install *.deb to install them.

$ sudo apt-get --download-only -f install
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Correcting dependencies... Done
The following packages were automatically installed and are no longer required:
  cpio gettext-base:i386 klibc-utils libapt-inst1.5 libasprintf0c2:i386
  libcurl3-gnutls:i386 libfreetype6:i386 libfuse2:i386 libklibc
  libreadline5:i386
Use  apt-get autoremove  to remove them.
The following extra packages will be installed:
  acpid aide bsd-mailx cpio cron curl daemon dctrl-tools exim4-base
  exim4-daemon-light initscripts insserv kbd klibc-utils less libbsd0
  libcomerr2 libcurl3 libdb5.1 libexpat1 libgcrypt11 libgdbm3 libgnutls26
  libgpg-error0 libgssapi-krb5-2 libidn11 libk5crypto3 libkeyutils1 libklibc
  libkmod2 libkrb5-3 libkrb5support0 libldap-2.4-2 liblockfile1 libncursesw5
  libnewt0.52 libp11-kit0 libpam-modules libpam0g libpcre3 libpopt0
  libreadline6 librtmp0 libsasl2-2 libslang2 libsqlite3-0 libssh2-1
  libssl1.0.0 libtasn1-3 libterm-readkey-perl libtinfo5 openssl perl
  perl-base python2.7 python2.7-minimal sysvinit-utils whiptail
Suggested packages:
  libarchive1 anacron logrotate checksecurity debtags mail-reader eximon4
  exim4-doc-html exim4-doc-info spf-tools-perl swaks bootchart2 rng-tools
  krb5-doc krb5-user libpam-doc perl-doc make python2.7-doc binutils
  binfmt-support bootlogd sash
Recommended packages:
  exim4 postfix mail-transport-agent psmisc mailx ca-certificates
  krb5-locales libgpm2 libfribidi0 libsasl2-modules libpng12-0
The following packages will be REMOVED:
  acpid:i386 aide:i386 aptitude:i386 bsd-mailx:i386 cpio:i386 cron:i386
  curl:i386 daemon:i386 dctrl-tools:i386 debsecan dmsetup:i386 e2fsprogs:i386
  exim4-base:i386 exim4-daemon-light:i386 git:i386 grub-common:i386
  grub-pc:i386 grub-pc-bin:i386 grub2-common:i386 ifupdown:i386
  initramfs-tools initscripts:i386 insserv:i386 ippl:i386 jed:i386 kbd:i386
  klibc-utils:i386 less:i386 libdevmapper-event1.02.1:i386
  libdevmapper1.02.1:i386 libklibc:i386 libnewt0.52:i386
  libparted0debian1:i386 libterm-readkey-perl:i386 lsof:i386 lvm2:i386
  molly-guard ntp:i386 openssh-server:i386 openssl:i386 parted:i386 perl:i386
  perl-base:i386 procps:i386 python-apt:i386 python2.7:i386
  python2.7-minimal:i386 rsyslog:i386 sysvinit:i386 sysvinit-utils:i386
  udev:i386 util-linux:i386 whiptail:i386
The following NEW packages will be installed:
  acpid aide bsd-mailx cpio cron curl daemon dctrl-tools exim4-base
  exim4-daemon-light initscripts insserv kbd klibc-utils less libbsd0
  libcomerr2 libcurl3 libdb5.1 libexpat1 libgcrypt11 libgdbm3 libgnutls26
  libgpg-error0 libgssapi-krb5-2 libidn11 libk5crypto3 libkeyutils1 libklibc
  libkmod2 libkrb5-3 libkrb5support0 libldap-2.4-2 liblockfile1 libncursesw5
  libnewt0.52 libp11-kit0 libpam-modules libpam0g libpcre3 libpopt0
  libreadline6 librtmp0 libsasl2-2 libslang2 libsqlite3-0 libssh2-1
  libssl1.0.0 libtasn1-3 libterm-readkey-perl libtinfo5 openssl perl
  perl-base python2.7 python2.7-minimal sysvinit-utils whiptail
0 upgraded, 58 newly installed, 53 to remove and 0 not upgraded.
Need to get 23,4 MB of archives.
After this operation, 17,5 MB disk space will be freed.
Do you want to continue [Y/n]? Y
Get:1 http://security.debian.org/debian-security/ wheezy/updates/main libgnutls26 amd64 2.12.20-7 [619 kB]
( )
Fetched 23,4 MB in 11s (2.038 kB/s)                                           
Download complete and in download only mode
$ sudo dpkg --install /var/cache/apt/archives/*.deb
(Reading database ... 16905 files and directories currently installed.)
Preparing to replace acpid 1:2.0.16-1+deb7u1 (using .../acpid_1%3a2.0.16-1+deb7u1_amd64.deb) ...
( )
Selecting previously unselected package libpam-modules:amd64.
dpkg: regarding .../libpam-modules_1.1.3-7.1_amd64.deb containing libpam-modules:amd64, pre-dependency problem:
 libpam-modules pre-depends on libdb5.1
  libdb5.1:amd64 is unpacked, but has never been configured.
dpkg: error processing /var/cache/apt/archives/libpam-modules_1.1.3-7.1_amd64.deb (--install):
 pre-dependency problem - not installing libpam-modules:amd64
Selecting previously unselected package libpcre3:amd64.
Unpacking libpcre3:amd64 (from .../libpcre3_1%3a8.30-5_amd64.deb) ...
( )
Errors were encountered while processing:
 /var/cache/apt/archives/libpam-modules_1.1.3-7.1_amd64.deb
$ sudo dpkg --install /var/cache/apt/archives/libpam-modules_1.1.3-7.1_amd64.deb
(Reading database ... 17007 files and directories currently installed.)
Unpacking libpam-modules:amd64 (from .../libpam-modules_1.1.3-7.1_amd64.deb) ...
Setting up libpam-modules:amd64 (1.1.3-7.1) ...
$ sudo apt-get clean
$ dpkg --print-architecture
amd64
$ dpkg --print-foreign-architectures
i386
$ dpkg --list   grep i386   wc -l
151
$ dpkg --list   grep amd64   wc -l
66
$ 

