Since the launch of Identi.ca a few weeks ago, I've had a very busy time. Not much sleep, but lots of fulfilling and exciting work. It's invigorating to work on something that is popular and that you believe in. And I'm glad that the Franklin Street Statement so succinctly encapsulates those beliefs. As some people may have read in my previous blog post about the motivations behind creating Identi.ca (see Journal/14 Messidor CCXVI), I was part of a group convened at the FSF to discuss the impact of the growth of software as a service on user autonomy. It was a very loose organization of hackers, activists, and scholars who come from different backgrounds but all share an interest in user rights online. As computing moves into "the cloud" (see cloud computing), what power does the user retain to control their own computing experience? As much of our social lives -- romance, family, work, friends -- becomes Web-enhanced, what can we do to assert our right to manage that data and its use? How can software developers and service providers gauge their own proper ethical behaviour, and how can users of services judge what is and is not acceptable to use? We didn't come up with any easy answers, but we've summarized our thinking in a new document: the Franklin Street Statement on Freedom and Network Services. In essence, we've tried to point a direction towards what software developers, service providers, and software users should think hard about when thinking about network services. Our group will continue to explore these issues on our new group blog, http://autonomo.us/ . We're going to concentrate on the effects of software services on user autonomy -- people's ability to make their own informed choices about their data and creative works and the software that processes them. It is a realm that as a society -- a cluster of societies -- we're only beginning to understand, and I think that there is still a lot of exploration to do. Autonomo.us includes a wiki where we'll be exploring some of these ideas, and the blog will feature guest submissions about the subject. We're a loose and unofficial group with some smiling benevolence but no sanction from the FSF or any related organization, so we're really going to dig into some of the gray areas of this issue without worrying about making official statements for any one organization. I'm looking forward to the coming months and I hope this issue captures the imagination of the Web's Open Source and Open Content communities. P.S. You can see the FSF press release about the statement and the launch of autonomo.us. tags: autonomy franklinstreet softwareasaservice

Open Service Definition On a related note, one of the first organizations to approach the issue of Open Services has been the Open Knowledge Foundation. Today they've launched the 1.0 version of the Open Software Service Definition (OSSD). I think the OSSD 1.0 is a great step. It's a bar against which we can start measuring Open Software Services. For example, I think that Identi.ca meets the requirements of the OSSD. Other sites, like Wikipedia, are also clearly compliant. Some services that I really like, such as OpenStreetMap and geonames.org, seem to be compliant. But are they? It's good to start this investigation. I think other kinds of services are on their way there. The announcement by Reddit that their code will now be Open Source is a great step for user autonomy in the social news arena. Now, Reddit needs to consider what an Open Content/Open Data policy would mean for their service... or see others implement it on other sites. I look forward to a rich ecology of open software services growing, now that we have a name for it and a clear community of people interested in the topic. tags: autonomy ossd openknowledge

Looking through mail logs. After 7 days or so of spamassassin churning, I've managed to process about 20 days of e-mail and caught up to email since 5 days ago. Looking at some bugs to see if something is urgent.

I've just uploaded a new package for the SPIP content management webapp. SPIP is a very powerfull CMS made by a team of french coders. It is widely used in the french-speaking part of internet, used in thousands of sites, ranging from personal home page to professional publication websites. SPIP is somehow not well known in the eglish-speaking world, probably because most of the things happen in French... However, it's fully translated and documented in English, as well as many other (...)

