Look Mum, no bugs!
I recently encountered
a
bug in RhythmBox where, if you rename a directory, it thinks that all
the files in the old directory have disappeared and there's a whole bunch of
new files. You lose all the metadata - and for me that was hours of ratings
as I worked my way through my time-shiftings of the chillout stream of
Digitally Imported. Worse, if RhythmBox was
running during the rename, when you try to play one of those files that has
'gone missing' it will just say "output error"; when you restart it because
(naturally) you think it's borked its codecs or something, it then removes
all those previous entries (giving you no chance to fix the problem if you'd
just renamed the directory in error).
I decided to try to be good, so I found the GNOME bugzilla and tried to search for "directory", or "rhythmbox", or anything. Every time it would spend a lot of time waiting and then just finish with a blank page. Deciding that their Bugzilla was hosed, I went and got a Launchpad account and logged it there. Then, in a fit of "but I might have just got something wrong", I went back to the Bugzilla and tried to drill down instead of typing in a keyword.
Lo and behold, when I looked for bugs relating to "Rhythmbox", it turned up in the search bar as product:rhythmbox. Sure enough, if I typed in product:rhythmbox summary:directory then it came up with bugs that mentioned 'directory' in their summary line. If you don't get one of those keywords right, it just returns the blank screen as a mute way of saying "I don't know how to deal with your search terms".
So it would seem that the GNOME bugzilla has hit that classic problem: developer blindness. The developers all know how to use it, and therefore they don't believe anyone could possibly use it any differently. This extends to asserting that anyone using it wrong is "obviously" not worth listening to, and therefore the blank page serves as a neat way of excluding anyone who doesn't know the 'right' way to log a bug. And then they wonder why they get called iconoclastic, exclusive and annoying...
Sadly, the fix is easy. If you can't find any search terms you recognise,
at least warn the user. Better still, assume that all terms that aren't
tagged appropriately search the summary line. But maybe they're all waiting
for a patch or something...
posted at: 22:44 | path: /tech/web | permanent link to this entry
SELinux for SLUGs
Last Friday I gave two talks at the
Sydney Linux Users Group, at the
new Google offices. It was a pretty full-on day, as I'll explain in
another post, and I was keen to get to the meeting pretty quickly.
Fortunately the light rail in Sydney is pretty good, and finding ones way
from the Star City stop to the offices was pretty easy. I happened to
meet two people who were also going to the meeting, a lady escorting her
young nephew (if I recall correctly) - she came and asked me if I knew
where the linux group meeting was. I talked with them for a bit on the
tram, but I'm sorry to them if I was a little distracted - my thoughts
were on getting to the meeting, getting set up correctly and giving the
talk.
We arrived in the twilight zone between the day, when the lifts allow you to get to any floor without a pass, and the night, when the SLUG Google employees were shuttling people up to the fifth floor. So we climbed the ten flights of stairs - I was in the need of a bit of a stretch. I then picked up my name badge - they were using Anyvite, so they could print out named labels easily for those that had bothered to RSVP on the site so beforehand. I had a brief bit of hesitation when my laptop shut down because it thought it was out of power, a curious interaction between the failing battery and Fedora 11, but all came good. Then it was time to work out how to get connected to the projector.
This was the source of two startling discoveries. Firstly, Fedora 11's screen detection now works pretty much seamlessly - if you plug in a new screen and click the 'Detect Monitors' button, it just finds the new output on the VGA port and sets it up appropriately. Secondly, Open Office 3.0 has a 'presenter' mode that can take advantage of two screens and display your 'now and next' screen on your laptop screen while the projector just displays the current slide in all its streamlined beauty. This was one of those "Wow, It Just Works™" moments where you see how fast the pace of Linux development really is - I was all ready with arcane xrandr voodoo but this just worked perfectly.
Sadly, due to slight cabling problems my laptop was sitting on a server cabinet six meters away, but when I muttered to the nearest person that what I needed right now was a wireless presenter device, the same guy just pulled one from his bag and handed it to me. Whoever you are, you really made my day - thanks! Still, I would be deprived of the handy 'now and next' view and would occasionally have to look over my shoulder to make sure I was talking about the right thing. I'd practiced both talks beforehand, so I was able to move on fairly smoothly. If you're going to do presentations, you have to do this - reading off your slides or looking at the screen to see where you are is really embarrassing.