The concluding apt-get clean prevents packages from being reinstalled again in the next dpkg --install *.deb run. Now, the apt resolver is kind of fixed, but apt will still want to remove most of the system. I haven t found a way to get out of this mess short of allowing apt to de-install those packages and to manually install their amd64 counterparts later. First, we see what apt wants to do, and paste the The following packages will be removed part of apt-get s output into a sed expression which fixes the architecture strings for us so that we can use the resulting file as input for the following installation procedure. After that, we let apt-get do what itself considers a bad thing and requires us to type a consent sentence. The key is that this deinstallation of essential packages breaks the system, but not apt and dpkg, which allows us to un-break the system afterwards.

$ sudo apt-get -f install
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Correcting dependencies... Done
The following packages were automatically installed and are no longer required:
  gettext-base:i386 libapt-inst1.5 libasprintf0c2:i386 libcurl3-gnutls:i386
  libfreetype6:i386 libfuse2:i386 libreadline5:i386
Use  apt-get autoremove  to remove them.
The following extra packages will be installed:
  sysvinit-utils:i386
Suggested packages:
  bootlogd:i386 sash:i386
The following packages will be REMOVED:
  adduser aide-common aptitude:i386 bsd-mailx console-common console-data
  console-log cron curl debian-goodies debsecan dmsetup:i386 e2fsprogs:i386
  exim4-base exim4-config exim4-daemon-light git:i386 grub-common:i386
  grub-pc:i386 grub-pc-bin:i386 grub2-common:i386 ifupdown:i386
  initramfs-tools initscripts ippl:i386 jed:i386 libcurl3
  libdevmapper-event1.02.1:i386 libdevmapper1.02.1:i386 liberror-perl
  libfile-find-rule-perl libnumber-compare-perl libparted0debian1:i386
  libswitch-perl libterm-readkey-perl libterm-readline-perl-perl
  libtext-glob-perl libtimedate-perl locales lsof:i386 lvm2:i386 molly-guard
  ntp:i386 openssh-client:i386 openssh-server:i386 openssl openssl-blacklist
  openssl-blacklist-extra parted:i386 perl perl-modules procps:i386
  python-apt:i386 rsyslog:i386 stow sysv-rc sysvinit:i386 sysvinit-utils
  tzdata ucf udev:i386 util-linux:i386
The following NEW packages will be installed:
  sysvinit-utils:i386
WARNING: The following essential packages will be removed.
This should NOT be done unless you know exactly what you are doing!
  e2fsprogs:i386 util-linux:i386 (due to e2fsprogs:i386) sysvinit:i386
  sysvinit-utils tzdata (due to util-linux:i386)
0 upgraded, 1 newly installed, 62 to remove and 0 not upgraded.
Need to get 97,1 kB of archives.
After this operation, 131 MB disk space will be freed.
You are about to do something potentially harmful.
To continue type in the phrase  Yes, do as I say!  ? (abort with Ctrl-C)
$ sed  s/:i386//g  > removedpkg (paste  The following packages will be REMOVED:  stanza here and
type Ctrl-D afterwards)
  adduser aide-common aptitude:i386 bsd-mailx console-common console-data
  console-log cron curl debian-goodies debsecan dmsetup:i386 e2fsprogs:i386
  exim4-base exim4-config exim4-daemon-light git:i386 grub-common:i386
  grub-pc:i386 grub-pc-bin:i386 grub2-common:i386 ifupdown:i386
  initramfs-tools initscripts ippl:i386 jed:i386 libcurl3
  libdevmapper-event1.02.1:i386 libdevmapper1.02.1:i386 liberror-perl
  libfile-find-rule-perl libnumber-compare-perl libparted0debian1:i386
  libswitch-perl libterm-readkey-perl libterm-readline-perl-perl
  libtext-glob-perl libtimedate-perl locales lsof:i386 lvm2:i386 molly-guard
  ntp:i386 openssh-client:i386 openssh-server:i386 openssl openssl-blacklist
  openssl-blacklist-extra parted:i386 perl perl-modules procps:i386
  python-apt:i386 rsyslog:i386 stow sysv-rc sysvinit:i386 sysvinit-utils
  tzdata ucf udev:i386 util-linux:i386
$ cat removedpkg 
  adduser aide-common aptitude bsd-mailx console-common console-data
  console-log cron curl debian-goodies debsecan dmsetup e2fsprogs
  exim4-base exim4-config exim4-daemon-light git grub-common
  grub-pc grub-pc-bin grub2-common ifupdown
  initramfs-tools initscripts ippl jed libcurl3
  libdevmapper-event1.02.1 libdevmapper1.02.1 liberror-perl
  libfile-find-rule-perl libnumber-compare-perl libparted0debian1
  libswitch-perl libterm-readkey-perl libterm-readline-perl-perl
  libtext-glob-perl libtimedate-perl locales lsof lvm2 molly-guard
  ntp openssh-client openssh-server openssl openssl-blacklist
  openssl-blacklist-extra parted perl perl-modules procps
  python-apt rsyslog stow sysv-rc sysvinit sysvinit-utils
  tzdata ucf udev util-linux
$ sudo apt-get -f install
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Correcting dependencies... Done
The following packages were automatically installed and are no longer required:
  gettext-base:i386 libapt-inst1.5 libasprintf0c2:i386 libcurl3-gnutls:i386
  libfreetype6:i386 libfuse2:i386 libreadline5:i386
Use  apt-get autoremove  to remove them.
The following extra packages will be installed:
  sysvinit-utils:i386
Suggested packages:
  bootlogd:i386 sash:i386
The following packages will be REMOVED:
  adduser aide-common aptitude:i386 bsd-mailx console-common console-data
  console-log cron curl debian-goodies debsecan dmsetup:i386 e2fsprogs:i386
  exim4-base exim4-config exim4-daemon-light git:i386 grub-common:i386
  grub-pc:i386 grub-pc-bin:i386 grub2-common:i386 ifupdown:i386
  initramfs-tools initscripts ippl:i386 jed:i386 libcurl3
  libdevmapper-event1.02.1:i386 libdevmapper1.02.1:i386 liberror-perl
  libfile-find-rule-perl libnumber-compare-perl libparted0debian1:i386
  libswitch-perl libterm-readkey-perl libterm-readline-perl-perl
  libtext-glob-perl libtimedate-perl locales lsof:i386 lvm2:i386 molly-guard
  ntp:i386 openssh-client:i386 openssh-server:i386 openssl openssl-blacklist
  openssl-blacklist-extra parted:i386 perl perl-modules procps:i386
  python-apt:i386 rsyslog:i386 stow sysv-rc sysvinit:i386 sysvinit-utils
  tzdata ucf udev:i386 util-linux:i386
The following NEW packages will be installed:
  sysvinit-utils:i386
WARNING: The following essential packages will be removed.
This should NOT be done unless you know exactly what you are doing!