I have just uploaded new SE Linux policy packages for Debian/Unstable which will go into Lenny (provided that the FTP masters approve the new packages in time). The big change is that there are no longer separate packages for strict and targeted policies. There is now a package named selinux-policy-default which has the features of both strict and targeted. When you install it you get the features of targeted. If you want the strict features then you need to run the following commands as root: semanage login -m -s user_u __default__
semanage login -m -s root root Then you can logout and login and you get the main benefit of the strict policy (users being constrained). IE you can convert from targeted to strict without a reboot! The above only changes the access for user login sessions (and cron jobs). To fully convert to the strict policy you need to remove the unconfined module with the command “semodule -r unconfined“, currently that results in a system that doesn’t boot - I’m working on this and will have it fixed before Lenny. Also it’s possible to have some users unconfined and some restricted in the way that strict policy always did. When running in the full strict configuration you need to run the command “newrole -r sysadm_r” immediately after logging in as root. When you login you default to staff_r which doesn’t give you the access needed to perform routine sys-admin tasks. Due to the change in the function of the policy packages (in terms of not having a strict package) it made sense to revise the naming (Fedora 9 has a package named selinux-policy-targeted which also provides the strict configuration - I don’t want to do that and don’t have as much legacy as Fedora). This is why I decided to not have package names that include the word “policy” twice. Of course all policy packages get new names, but the ones that matter needed new names anyway. Another new feature is the package selinux-policy-mls, as the name suggests this implements Multi Level Security [1]. I don’t expect that the MLS policy will boot in enforcing mode in a regular configuration at this time (you could probably hack it to boot in permissive mode and switch to enforcing mode just before it starts networking). I uploaded it in this state so that people can start testing it (there is a lot of testing that you can do in permissive mode) and so that it can get added to the package list in time for Lenny. I expect that I’ll have it booting shortly (it should not be much more difficult than getting the strict configuration booting). In terms of the use of MLS, I don’t expect that anyone will want to pay the money needed for LSPP [2] certification. NB The wikipedia page about LSPP really needs some work. I believe that the main benefit for having MLS in Debian is for the use of students. I periodically get requests from students for advice on how to get a job related to military computer security. Probably the best advice I can offer is to visit the career section of an agency from your government that works on computer security issues, for US readers the NSA careers page is here [3]. The second best advice I can offer is to work on MLS support in your favourite free OS. Not only will you learn about technology that is used in military systems but you will also learn a lot about how your OS works as MLS breaks things. ;) Finally I’d like to thank Manoj for all his work. For a while I didn’t have time to do much work on SE Linux and he did a lot of good work. Recently he seems to have been busy on other things and I’ve had a little more time so I’m taking over some of it.

• [1] http://en.wikipedia.org/wiki/Multilevel_security


• [2] http://en.wikipedia.org/wiki/Labeled_Security_Protection_Profile


• [3] http://www.nsa.gov/careers/

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So first the bad news is that I'm not coming to DebConf this year. There are a few reasons for this. It's fairly far and expensive. I thought the lineup of talks was pretty similar to the last two years. And perhaps most fundamentally, I don't want to go somewhere cold (well, cool) in the summertime. I think this may be a Canadian thing, but I love summer time and I don't want to squander any of my warm days. So have a good time folks, I'll miss you and I'm certainly going to make the effort to be there next year. And lets hope DebConf 10 is in Montr al :)

I will however be heading to OLS for the first time. Which is ironic because I used to live 2 hours from Ottawa and never went. Now I live several more hours away and now I've decided to go. Irony is fun.

I'm also thinking of attending HOPE here in New York. I'm not really sure what to expect. The talks seem really eclectic, which is cool, but makes it hard to figure out what to go to. Suggestions welcome!