The two talks went well, though I didn't receive anywhere near the amount of heckling that the CLUG people gave me when I gave the same talks. The questions asked were generally quite insightful, and I had to think hard about my answers. I remembered to restate the question for the microphone, and got to give two T-shirts to people who asked good questions. So overall I was pretty pleased about how it went.
I was talking with Andrew Cowie after the talk, and he gave me some very useful advice for approaching talks in the future. After you've done your initial bit of research working out who you're talking to and what level your should pitch your talk at, you really just have to go for it. I'd been worried that it might be too technical for some and not technical for others - and it was, of course; the point is that that's not really my problem. There always will be that spectrum of knowledge in the people attending a talk at a volunteer organisation, and it's not the presenter's problem to try and cater for everyone. You simply have to do the best you can and reach the most people you can, and not worry about whether you've got everyone interested.
After the talk I got to spend a bit of time with Andrew talking about trades and professions, what makes good meetings and presentations, and many other things that are now lost in the blur that that Friday became. He's an excellent speaker and, like me, wants to see people doing the right thing - being moral and ethical in all their dealings. I also have a small envy of his globetrotting ways, and admire his ability to write Java as fast as think about it in Eclipse, so it was good to get a chance to talk to him for an extended time rather than the usual 'nod in the corridor' meetings we've had in the past.
Overall, a good night. I've put both the
SELinux
for Beginners and
SELinux
for Sysadmins talks up on SlideShare for people to read.
posted at: 23:59 | path: /tech | permanent link to this entry
What we owe Microsoft
Strangely, over the last month or two I've had a couple of people pose the
idea to me that the computer industry should be thankful to Microsoft for
producing Windows. One person stated that they keep us computer support
people in a job; the other said that Microsoft's development of Windows was
such an outstanding achievement that we should allow them to dictate how
we use our computers and how other software companies interface with
Windows. I've tried to debate rationally about these issues, given that
us people who use Free Open Source Software see them as akin to chocolate
on a fishing hook with a shotgun aimed at it - they're bait, and when you
take it you're going to end up hurt, but all the same... it's chocolate...
Let's start by saying that these arguments, to me, make no sense. Microsoft is a convicted criminal, an abusive monopoly that has lied, cheated, bankrupted, threatened, bullied and undermined its way to the top by killing off competition wherever it could. It's done all this not because they want to improve things for the users - although they've said this, that's why they're liars - but simply to maximise profits. It's obvious from everything they do that they see themselves as the 400-kilo alpha male silverback gorilla in the software industry, and that they should be able to do whatever they like with no justification. You can and they do, of course, attach justification to everything but it's merely the covering on a deeply abusive relationship. Saying that we owe them anything is like saying people deserve to be raped - it's literally unthinkable to me.
On the other hand, the people that have espoused this "thank you Microsoft" point of view have valid points, so it always seems like it's worth trying to examine them rationally. For example: yes, Microsoft is not the only company to do naughty things to competitors and even the alleged friend of us FOSS zealots - Google - is at base a company for making money. Yes, we all hold the dream of having an invention that changes the world and being recognised for it. Yes, standards are a good thing and having a unified desktop has helped developers create software in a way that having many competing operating systems would make difficult. Yes, Ford doesn't 'need' to consult its competitors or manufacturers of after-market accessories for their products if they want to change some detail of how their car is designed.
There are two problems with all of these things. Firstly, they're superficial - the comparison breaks down if you follow the analogy through. Ford doesn't need to consult its competitors explicitly because it already does implicitly - Ford knows that it has to offer competitive features or be left behind. Just because Google puts prices on ads and puts them in our faces and does deals with companies for where their listing is going to sit in various searches doesn't justify Microsoft's behaviour. Ideas are not monopolies and should not imply a monopoly on their execution.
But, more fundamentally, the problems with all of these things is that they miss a fundamental point that Free Open Source Software people realised early on: collaboration works much much better than competition. We live in a community of people; we live in societies with shared goals and ideals, ethics and past-times. Many things in life are not zero-sum games, and to portray everything as a win-or-lose, black-or-white scenario is not just incorrect, sometimes it's actually a form of cheating.