  e2fsprogs:i386 util-linux:i386 (due to e2fsprogs:i386) sysvinit:i386
  sysvinit-utils tzdata (due to util-linux:i386)
0 upgraded, 1 newly installed, 62 to remove and 0 not upgraded.
Need to get 97,1 kB of archives.
After this operation, 131 MB disk space will be freed.
You are about to do something potentially harmful.
To continue type in the phrase  Yes, do as I say! 
 ?] Yes, do as I say! (actually type this!)
Get:1 http://debian.debian.zugschlus.de/debian/ wheezy/main sysvinit-utils i386 2.88dsf-41 [97,1 kB]
Fetched 97,1 kB in 0s (687 kB/s)    
(Reading database ... 17050 files and directories currently installed.)
Removing aide-common ...
( )
dpkg: warning: overriding problem because --force enabled:
 This is an essential package - it should not be removed.
Removing e2fsprogs ...
Removing sysv-rc ...
dpkg: warning: overriding problem because --force enabled:
 This is an essential package - it should not be removed.
Removing sysvinit ...
dpkg: warning: overriding problem because --force enabled:
 This is an essential package - it should not be removed.
Removing sysvinit-utils ...
dpkg: warning: overriding problem because --force enabled:
 This is an essential package - it should not be removed.
Removing ucf ...
dpkg: warning: overriding problem because --force enabled:
 This is an essential package - it should not be removed.
dpkg: warning: overriding problem because --force enabled:
 This is an essential package - it should not be removed.
dpkg: warning: overriding problem because --force enabled:
 This is an essential package - it should not be removed.
dpkg: warning: overriding problem because --force enabled:
 This is an essential package - it should not be removed.
dpkg: warning: overriding problem because --force enabled:
 This is an essential package - it should not be removed.
Removing libdevmapper1.02.1:i386 ...
Removing libswitch-perl ...
Removing perl ...
dpkg: warning: overriding problem because --force enabled:
 This is an essential package - it should not be removed.
Removing dmsetup ...
Removing perl-modules ...
dpkg: warning: overriding problem because --force enabled:
 This is an essential package - it should not be removed.
Removing util-linux ...
Removing tzdata ...
Processing triggers for mime-support ...
Selecting previously unselected package sysvinit-utils.
(Reading database ... 9802 files and directories currently installed.)
Unpacking sysvinit-utils (from .../sysvinit-utils_2.88dsf-41_i386.deb) ...
Setting up sysvinit-utils (2.88dsf-41) ...
$ sudo apt-get install $(cat removedpkg)
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libasprintf0c2:i386 libcurl3-gnutls:i386 libfreetype6:i386 libfuse2:i386
  libreadline5:i386
Use  apt-get autoremove  to remove them.
The following extra packages will be installed:
  e2fslibs gettext-base libapt-inst1.5 libasprintf0c2 libattr1 libblkid1
  libboost-iostreams1.49.0 libcap2 libcurl3-gnutls libcwidget3 libedit2
  libept1.4.12 libfreetype6 libfuse2 libgpm2 libncurses5 libopts25 libprocps0
  libreadline5 libsepol1 libsigc++-2.0-0c2a libss2 libudev0 libuuid1 libwrap0
  libxapian22 logrotate
Suggested packages:
  liblocale-gettext-perl tasksel debtags unicode-data anacron checksecurity
  popularity-contest xdg-utils zenity gpart e2fsck-static mail-reader eximon4
  exim4-doc-html exim4-doc-info spf-tools-perl swaks git-daemon-run
  git-daemon-sysvinit git-doc git-el git-arch git-cvs git-svn git-email
  git-gui gitk gitweb multiboot-doc grub-emu xorriso desktop-base
  isc-dhcp-client dhcp-client ppp rdnssd net-tools gpm libcwidget-dev fuse
  libparted0-dev libparted0-i18n xapian-tools ntp-doc ssh-askpass libpam-ssh
  keychain monkeysphere rssh ufw parted-doc perl-doc make libpod-plainer-perl
  python-apt-dbg python-gtk2 python-vte python-apt-doc rsyslog-mysql
  rsyslog-pgsql rsyslog-doc rsyslog-gnutls rsyslog-gssapi rsyslog-relp
  doc-base sysv-rc-conf bum bootlogd sash util-linux-locales dosfstools
Recommended packages:
  aptitude-doc-en aptitude-doc apt-xapian-index libparse-debianchangelog-perl
  exim4 postfix mail-transport-agent psmisc mailx patch rsync ssh-client
  os-prober busybox busybox-initramfs busybox-static ca-certificates
  uuid-runtime xauth ncurses-term iso-codes usbutils
The following packages will be REMOVED:
  gettext-base:i386 libboost-iostreams1.49.0:i386 libcwidget3:i386
  libept1.4.12:i386 libopts25:i386 libxapian22:i386 logrotate:i386
  sysvinit-utils:i386
The following NEW packages will be installed:
  adduser aide-common aptitude bsd-mailx console-common console-data
  console-log cron curl debian-goodies debsecan dmsetup e2fslibs e2fsprogs
  exim4-base exim4-config exim4-daemon-light gettext-base git grub-common
  grub-pc grub-pc-bin grub2-common ifupdown initramfs-tools initscripts ippl
  jed libapt-inst1.5 libasprintf0c2 libattr1 libblkid1
  libboost-iostreams1.49.0 libcap2 libcurl3 libcurl3-gnutls libcwidget3
  libdevmapper-event1.02.1 libdevmapper1.02.1 libedit2 libept1.4.12
  liberror-perl libfile-find-rule-perl libfreetype6 libfuse2 libgpm2
  libncurses5 libnumber-compare-perl libopts25 libparted0debian1 libprocps0
  libreadline5 libsepol1 libsigc++-2.0-0c2a libss2 libswitch-perl
  libterm-readkey-perl libterm-readline-perl-perl libtext-glob-perl
  libtimedate-perl libudev0 libuuid1 libwrap0 libxapian22 locales logrotate
  lsof lvm2 molly-guard ntp openssh-client openssh-server openssl
  openssl-blacklist openssl-blacklist-extra parted perl perl-modules procps
  python-apt rsyslog stow sysv-rc sysvinit sysvinit-utils tzdata ucf udev
  util-linux
WARNING: The following essential packages will be removed.
This should NOT be done unless you know exactly what you are doing!
  sysvinit-utils:i386
0 upgraded, 89 newly installed, 8 to remove and 0 not upgraded.
Need to get 55.3 MB of archives.
After this operation, 134 MB of additional disk space will be used.
You are about to do something potentially harmful.
To continue type in the phrase  Yes, do as I say! 
 ?] Yes, do as I say! (actually type this!)
Get:1 http://debian.debian.zugschlus.de/debian/ wheezy/main e2fslibs amd64 1.42.5-1.1 [197 kB]
( )
Fetched 55.3 MB in 20s (2648 kB/s)                                            
perl: warning: Setting locale failed.
( )