Lucy left for England yesterday (OK, now it’s two days ago — last Friday). That means that I have unusual amount of free time at my hands, and yet even more things that could be done with it. But I suppose it’s time to update this little blog. It’s probably pointless to enumerate what happened, or what changed. Everything is fine and smooth over here — the wrinkles get worked out over time (with Lucy, without Lucy). Hobbies still take time and I still haven’t given up. My latest determination is to get myself a bassoon for next Christmas. (Now, that will be a year since we got Lucy a Marigaux 901, used, in great condition for a great price, lo and behold, on Austrian ebay. World is so weird sometimes…) And in the land of [LVM], I have finally started the process to merge code to improve LVM’s behaviour in presence of failed storage hardware (physical volumes gone missing). In the land of Adept, well… first things first. FOSSCamp I have visited Prague for the latest Ubuntu- (well, Canonical-) organised event, the FOSSCamp. I have met Johnatan (KUbuntu), Seli (KWin), Lidya (Amarok), Robert (Konsole), Jos (Strigi) and Inge (KOffice). See also Johnatan’s Blog (including a real blurry picture). So back to Adept — I had some hacking time over there in Prague, and I have almost brought Installer and Updater back to life for Adept 3. I unfortunately didn’t have as much time for it since then — but my current free time situation does open up some possibilities. First and foremost, I should really make a text interface to the underlying libraries for myself, maybe with fancy colourful UI, hopefully one that is comfortably close enough to apt-get and still offers advantages. Hmmmm… Intermezzo 1 Now zoom out and zoom in somewhere else, enough of coding matters. Our research group at the University had a (tool) paper accepted for ATVA 2008, meaning that I am not unlikely to visit Seoul, South Korea in October. Another piece of distant world to visit. FOSDEM Now, that reminds me… Since the last time, I have also been in Belgium — to visit FOSDEM — meeting Alasdair (of LVM) and Bart and Pino of Krita and Okular, respectively… although unfortunately, I didn’t spend nearly enough time with Pino… At least we have spend a day walking around Ghent with Bart (and Lucy, who visited Belgium with me, also having friends of her own there). Moreover, I have spent a lot of mostly productive time with Alasdair, discussing LVM2. And Belgium is nice and pretty, although I didn’t really get around to taste any beer. Maybe next time. And Antwerps were nice, too. Photos? Someday. LinuxTag And after that, I have visited Berlin again, for LinuxTag as usual — plus the accompanying LVM discussions, with Milan, Kabi and Mikul (Blek) of the Czech part of the team, and Heinz, John and of course Alasdair for the rest of the world… Also as usual, we walked around, had dinners, discussed non-work stuff, etc… a good event all in all. At LinuxTag, I have briefly seen Lidya again, as well as Ossi (whom I nearly didn’t recognise…) and Aaron who (for a change) didn’t recognise me (but to be fair, I didn’t quite stop by to chat and he’s been busy…) and Sebas, cordial as ever (and always a pleasure to meet)… reminds me of Paris two years ago, too. Intermezzo 2 Less than a month ago, I have finished my first semester of master’s study — two or three more to go (I have completed bachelor’s the semester before). Yes, I am a bachelor of computer science, or something like that, anyway, now. Or so I hope. I did not attend the whatever ceremony and I don’t really have the diploma (or maybe I do, but gods know where it is…). A short note on Debian with best intentions I am now sponsoring Trent Buck’s ?darcs packages, contributing a little on the go (making me wish that alpha buildd would make a little more progress…). With Enrico, we have uploaded new versions of wibble and libept, both of which I think make both of us fairly happy. (Although we again managed to hit a way strange compiler issue (only manifested on arm… what have I done that the gods punish me so?), as documented in Debian bug 487406…) I have packaged dzen2 and taken over haskell-mode (I am losing track of my own packages again — I really need to set up reliable watch files so I don’t miss out too many releases… apparently neither has new upstream versions, so I can sleep peacefully for a little longer). Intermezzo 3 I am not going to DebConf nor Akademy this year. That makes me a little sad, but it’s all my own fault (and laziness). Next time folks, next time. I haven’t seen K vin in aeons and he probably removed me from his memory by now… No matter, I’ll try a little harder next year, promise (oh, how many have I made to date?). Finale Nothing grandiose, just best wishes to everyone, I have to land in bed now it seems, as I am ever so sleepy. (Just So Stories, anyone?) There I go.

Frederico’s talk had some bits that reminded me of a “Topaz” desktop design that came up on desktop-devel-list back in ‘06. It wasn’t given much time of day back then though. Check it out. The concept of the computer as Personal Assistant appeared in a few forms this year. Concepts like it helping you organize your information and time and managing your attention. Its obvious there’s been a few threads of thought on this bubbling away for a while now and this year you could see ideas starting to crystallize. Very cool! Its obvious we’re going to need some good query capabilities over large RDF trees. To my simple mind this seems to basically involv unification over tuples, so prolog keeps popping into my head. Has anyone checked out SeRQL?

In times where screen resolutions of 1600x… and above are becoming more and more common, I wonder if the maximize window button which enlarges a window to take all the available space on the desktop is still as useful as it used to be. I noticed that some (if not all, I’m not a Mac user) applications on Mac only maximize their windows depending on the content of the window. For example if you maximize the window of your word processor, the window becomes only as wide as necessary to make the whole page visible. This doesn’t just look better on very large monitors, it is also more usable than a simple maximize since it doesn’t unnecessarily hide other windows. Is there a window manager for Linux which does something similar, or better: is something like this possible with KDE? I know that QT widgets have a “preferred size” — shouldn’t it be possible to have a maximize to preferred size button? It’s surely not useful for every application, but may applications only need a quite small main window and look very ugly when maximized.

So recently there have been a few posts by people discussing the idea of distributed bug reporting systems. This is topical, becuse I've been working on something vaguely related - a support system. Why is a support system, or ticketing system, related to a bug tracker? To answer that you must first clarify what you mean by a support system (or a bug tracker for that matter). There are two distinct types of support systems:

"Full"

This is a system which does "everything". Each submitted support, or bug, request has an associated status, severity, priority and work log. It might be assigned to multiple people through its lifetime, and it might be moved around various internal queues. Example: Request Tracker.

"Minimal"

A reported ticket is an email submission. A "ticket" from start to finish is nothing more than a collection of mails upon a particular topic - there is no assigned "owner", no "priority", no object-specific attributes at all.