This point was driven home to me this afternoon when, just after having come out of an hour-and-a-half debate with one such Microsoft apologist, I read this exchange and it made sense. You simply cannot compare software to the real world, and you simply cannot compare the entire FOSS suite - the work of tens of millions of people all over the world in every profession and every category - with any other physical entity. Trying to stick to the car analogy is pointless because we're using a car, given to us for free, built by a whole range of people, which contains every possible combination of driving performance, style, comfort and efficiency - simultaneously! For free! And I can give you exactly the same car with minimal effort, absolutely legally. There's literally no analogy to it.
My observation here is that the car analogy, and many of the other analogies that get used to describe software and how it works, suits people who still belive in the politics and economics of scarceity. From the perspective of these analogies, Free Open Source Software makes no sense because it doesn't fit in the analogy. Strangely the people espousing these points of view don't see this as a sign that their analogy is broken, they see it as a flaw in the reasoning for Free Open Source Software.
Let's make it clear: Free Open Source Software works on the four principles of freedom espoused by the Free Software Foundation. They allow you to get software, use it, fix it if it breaks and improve it if you can, and share those improvements with other people. The key point unstated there which I think the Microsoft apologists are missing is that all this works on a community of sharing. The four freedoms make sense for you as an individual, but they are absolutely no-brainer logical when you are part of a large community of people that can help eachother. Proprietary software's principles only make sense when you are an individual, without any connection to anyone else using the software but with only the connection to the software vendor. Even before the internet that was untrue; the internet merely made the processes of being in a community - communication, contribution, sharing and co-operation - available to an audience many orders of magnitude larger.
In the heat of the moment, though, I did think of one fundamental flaw in
the car analogy that caused my interlocutor to reconsider his position. It
would be a completely different thing for Ford to change the specifications
of how after-market gadgets fit on their cars if Ford made 80% of the cars
on the market and (most importantly) if the size of the after-market
parts industry was ten to a hundred times the size of Ford's business. In
that light it doesn't look like fair play to change their specs so that they
can sell more brake-pads or steering wheel covers and everyone else has to
go back to the drawing board for six months. But, since that breaks the
analogy, it might not have made sense...
posted at: 17:21 | path: /tech | permanent link to this entry
Canberra Linux Users Group monthly meeting for May 2009
The first of many CLUG Linux Learners Meetings!
The meeting was, in general and in my opinion, a success. Lana Brindley gave the first talk, entitled "10 Reasons Why You Do Not Want To Install Linux. Ever.", which was (no surprises) really a "10 old myths about not using Linux and why you should ignore them" talk. It was clever, well presented and covered all the things Linux users get tired of explaining. Several times Lana would pose a myth about Linux and people would automatically call out objections or corrections - which I take to be a good sign that her talk dispelled the myths that us enthusiasts want cleared away.
My talk, unfortunately, I feel was doomed from the start. It was "Paul's Ten Tips About Bash", and the content was definitely useful to some people - and I think it says a lot about Linux users that even the most learned people in the room still learnt a few tricks and mentioned some that I didn't know. However, it wasn't a talk for everybody, and importantly it contrasted with Lana's number one point: that Linux is perfectly possible to use without ever coming near the command line. My disappointment is that I didn't think of this earlier - I got carried away by my own geekiness. It should have been "Paul's ten tips on avoiding the command line", which would have been something that many more people learned from. Heck, I could have learnt a lot putting that talk together.
I'll do it at the next Linux Learners meeting, which will be in August (I
think we'll set a schedule of doing them every three months and see how
that goes).
posted at: 18:48 | path: /tech/clug | permanent link to this entry
Canberra Linux Users Group Install Fest for May 2009
The Canberra Linux Users Group invites anyone in the Canberra region to
come along and learn more about Linux. We help you install Linux on
your computer, we teach you about how it works and the way to get around
a modern Linux desktop, and we help you fix the problems that have been
nagging you with your Linux system in the past. We can even demonstrate
what it looks like and why it's not as dangerous as it sounds if you're
not ready to install it just yet.
There's more information on my website, so
please feel free to email
me with your questions. If you want to come along and are interested
in having a sausage for lunch, please also drop me an email by Friday!
posted at: 22:45 | path: /tech/clug | permanent link to this entry
Installing and debugging Minimyth for fun and profit
In the ongoing quest to save power, I am moving my MythTV backend
onto my low-power home web server, and building a new low-power
frontend based on a fanless Via EPIA M board and the
Minimyth custom linux distro.