This process may re-ask some debconf questions that you have already answered during initial system setup. I find it comforting to actually see that my answers were preserved, but you can always export DEBIAN_FRONTEND=noninteractive if you want installation to be silent. If you know how this step can be done more elegantly, please comment. We now, finally, have the resolver in a consistent state.

$ sudo apt-get -f install
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libasprintf0c2:i386 libcurl3-gnutls:i386 libfreetype6:i386 libfuse2:i386
  libreadline5:i386
Use  apt-get autoremove  to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
$ dpkg --print-architecture
amd64
$ dpkg --print-foreign-architectures
i386
$ dpkg --list   grep i386   wc -l
121
$ dpkg --list   grep amd64   wc -l
119
$ 

Now we can force-crossgrade all i386 packages that are still left on the system. Again, we use the apt-get --download install, dpkg --install stunt as coreutils gets crossgraded at this step and dpkg is less than happy if it finds itself without /bin/rm. Remember, with --download, nothing is actually removed during this step even if apt-get claims to remove things. Apt will also complain that many of these packages are already installed. Those are libs that were pulled in previously. The first dpkg --install run in this step will complain about gazillions of dependency problems, which will all be resolved in concluding apt-get -f install after the second dpkg --install run, this time a manual one.

$ sudo apt-get --download-only install $(dpkg --list   awk  if( $1 ==  ii  && $4 ==
 i386  )   print $2     sed  s/:i386// )
Reading package lists... Done
Building dependency tree       
Reading state information... Done
( )
The following packages were automatically installed and are no longer required:
  libasprintf0c2:i386 libcurl3-gnutls:i386 libfreetype6:i386 libfuse2:i386
  libreadline5:i386
Use  apt-get autoremove  to remove them.
Suggested packages:
  powermgmt-base bash-doc bzip2-doc diffutils-doc wdiff mlocate locate
  gnupg-doc xloadimage imagemagick eog libpcsclite1 iproute-doc resolvconf
  avahi-autoipd nfs-common ncompress indent
Recommended packages:
  bsdmainutils gnupg-curl libatm1
The following packages will be REMOVED:
  anacron:i386 apt-utils:i386 base-files:i386 base-passwd:i386 bash:i386
( )
The following NEW packages will be installed:
  anacron apt-utils base-files base-passwd bash bsdutils busybox bzip2
( )
0 upgraded, 56 newly installed, 49 to remove and 0 not upgraded.
Need to get 24,1 MB of archives.
After this operation, 2.030 kB of additional disk space will be used.
Do you want to continue [Y/n]? y
Get:1 http://debian.debian.zugschlus.de/debian/ wheezy/main kmod amd64 9-3 [60,5 kB]
( )
Fetched 24,1 MB in 11s (2.120 kB/s)                                           
Download complete and in download only mode
$ sudo dpkg --install /var/cache/apt/archives/*.deb
(Reading database ... 17098 files and directories currently installed.)
Preparing to replace adduser 3.113+nmu3 (using .../adduser_3.113+nmu3_all.deb) ...
Unpacking replacement adduser ...
( )
Errors were encountered while processing:
 /var/cache/apt/archives/bash_4.2+dfsg-0.1_amd64.deb
 /var/cache/apt/archives/coreutils_8.13-3.5_amd64.deb
 initscripts
 lvm2
 procps
 rsyslog
 sysvinit
 sysv-rc
 udev
 util-linux
 aide-common
 dmsetup
 e2fsprogs
 ifupdown
 initramfs-tools
 libdevmapper1.02.1:amd64
 libdevmapper-event1.02.1:amd64
 libparted0debian1:amd64
 molly-guard
 openssh-server
 parted
 grub-common
 grub-pc
 grub-pc-bin
 grub2-common
$ sudo dpkg --install /var/cache/apt/archives/bash_4.2+dfsg-0.1_amd64.deb
/var/cache/apt/archives/coreutils_8.13-3.5_amd64.deb
(Reading database ... 17129 files and directories currently installed.)
Preparing to replace bash 4.2+dfsg-0.1 (using .../bash_4.2+dfsg-0.1_amd64.deb) ...
Unpacking replacement bash ...
Preparing to replace coreutils 8.13-3.5 (using .../coreutils_8.13-3.5_amd64.deb) ...
Unpacking replacement coreutils ...
Setting up bash (4.2+dfsg-0.1) ...