I've neither the time, patience, or desire to create any system like the first one. But I've become increasingly dissatisfied with my current support system, roundup, for various reasons. So I need something new. Previously I ruled out several support systems and most of my objections still stand, although I admit I've not really looked again. I will certainly do so shortly. So what have I done? Well I figure I care very little about queues, priorities, reports, and all that stuff. (On the basis that priority is mostly in the ticket itself, and that I'm the sole recipient of the submissions. Previously I had a partner to share them, but these days just me.) I want something that is basically e-mail centric. That reduces the functionality of my support system to two distinct parts:

Ticket Submission

An email to sumbit@example.com should result in three actions:

• A message being sent back to the submitter. "Hey got your ticket. We'll fix it. Love you long time.". (Set the reply-to address appropriately!)
• A message to the site admin(s) saying "Hey, you've got a new ticket submission. Deal."
• A new ticket being created/stored somewhere.

(There are additional nice things to have - such as SMS alerts outside 10:00-17:00, etc, but those are trivial bolt-ons.)

Ticket Updates

When a mail comes in to "ticket-XXXX@example.org" - which was setup in the submission process, or when a mail arrives with subject "[issueXXXX]" we need to append the correspondance to the existing ticket. If that ticket doesn't exist we report an error. If the ticket is closed we re-open it.

So, what do we have? A script that is conceptually simple, and can be invoked via a pipe transport of Exim4. A script that just reads the submitted email from STDIN and only has to decide a couple of things based pretty much on the contents of the "To:" and "Subject:" headers. Simple, no? OK it was actually amazingly simple once broken down. The amazing part is that it all works. I figured that I'd manage new tickets by writing them to mbox files - simple to do. Simple to understand. So the process goes:

• New email arrives to "submit@example.org"
• /home/steve/tickets/1 is created with the received message written to it.
• I get a mail to steve@steve.example.org.uk saying "new ticket!!!".
• I reply to the ticket by opening /home/steve/tickets/1 in mutt - where my muttrc ensures that when I reply the from address is the ticket address, and there is an automatic CC.
• The cycle turns, and more discussion happens until we're all happy the ticket is "done"..
• A mail to ticket-xxxx-done@example.org" closes the ticket by moving it from ~/tickets/ to ~/tickets/archived/.

There are a couple of helper scripts:

• ticket-close - close a ticket manually.
• ticket-list - show all open tickets
• ticket-view - open a ticket in mutt

But basically one script and mutt does it all. So far it's been tested and it is rockin'! (Look at me, hangin' with the cool kids!) Obviously it is pretty Steve-specific, and there is only a toy CGI process for viewing history online, but I'm actually feeling pretty good about it. Once I've closed all my existing tickets I will probably migrate over to it. At least this handles (read: ignores) MIME - which makes it a clear winner of roundup, which just eats, bounces, or corrupts submitted multipart messages. ObQuote: Flash Gordon

Yay! I just handed in my Diploma thesis in Computer Science (approx. Masters degree). It will still be some weeks until it has been graded, the dean has signed the diploma etc., but I'm pretty much done.The topic of my thesis is

Statistical Approaches for Robustifying Correlation Clustering Algorithms

so my field of research is Data Mining, in particular Data Clustering and Outlier Detection. My particular contribution is to improve the accuracy of PCA results in the presence of noise.Some ideas of the thesis are also just being published at the 20th International Conference on Scientific and Statistical Database Management (SSDBM) July 9-11, 2008, Hong Kong, China and the associated proceedings (Springer LNCS volume 5069):

Hans-Peter Kriegel, Peer Kröger, Erich Schubert and Arthur Zimek. A General Framework for Increasing the Robustness of PCA-based Correlation Clustering Algorithms

Other related publications will follow (an outlier detection method using parts of my thesis will be submitted to a journal soon, too). And in case the first name on that list rings a bell: he did some major contributions to multi-dimensional data structures such as the R*-Tree, X-Tree and Buddy Tree, and has since been very active in data mining.I'll be giving a short talk at the graduate seminar next week, and I'll probably publish the slides on my web page. But they will only be a short excerpt of my work due to time limitations of the talk.So basically, I'm jobless now! :-)I still have plenty of related ideas to continue research, and my advisor asked me if I'd like to continue with a PhD degree (so you can assume the grade of the thesis won't be too bad). However, the university is always short on open positions, and I don't know if I'll be able to get one (a research proposal is pending). Therefore, I'm looking for a position that allows be to pursue data mining and/or clustering research. Part time jobs are fine if they are well enough paid, although it of course would be best if the job would just include related research. If the job is located outside of Munich, a contact to a local university with a strong data mining research group is needed. (In Munich I obviously already have contacts to a strong research group.)As you might figure from me posting on Planet Debian, Planet GNOME and similar, I'm fairly experienced in OpenSource and Linux (something like 19 years of programming experience, 13 years of Linux experience). So I'm not just a fresh graduate, but a doer when it comes to coding. (Which is partially why I'd prefer a job outside of the university!)Anyone with interesting job offers (Google Munich anyone? I've been trying to get a back channel contact with you for weeks), please just drop me an email at erich AT debian DOT org.P.S. No, that doesn't mean I'm only looking for jobs in the data mining field. It would just be more convenient.