update-alternatives: using /usr/share/man/man7/bash-builtins.7.gz to provide /usr/share/man/man7/builtins.7.gz
(builtins.7.gz) in auto mode
Setting up coreutils (8.13-3.5) ...
$ sudo apt-get -f install
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Correcting dependencies... Done
The following packages were automatically installed and are no longer required:
  libasprintf0c2:i386 libcurl3-gnutls:i386 libfreetype6:i386 libfuse2:i386
  libreadline5:i386
Use  apt-get autoremove  to remove them.
The following extra packages will be installed:
  sysvinit-utils
Suggested packages:
  bootlogd sash
The following packages will be REMOVED:
  libslang2-modules:i386 sysvinit-utils:i386
The following NEW packages will be installed:
  sysvinit-utils
WARNING: The following essential packages will be removed.
This should NOT be done unless you know exactly what you are doing!
  sysvinit-utils:i386
0 upgraded, 1 newly installed, 2 to remove and 0 not upgraded.
23 not fully installed or removed.
Need to get 0 B/99,5 kB of archives.
After this operation, 328 kB disk space will be freed.
You are about to do something potentially harmful.
To continue type in the phrase  Yes, do as I say! 
 ?] Yes, do as I say! (actually type this!)
dpkg: warning: overriding problem because --force enabled:
 This is an essential package - it should not be removed.
(Reading database ... 17129 files and directories currently installed.)
Removing sysvinit-utils ...
Selecting previously unselected package sysvinit-utils.
(Reading database ... 17105 files and directories currently installed.)
Unpacking sysvinit-utils (from .../sysvinit-utils_2.88dsf-41_amd64.deb) ...
Setting up sysvinit-utils (2.88dsf-41) ...
Setting up sysv-rc (2.88dsf-41) ...
Setting up initscripts (2.88dsf-41) ...
Setting up util-linux (2.20.1-5.3) ...
Setting up e2fsprogs (1.42.5-1.1) ...
Setting up sysvinit (2.88dsf-41) ...
sysvinit: restarting... done.
(Reading database ... 17129 files and directories currently installed.)
Removing libslang2-modules:i386 ...
Setting up ifupdown (0.7.8) ...
Setting up procps (1:3.3.3-3) ...
[ ok ] Setting kernel variables ... /etc/sysctl.conf...done.
Setting up udev (175-7.2) ...
[ ok ] Stopping the hotplug events dispatcher: udevd.
[ ok ] Starting the hotplug events dispatcher: udevd.
update-initramfs: deferring update (trigger activated)
Setting up rsyslog (5.8.11-3) ...
[ ok ] Stopping enhanced syslogd: rsyslogd.
[ ok ] Starting enhanced syslogd: rsyslogd.
Setting up aide-common (0.15.1-8) ...
Setting up initramfs-tools (0.109.1) ...
update-initramfs: deferring update (trigger activated)
Setting up openssh-server (1:6.0p1-4) ...
[ ok ] Restarting OpenBSD Secure Shell server: sshd.
Setting up molly-guard (0.4.5-1) ...
Setting up libdevmapper1.02.1:amd64 (2:1.02.74-7) ...
Setting up libdevmapper-event1.02.1:amd64 (2:1.02.74-7) ...
Setting up libparted0debian1:amd64 (2.3-12) ...
Setting up grub-common (1.99-27+deb7u1) ...
Setting up grub2-common (1.99-27+deb7u1) ...
Setting up grub-pc-bin (1.99-27+deb7u1) ...
Setting up grub-pc (1.99-27+deb7u1) ...
Installation finished. No error reported.
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-3.9.4-zgsrv2008064
Found initrd image: /boot/initrd.img-3.9.4-zgsrv2008064
done
Setting up parted (2.3-12) ...
Setting up dmsetup (2:1.02.74-7) ...
update-initramfs: deferring update (trigger activated)
Setting up lvm2 (2.02.95-7) ...
[ ok ] Setting up LVM Volume Groups...done.
update-initramfs: deferring update (trigger activated)
Processing triggers for initramfs-tools ...
update-initramfs: Generating /boot/initrd.img-3.9.4-zgsrv2008064
Found 12 processes using old versions of upgraded files
( )
$ sudo apt-get -f install
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libasprintf0c2:i386 libcurl3-gnutls:i386 libfreetype6:i386 libfuse2:i386
  libreadline5:i386
Use  apt-get autoremove  to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
$ dpkg --print-architecture
amd64
$ dpkg --print-foreign-architectures
i386
$ dpkg --list   grep i386   wc -l
72
$ dpkg --list   grep amd64   wc -l
175
$ 

We have completed the actual crossgrade. All non-multiarch packages are now amd64. The resolver is now fine as well. At this current state, all i386 packages that are still installed should be unneeded libs. We can safely nuke them. Careful minds may inspect the list of packages to be removed for important or non-lib items. After completion of the command, a second call of the same command verifies that we were successful.

$ sudo apt-get remove $(dpkg --list   awk  if( $1 ==  ii  && $4 ==  i386  )   print $2
  )
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages will be REMOVED:
  e2fslibs:i386 gcc-4.7-base:i386 libacl1:i386 libapt-inst1.5:i386
  libapt-pkg4.12:i386 libasprintf0c2:i386 libattr1:i386 libblkid1:i386
  libbsd0:i386 libbz2-1.0:i386 libc6:i386 libcap2:i386 libcomerr2:i386
  libcurl3:i386 libcurl3-gnutls:i386 libdb5.1:i386 libedit2:i386
  libexpat1:i386 libfreetype6:i386 libfuse2:i386 libgcc1:i386
  libgcrypt11:i386 libgdbm3:i386 libgnutls26:i386 libgpg-error0:i386
  libgpm2:i386 libgssapi-krb5-2:i386 libidn11:i386 libk5crypto3:i386
  libkeyutils1:i386 libkmod2:i386 libkrb5-3:i386 libkrb5support0:i386
  libldap-2.4-2:i386 liblockfile1:i386 liblzma5:i386 libmagic1:i386
  libncurses5:i386 libncursesw5:i386 libp11-kit0:i386 libpam-modules:i386
  libpam0g:i386 libpci3:i386 libpcre3:i386 libpng12-0:i386 libpopt0:i386
  libprocps0:i386 libreadline5:i386 libreadline6:i386 librtmp0:i386
  libsasl2-2:i386 libselinux1:i386 libsemanage1:i386 libsepol1:i386
  libsigc++-2.0-0c2a:i386 libslang2:i386 libsqlite3-0:i386 libss2:i386
  libssh2-1:i386 libssl1.0.0:i386 libstdc++6:i386 libtasn1-3:i386
  libtinfo5:i386 libudev0:i386 libusb-0.1-4:i386 libustr-1.0-1:i386
  libuuid1:i386 libwrap0:i386 linux-image-3.9.4-zgsrv2008064:i386 zlib1g:i386
0 upgraded, 0 newly installed, 70 to remove and 0 not upgraded.
After this operation, 67,5 MB disk space will be freed.
Do you want to continue [Y/n]? y
(Reading database ... 17111 files and directories currently installed.)
Removing e2fslibs:i386 ...
( )
$ sudo apt-get remove $(dpkg --list   awk  if( $1 ==  ii  && $4 ==  i386  )   print $2
  )
Reading package lists... Done
Building dependency tree       
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
$ dpkg --print-architecture
amd64
$ dpkg --print-foreign-architectures
i386
$ dpkg --list   grep i386   wc -l
70
$ dpkg --list   grep amd64   wc -l
175
$ 

To finally make the packages really vanish from the system, we purge all packages that dpkg --list still reports in state rc , which means removed, configuration still present . Thankfully, dpkg seems to handle the case where a dpkg-conffile belongs to a transitioned package gracefully.

$ sudo dpkg --purge $(dpkg --list   awk  if ($1 ==  rc )   print $2  )
(Reading database ... 15868 files and directories currently installed.)
Removing e2fslibs:i386 ...
Purging configuration files for e2fslibs:i386 ...
( )
$ dpkg --print-architecture
amd64
$ dpkg --print-foreign-architectures
i386
$ dpkg --list   grep i386   wc -l
0
$ dpkg --list   grep amd64   wc -l
175
$ 

We now verify that all packages we have are either arch all or arch amd64.

$ dpkg --list   grep -v  \(amd64 all\) 
Desired=Unknown/Install/Remove/Purge/Hold
  Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
 / Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
 / Name                            Version                   Architecture Description
+++-===============================-=========================-============-========================================================================

As I found myself suddenly without e2fsprogs during one of my experiments, I check for e2fsprogs being present. If this package is missing, you ll only find out after rebooting.

$ dpkg --list e2fsprogs
Desired=Unknown/Install/Remove/Purge/Hold
  Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
 / Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
 / Name           Version      Architecture Description
+++-==============-============-============-=================================
ii  e2fsprogs      1.42.5-1.1   amd64        ext2/ext3/ext4 file system utilit

My locally built amd64 kernel with 32 bit support was an arch i386 package as well, so it got zapped in the migration process. Replace it with a real amd64 kernel. This step will vary if you use Debian kernels. Do not forget the firmwares.