New status update! Here’s what Aptitude looks like: (more screenshots after the break) I’ve been exploring how the APT libraries work and how to interact with the aptitude back-end and here’s what it can do now:

• Update package lists
• Display package lists
• Basic package search
• Mark packages for install/remove/purge/keep/hold
• Display package actions for execution
• Display conflicts
• Display and navigate between package conflict solutions
• Apply them
• Execute package actions (ie. actually install stuff)

What’s missing:

• A real user interface
• Being reliable…
• Packages dependencies, pre-dependencies, etc.
• Hyperlinks between packages
• Advanced package search
• Tags support (tag clouds ?)
• Linking with interesting data sources like popcon
• A lot of interesting things

Basic functions of a package manager are already covered. We’re still at the APT API exploration phase although we’re almost done with it. I will soon start working on the final user interface and the real code design. The current code is about 2000 lines of hastily hacked together C++ and XML. I’ll have to restart the coding with a more elaborate Object design. Something that will be easier to work with in the future. The code is on http://dev.graffit.net/aptitude/trac. You can try to compile it and play with it. On the other hand I’m going to scrape most of the code soon for the restart so if you’re bored.. A walkthrough and more screenshots after the break. Here’s a walkthrough of what you can do right now:

Like many people, I participated in the Google Android contest this spring, and like most of them, I didn't win, but I did enjoy working with the platform, and am very excited about the idea of an open source mobile platform that's relatively powerful. From the outset, due to the lack of actual source code for a lot of the system, there have been "doubters" about what Google is really up to. I'm not one of them, and am largely ok with their reasons for holding back: I buy their reasoning that the long term benefits of a strong, properly QA'ed launch probably outweigh the possibility of failure that might come from the press and the public at large that doesn't care much about software freedom seeing phones come out with half-baked, early implementations. I think most of us working with Android were ok with that strategy, and the ones who weren't self-selected out of the platform, most likely. However, lately Google has made something of a mess of their communications regarding Android. The problem stems from the fact that they gave an updated version of the SDK only to the winners of the competition, which for a lot of people felt like a bit of a slap in the face: they helped popularize the platform by participating in the contest and writing applications for it, and in return got excluded from the upgrade path. Personally, it's not really any skin off my nose, as I'm sanguine about the Hecl port proceeding apace when the new SDK is public, but I can see that if you were, say, a company porting your app to the platform and now are left behind the competition winners, you might be a bit irritated. The biggest mistake they've made though, is a big lack of communication regarding this business. As I said, I don't really have that much skin in the game, and if they explained in a convincing way why they needed to do things that way, they would go a long ways to allaying the frustrations felt by many. I'm not much of a believer in conspiracy theories and plots, especially where companies are concerned. Inept bumbling is a far more likely explanation in most cases, including this one. What is odd, though, is that Google has a lot of people who "get it". I met Dan Morrill at the Munich Android event, and he definitely gets it. He writes about his frustrations as a developer advocate and all the crazy things people say. Well, one way to reduce the number of batty internet theories (eliminating them is clearly impossible due to the alien mind control rays) is to consistently communicate quality information about what's really going on, something that has been lacking with regards to the SDK question. Here's another Google employee who understands this need to communicate, and apparently does so despite being worried about being "slapped for talking publicy about all this": http://groups.google.com/group/android-developers/msg/244edfad99870c63

But the root of the problem is certainly not licensing but that there hasn't been a new public SDK release since M5, while at the same time a small group of people received updated versions privately. I really don't know precisely why this happened; but I'm sure it has more to do with logistics and reducing the burden of support while we shift priorities (to shipping real devices) rather than politics or any will of our part to "hurt the community" (come one guys, we are not that stupid... !) While others in the team may disagree, I think it was very very unfortunate; some of us are trying to prepare a new SDK release, but it's a lot harder than I can comment on here, so don't hold your breath because it might not happen that soon.

This explains things in part, but still leaves us in the dark, and leaves me with the feeling that someone in power, somewhere at Google, despite his or her clued in colleagues, really doesn't get it with regards to open source. I'm still unconcerned about the Android source code: I think we'll see it, but to be a true open source project, Android will need an open community as well, not one where decisions are taken exclusively at Google, and not even communicated to the development community at large. All in all, this mistake is more molehill than mountain, but however you look at it, in terms of open source, it is a step backwards.

Someone asked on a mailing list about the issues related to whether to use a label, UUID, or device name for /etc/fstab. The first thing to consider is where the names come from. The UUID is assigned automatically by mkfs or mkswap, so you have to discover it after the filesystem or swap space has been made (or note it during the mkfs/mkswap process). For the ext2/3 filesystems the command “tune2fs -l DEVICE” will display the UUID and label (strangely mke2fs uses the term “label” while the output of tune2fs uses the term “volume name“). For a swap space I don’t know of any tool that can extract the UUID and name. On Debian (Etch and Unstable) the file command does not display the UUID for swap spaces or ext2/3 filesystems and does not display the label for ext2/3 filesystems. After I complete this blog post I will file a bug report. If you are using a version of Debian earlier than Lenny (or a version of Unstable with this bug fixed) then you will be able to easily determine the label and UUID of a filesystem or swap space. Other than that the inconvenience of determining the UUID and label will be a reason for not using them in /etc/fstab (keep in mind that sys-admin work sometimes needs to be done at 3AM). One problem with mounting by UUID or label is that it doesn’t work well with snapshots and block device backups. If you have a live filesystem on /dev/sdc and an image from a backup on /dev/sdd then there is a lot of potential for excitement when mounting by UUID or label. Snapshots can be made by a volume manager (such as LVM), a SAN, or an iSCSI server. Another problem is that if a file-based backup is made (IE tar or cpio) then you lose the UUID and label. tune2fs allows setting the UUID, but that seems like a potential recipe for disaster. So this means that if mounting by UUID then you would potentially need to change /etc/fstab after doing a full filesystem restore from a file-based backup, this is not impossible but might not be what you desire. Setting the label is not difficult, but it may be inconvenient. When using old-style IDE disks the device names were of the form /dev/hda for the first disk on the first controller (cable) and /dev/hdd for the second disk on the second controller. This was quite unambiguous, adding an extra disk was never going to change the naming. With SCSI disks the naming issue has always been more complex, and which device gets the name /dev/sda was determined by the order in which the SCSI HAs were discovered. So if a SCSI HA which had no disks attached suddenly had a disk installed then the naming of all the other disks would change on the next boot! To make things more exciting Fedora 9 is using the same naming scheme for IDE devices as for SCSI devices, I expect that other distributions will follow soon and then even with IDE disks permanent names will not be available. In this situation the use of UUIDs or LABELS is required for the use of partitions. However a common trend is towards using LVM for all storage, in this case LVM manages labels and UUIDs internally (with some excitement if you do a block device backup of an LVM PV). So LV names such as /dev/vg0/root then become persistent and there is no need for mounting via UUID or label. The most difficult problem then becomes the situation where a FC SAN has the ability to create snapshots and make them visible to the same machine. UUID or label based mounting won’t work unless you can change them when creating the snapshot (which is not impossible but is rather difficult when you use a Windows GUI to create snapshots on a FC SAN for use by Linux systems). I have had some interesting challenges with this in the past when using a FC based SAN with Linux blade servers, and I never devised a good solution. When using iSCSI I expect that it would be possible to force an association between SCSI disk naming and names on the server, but I’ve never had time to test it out. Update: I have submitted Debian bug #489865 with a suggested change to the magic database. Below are /etc/magic entries for displaying the UUID and label on swap spaces and ext2/3 filesystems:
The following magic entry will display the UUID of a swap space as well as displaying the label in the same manner as the mkswap program:
# according to man page of mkswap (8) March 1999
# volume label and UUID Russell Coker
# http://etbe.coker.com.au/2008/07/08/label-vs-uuid-vs-device/
4086 string SWAPSPACE2 Linux/i386 swap file (new style),
>0×400 long x version %d (4K pages),
>0×404 long x size %d pages,
>1052 string \0 no label,
>1052 string >\0 LABEL=%s,
>0×40c belong x UUID=%x
>0×410 beshort x \b-%x
>0×412 beshort x \b-%x
>0×414 beshort x \b-%x
>0×416 belong x \b-%x
>0×41a beshort x \b%x The following magic entry will display the UUID and label (AKA volume name) of an ext2/3/4 filesystem:
# ext2/ext3 filesystems - Andreas Dilger <adilger@dilger.ca>
# ext4 filesystem - Eric Sandeen <sandeen@sandeen.net>
# volume label and UUID Russell Coker
# http://etbe.coker.com.au/2008/07/08/label-vs-uuid-vs-device/
0×438 leshort 0xEF53 Linux
>0×44c lelong x rev %d
>0×43e leshort x \b.%d
# No journal? ext2
>0×45c lelong ^0×0000004 ext2 filesystem data
>>0×43a leshort ^0×0000001 (mounted or unclean)
# Has a journal? ext3 or ext4
>0×45c lelong &0×0000004
# and small INCOMPAT?
>>0×460 lelong <0×0000040
# and small RO_COMPAT?
>>>0×464 lelong <0×0000008 ext3 filesystem data
# else large RO_COMPAT?
>>>0×464 lelong >0×0000007 ext4 filesystem data
# else large INCOMPAT?
>>0×460 lelong >0×000003f ext4 filesystem data
>0×468 belong x \b, UUID=%x
>0×46c beshort x \b-%x
>0×46e beshort x \b-%x
>0×470 beshort x \b-%x
>0×472 belong x \b-%x
>0×476 beshort x \b%x
>0×478 string >0 \b, volume name "%s"
# General flags for any ext* fs
>0×460 lelong &0×0000004 (needs journal recovery)
>0×43a leshort &0×0000002 (errors)
# INCOMPAT flags
>0×460 lelong &0×0000001 (compressed)
#>0×460 lelong &0×0000002 (filetype)
#>0×460 lelong &0×0000010 (meta bg)
>0×460 lelong &0×0000040 (extents)
>0×460 lelong &0×0000080 (64bit)
#>0×460 lelong &0×0000100 (mmp)
#>0×460 lelong &0×0000200 (flex bg)
# RO_INCOMPAT flags
#>0×464 lelong &0×0000001 (sparse super)
>0×464 lelong &0×0000002 (large files)
>0×464 lelong &0×0000008 (huge files)
#>0×464 lelong &0×0000010 (gdt checksum)
#>0×464 lelong &0×0000020 (many subdirs)
#>0×463 lelong &0×0000040 (extra isize)