$ sudo apt-get -t wheezy-zg-experimental install kernel-image-zgserver linux-firmware-image
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following extra packages will be installed:
  cpio initramfs-tools kernel-image-zgsrv20080 klibc-utils libklibc
  linux-image-3.9.4-zgsrv20080
Suggested packages:
  libarchive1
The following NEW packages will be installed:
  cpio initramfs-tools kernel-image-zgserver kernel-image-zgsrv20080
  klibc-utils libklibc linux-firmware-image linux-image-3.9.4-zgsrv20080
0 upgraded, 8 newly installed, 0 to remove and 0 not upgraded.
Need to get 11,2 MB of archives.
After this operation, 30,5 MB of additional disk space will be used.
Do you want to continue [Y/n]? 
Get:1 http://zg20110.debian.zugschlus.de/ wheezy-zg-experimental/main linux-image-3.9.4-zgsrv20080 amd64
3.9.4.20130605.0 [10,4 MB]
( )

I now make sure that the initrd I have built contains all file system modules and is of the right architecture:

$ cd /tmp
$ < /boot/initrd.img-3.9.4-zgsrv20080 gunzip   cpio -i
32053 blocks
$ find . -name  *ext*.ko 
./lib/modules/3.9.4-zgsrv20080/kernel/fs/ext3/ext3.ko
./lib/modules/3.9.4-zgsrv20080/kernel/fs/ext2/ext2.ko
./lib/modules/3.9.4-zgsrv20080/kernel/fs/ext4/ext4.ko
$ file ./lib/modules/3.9.4-zgsrv20080/kernel/fs/ext4/ext4.ko
./lib/modules/3.9.4-zgsrv20080/kernel/fs/ext4/ext4.ko: ELF 64-bit LSB relocatable, x86-64, version 1 (SYSV),
BuildID[sha1]=0x259a642448805c9597932ee25c62c8e6a00a32ad, not stripped
$ cd

As the last step, remove i386 as an architecture and reboot into the newly migrated system. We verify that the system considers itself amd64 with no foreign architectures.

$ sudo dpkg --remove-architecture i386
$ dpkg --print-architecture
amd64
$ 
$ dpkg --print-foreign-architectures
$ dpkg --list   grep i386   wc -l
0
$ dpkg --list   grep amd64   wc -l
181
$ sudo shutdown -r now
Broadcast message from root@wheezyarch (pts/0) (Wed Jun 12 16:09:24 2013):
The system is going down for reboot NOW!
$ Connection to wheezyarch.zugschlus.de closed by remote host.
Connection to wheezyarch.zugschlus.de closed.
$ ssh wheezyarch.zugschlus.de
Linux wheezyarch 3.9.4-zgsrv20080 #2 SMP PREEMPT Wed Jun 5 13:12:04 UTC 2013 x86_64
$ dpkg --print-architecture
amd64
$

We now check whether we have lost any packages in this process:

$ sudo dpkg --get-selections   grep install   awk  print $1    sed  s/:.*//;s/$/:amd64
install/;  > get-selections.post
$ wc -l get-selections.*
  234 get-selections.post
  226 get-selections.pre
$ diff --unified=0 get-selections.pre get-selections.post 
--- get-selections.pre  2013-06-12 19:47:40.278176000 +0200
+++ get-selections.post 2013-06-12 20:28:51.389874000 +0200
@@ -22,0 +23 @@
+cpio:amd64 install
@@ -58,0 +60 @@
+initramfs-tools:amd64 install
@@ -68,0 +71,3 @@
+kernel-image-zgserver:amd64 install
+kernel-image-zgsrv20080:amd64 install
+klibc-utils:amd64 install
@@ -108,0 +114 @@
+libklibc:amd64 install
@@ -163,0 +170,2 @@
+linux-firmware-image:amd64 install
+linux-image-3.9.4-zgsrv20080:amd64 install

So we have not actually lost things, but we have gained the pure amd64 kernel and the packages that are needed to build a proper initrd. These were missing from the initial install of the i386 test VM. The downside of the process is that we have lost most of the automatically installed markers in aptitude which make sure to remove a library once nothing depends on it any more. If you make a point in having those markers correctly set, as I do, this is tedious work to set it on every package in the aptitude curses interface, making aptitude suggest removing the entire system, and then again remove it from the packages you actually intend to keep. This should not result in anything being removed, otherwise you have goofed previously. All Done! I am now off perfecting my upgrade process so that the i386 lenny and squeeze machines can first be moved to wheezy and then to amd64.

It was pointed out to me that some requests on my blog returned RSS rather than HTML content. This was the result of an upgrade from Debian 6.0 "squeeze" to 7.0 "wheezy", which changed something so that content negotiation for PHP files was disabled. I'm not sure what exactly changed; it's either the default in apache upstream, or something in a file that I hadn't modified and thus was replaced with the upgrade. At any rate, the fact was that I had configured mod_mime to have a line like

AddType application/rss+xml;qs=0.9 .rss

Which was sufficient, in squeeze, to tell apache not to prefer RSS files over their PHP variants. I found that in wheezy, the PHP mime type was not listed anywhere, which, combined with mod_negotiation's default setting of MultiviewsMatch NegotiatedOnly meant that the .php files weren't even being considered. The short-term solution was thus to add a line for PHP files:

AddType application/x-httpd-php .php

An alternate solution would be to switch to MultiviewsMatch Any, but I'd recommend against that, for reasons explained in the documentation. Of course, the long-term solution is to finally do that migration from blosxom-with-php-export to ikiwiki that I've been off and on contemplating ever since Joey announced he'd started working on ikiwiki. But, well, that's not for today.

There is a certain cross-over between the Debian Edu / Skolelinux project and the Edubuntu project, and for example the LTSP packages in Debian are a joint effort between the projects. One person with a foot in both camps is Jonathan Carter, which I am now happy to present to you. Who are you, and how do you spend your days? I'm a South-African free software geek who lives in Cape Town. My days vary quite a bit since I'm involved in too many things. As I'm getting older I'm learning how to focus a bit more :) I'm also an Edubuntu contributor and I love when there are opportunities for the Edubuntu and Debian Edu projects to benefit from each other. How did you get in contact with the Skolelinux / Debian Edu project? I've been somewhat familiar with the project before, but I think my first direct exposure to the project was when I met Petter [Reinholdtsen] and Knut [Yrvin] at the Edubuntu summit in 2005 in London. They provided great feedback that helped the bootstrapping of Edubuntu. Back then Edubuntu (and even Ubuntu) was still very new and it was great getting input from people who have been around longer. I was also still very excitable and said yes to everything and to this day I have a big todo list backlog that I'm catching up with. I think over the years the relationship between Edubuntu and Debian-Edu has been gradually improving, although I think there's a lot that we could still improve on in terms of working together on packages. I'm sure we'll get there one day. What do you see as the advantages of Skolelinux / Debian Edu? Debian itself already has so many advantages. I could go on about it for pages, but in essence I love that it's a very honest project that puts its users first with no hidden agendas and also produces very high quality work. I think the advantage of Debian Edu is that it makes many common set-up tasks simpler so that administrators can get up and running with a lot less effort and frustration. At the same time I think it helps to standardise installations in schools so that it's easier for community members and commercial suppliers to support. What do you see as the disadvantages of Skolelinux / Debian Edu? I had to re-type this one a few times because I'm trying to separate "disadvantages" from "areas that need improvement" (which is what I originally rambled on about) The biggest disadvantage I can think of is lack of manpower. The project could do so much more if there were more good contributors. I think some of the problems are external too. Free software and free content in education is a no-brainer but it takes some time to catch on. When you've been working with the same proprietary eco-system for years and have gotten used to it, it can be hard to adjust to some concepts in the free software world. It would be nice if there were more Debian Edu consultants across the world. I'd love to be one myself but I'm already so over-committed that it's just not possible currently. I think the best short-term solution to that large-scale problem is for schools to be pro-active and share their experiences and grow their skills in-house. I'm often saddened to see how much money educational institutions spend on 3rd party solutions that they don't have access to after the service has ended and they could've gotten so much more value otherwise by being more self-sustainable and autonomous. Which free software do you use daily? My main laptop dual-boots between Debian and Windows 7. I was Windows free for years but started dual-booting again last year for some games which help me focus and relax (Starcraft II in particular). Gaming support on Linux is improving in leaps and bounds so I suppose I'll soon be able to regain that disk space :) Besides that I rely on Icedove, Chromium, Terminator, Byobu, irssi, git, Tomboy, KVM, VLC and LibreOffice. Recently I've been torn on which desktop environment I like and I'm taking some refuge in Xfce while I figure that out. I like tools that keep things simple. I enjoy Python and shell scripting. I went to an Arduino workshop recently and it was awesome seeing how easy and simple the IDE software was to get up and running in Debian compared to the users running Windows and OS X. I also use mc which some people frown upon slightly. I got used to using Norton Commander in the early 90's and it stuck (I think the people who sneer at it is just jealous that they don't know how to use it :p) Which strategy do you believe is the right one to use to get schools to use free software? I think trying to force it is unproductive. I also think that in many cases it's appropriate for schools to use non-free systems and I don't think that there's any particular moral or ethical problem with that. I do think though that free software can already solve so so many problems in educational institutions and it's just a shame not taking advantage of that. I also think that some curricula need serious review. For example, some areas of the world rely heavily on very specific versions of MS Office, teaching students to parrot menu items instead of learning the general concepts. I think that's very unproductive because firstly, MS Office's interface changes drastically every few years and on top of that it also locks in a generation to a product that might not be the best solution for them. To answer your question, I believe that the right strategy is to educate and inform, giving someone the information they require to make a decision that would work for them.

So I'd previously talked about migrating machines. From having one virtual machine running "mail" + "web" + "stuff" I've now got three hosts:

ssh.steve.org.uk

This is supposed to be used solely for shell access, email reading, IRC. Sadly it still hosts one website, the web interface to my Mercurial repositories. This can't be moved without moving the repositories which is a step too far. Although I don't particularly want people browsing my code/changes I do want them to be able to clone them. If I could get anonymous-SSH checkouts working, sanely, then I'd be happy, but I don't see how to do that.

skx-web

This hosts all my websites except for two. The two that are excluded are my mercurial repositories, which still lives on ssh.steve.org.uk, and my blogspam service.

blogspam

This runs my blogspam.net service. I wish I could retired this, since it uses cruftly XML::RPC. I'd rather see a RESTful application sending/receiving JSON. Sadly I can't kill it without annoying a lot of people. So it must remain.

I chose to add the blogspam guest, because that service does really take over an IP, and it just seemed simplest to move it to one machine. As a quick hack both http://repository.steve.org.uk & http://blogspam.net/ run under Apache. Although the other websites run under their own UID with thttpd + my proxy. Now time to change the subject entirely. I've recently joined gym. Which isn't as horrible as I thought it might be, though as a matter of policy I refuse to go on any of those fancy running/jogging machines. The first three weeks I just alternated between the cycling machines and the rowing machines. Initially ten minutes on each, then twenty, then thirty. Now I'm being all brave and adventurous, using new machines and pieces of equipment. Writing this I've got a dull ache in both my arms, after doing seated-dips with 100Lbs. So I guess I'm starting to make progress. No specific goals in mind, but I've been paying slightly more attention to my diet over the past month and I think if I'm a "little fitter" and have "slightly nicer arms" then I'll be happy enough. I've no desire to go all anal and count calories, or give up chocolate and beer. So it is almost hard to explain why I'm going, but .. it is fun, and watching the numbers change is fun too. I'll probably post more about this in the future.