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(Advertisment) I have several packages to give away:

• endeavour - file and disk management suite
• avscan - GTK frontend for the Clam AntiVirus scanner (ClamAV)
• cryopid - Dumps a process into a self-executing file
• xar - eXtensible ARchiver
• minimalist - MINImalistic MAiling LISTs manager
• dtmfdial - DTMF Tone Dialer

If you are interested in taking any of these, please contact me. The first three have open RC-bugs that need some attention, they have been orphaned for some weeks, with no takers. endeavour and avscan are already on the way to RM, if you are interested in these, speak up now. Thanks :)

Mark is in town visiting after spending this last year at CMU. While here, he graciously organized a hiking trip to Sequoia National Park. We did around 20 miles over two days, 12 of which with full packs, and over 4000ft of climbing with full packs. The consequence of this work was that my old trusty camping backpack finally broke. The duct tape came loose, my sweat helped, and the left shoulder strap broke. This pack has lasted around 15 years, so it has done its job. Now is probably time for a new one.

My other bit of exercise was riding home from the tenderloin without a seat on my bike. Someone managed to get the seat, and post, off of my bike while it was locked up . Normally riding without a seat should be challenging, but not too bad. Unfortunatly, my bike is a fixie and I had clipless pedals and shoes with me today. I learned after the first block that I shouldn't clip in since it is very hard to clip out while pedalling and standing up. I also had a down hill section that was very scary. It turns out if you have your butt too far back on the bike that it becomes wobbly.

I learned a new word today, thunk. At first, given the context, I thought it meant text (as in program code) hunk, but the Hacker's Dictionary suggests it's actually more a term for a closure. For those not familiar with what a closure is, it's a "thunk" of encapsulated code created by the compiler which is dynamically generated and managed. Stealing the Wikipedia example: Nested functions are probably the closest thing to a closure you can get with C (I've talked about nested functions and trampolines before). However, because the stack disappears it's not nearly as useful, I think the term for these is lexical closures, because it's basically a way to share some stack and restrict name-spaces. Amusingly, the code using the term "thunk" was assembler, so my first search was for thunk gas (as in GNU Assembler). This of course lead to endless articles on the high price of gas — a non-renewable fossil fuel running out and capitalists realising inelastic demand can be used to line their pockets? Whoda' thunk it!

It's never too late. Today, I finally figured out that "TIA", which I see here and there in mails, is meaning "Thanks in advance". After about 20 years of electronic communication, it was about time. This is a great time for this as I recently figured out "IANAL" and "TTBOMK". Always learning, finally. Time for me to use these now. I think I'll use their French version (which nobody uses) to make this as cryptic as those acronyms were for me:

• MDA == TIA
• PAQJLS == TTBOMK (actually PAQJLS is more AFAIK, but heh)
• JNSPUA == IANAL

I have just observed demonstration units of the V-Smile system [1]. They have “educational games” aimed at ages 3-5, 4-7, and some similar ranges. The first thing I noticed was that children who were able to correctly play the games were a lot older than the designated ages. For example 10yo children were playing the Scooby-Doo addition game (supposedly teaching children to add single-digit numbers) and apparently finding the non-addition part of the game challenging (I tried it myself and found catching flying hamburgers while dodging birds to be challenging enough that it was difficult to find numbers). For children who were in the suggested age-range (and a suitable age for learning the basic lessons contained in the games) the only ones who actually managed to achieve the goals were the ones who were heavily directed by their father. So my observation is that the games will either be used by children who are too old for the basic lessons or be entirely directed by parents (I didn’t observe any mother giving the amount of assistance necessary for a 5yo to complete the games but assume that it happens sometimes). I doubt that there are many children who have the coordination needed for a platform game who have not yet learned to recognise printed letters (as supposedly taught in the Winnie the Pooh game). The Thomas the Tank Engine spelling game had a UI that was strange to say the least (using a joystick not to indicate which direction to go but instead to move a cursor between possible tracks) and I doubt that it does any good at teaching letter recognition. There was also a game that involved using a stylus for tracing the outline of a letter, as I had great difficulty in doing this (due to the poor interface and the low resolution of the touch-pad) it seems very unlikely that a young child who is just learning to write letters would gain anything from it. Strangely there was a game that involved using the touch-pad to indicate matching colors. Recognising matching colors is even easier than recognising letters and I don’t think that a child who can’t recognise the colors would be able to manage the touch-pad. The V-Smile system seems to primarily consist of a console designed for connection to a TV but also has hand-held units that take the same cartridges. The same company produces “laptops” which sell for $50 and have a very low resolution screen and only the most basic functionality (and presumably other useless games). Sometimes the old-fashioned methods are best. It seems that crayons are among the best tools for teaching letter recognition and writing. But if there is a desire to use a computer for teaching, then a regular PC or laptop should do. Letter recognition can be taught by reading the text menus needed to launch games. The variety of computer poker games can be used for recognising matching colors and numbers as can the Mahjong series of games. Counting can be taught through the patience games, and the GIMP can be used for teaching computer graphics and general control of the mouse and the GUI. NB I’m not advocating that all education be done on a computer, merely noting the fact that it can be done better with free software on an open platform than on the proprietary systems which are supposedly designed for education. Finally with a PC children can take it apart! I believe that an important part of learning comes from disassembling and re-building toys. While it’s obvious that a PC is not going to compare with a Lego set, I think it’s good for children (and adults) to know that a computer is not a magic box, it’s a machine that they can understand (to a limited extent) and which is comprised of a number of parts that they could also understand if they wanted to learn the details. This idea is advocated by Gever Tulley advocates such disassembly of household items in his TED talk “5 dangerous things you should let your kids do” [2]. Gever runs The Tinkering School [3] which teaches young children how to make and break things. Finally I just checked some auction sites and noticed that I can get reasonably new second-hand laptops for less than $300. A laptop for $250 running Linux should not be much more expensive than a proprietary laptop that starts at $50 once you include the price of all the extra games. For an older laptop (P3) the price is as low as $100 on an auction with an hour to go. Then of course for really cheap laptops you would buy from a company that is getting new machines for their staff. It’s not uncommon for companies to sell old laptops to employees for $50 each. At a recent LUG meeting I gave away a Thinkpad with a 233MHz Pentium-MMX CPU, 96M of RAM, and a 800*600 color display - by most objective criteria such a machine would be much more capable than one of those kids computers (either V-Smile or a competitor). Of course the OLPC [4] is the ideal solution to such problems. It’s a pity that they are not generally available. I have previously written about the planned design for future OLPC machines [5] which makes it a desirable machine for my own personal use.

• [1] http://www.vsmile.co.uk/


• [2] http://www.ted.com/index.php/talks/gever_tulley_on_5_dangerous_things_for_kids.html


• [3] http://www.tinkeringschool.com/blog/2005/about/


• [4] http://www.laptop.org/


• [5] http://etbe.coker.com.au/2008/05/21/the-new-olpc/

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