This is a cut-down system designed to boot off TFTP or NFS, but
can be also adapted to boot off a CompactFlash card, which is what
I'm doing (my firewall has a DHCP server but the web interface
doesn't allow me to set a TFTP boot option, and I can't be bothered
to work out PXE boot just this moment).
It's a very neat little package, with everything you could want compiled in, but this also means that setting it up is a rather complicated process. First you write a specialised config file, which has to go in a specific place. Then you unpack the various bits and pieces onto the CF card and run syslinux on it to make it bootable. Then you stick it in the machine and boot it, and if anything goes wrong you telnet (yes, telnet) into it and peruse its /var/log/messages to find out what went wrong. Then you take the CF card out, fiddle with the contents a bit on your own computer, plug it back in and see if that helped.
This is made somewhat frustrating by the lack of examples and somewhat minimalistic approach to explanation that the minimyth documentation takes. It also leans more toward the network boot process (to have no flash drive in the machine at all, and to allow you to run a writable root partition) and covers the flash install side somewhat minimally. The site also doesn't provide a sample / working / minimal minimyth.conf file, so you have to google around and womp up one on your own. Add to that the minimyth machine's habit of only bringing up its telnet connection (yes, telnet) about two minutes after you've booted it,
I started this nearly a week ago, and various delays and frustrations
have prevented me from documenting all the steps. But I'll try to get
more of the process documented soon.
posted at: 22:40 | path: /tech | permanent link to this entry
Canberra Linux Users Group monthly meeting for May 2009
The first of many CLUG Linux Learners Meetings!
This meeting is a 'fixfest' and learner session for people new to Linux or still finding their way around. (That's most of us!) We'll be having short talks about a variety of subjects but the majority of the night will be given over to people helping other people fixing problems and learning their way around Linux.
Lana Brindley will be starting the night with a talk entitled "10 Reasons Why You Do Not Want To Install Linux. Ever." and with a provocative title like that you can tell it's going to be interesting! Paul will then give a short talk on tips he's learnt in using Bash, the current standard command line shell in Linux.
You're welcome to bring your computer along but please email me
(paulway@mabula.net)
beforehand so I can get an idea of the numbers of machines involved.
posted at: 22:39 | path: /tech/clug | permanent link to this entry
CLUG Programmers SIG for May 2009
Last Thursday night we had Paul Fenwick from Perl Training Australia giving
two talks - "The Art of Klingon Programming" and "Awesome Things You've
Missed In Perl". I'd see the first one before at OSDC 2008, but Paul is
still constantly improving this talk so it's still worth seeing again. In
particular it's the examples that often have me saying "of course!" and
"how clever", as Paul introduces some subtle new feature or variation on
what he's said before that gives a new perspective on autodie's
usefulness.
"Awesome Things You've Missed In Perl" is a good way of updating seasoned Perl coders to the new things you can do with recent versions of Perl. It's more about the modules that have come out in recent years that make writing Perl much easier, such as Moose, autobox, and autodie (of course). But there's still much that Paul mentions that exists in Perl 5.10 that makes a coder's life easier; given/when, the smart match operator and named captures just for starters. For us people that still have a Camel book second edition on their desks (somewhat guiltily), it's an excellent refresher and reminder to get with the times. It also makes the transition to Perl 6 much easier.
The meeting was very well attended - 18 people - including three from the class that Paul was teaching. For me it was a wonderful "small world" moment as a friend of mine from Melbourne happened to be at the course - of course, my embarrassingly useless people memory caused me to have to ask her name. But it really was quite wonderful to see Louise again, albeit somewhat briefly. The main programmer for the water resources project that Paul was tutoring was interested to learn about the Canberra Perl Mongers group and will hopefully join and come along as a regular participant.
So, thank you Paul Fenwick for making this a really great night!
posted at: 11:37 | path: /tech/clug | permanent link to this entry
Ada Lovelace Day 2009
I feel moved
by
the
many
posts
on
Ada Lovelace Day
to
mention
a woman I know who has inspired me in my
love of computing and really taught me that there are no limits to what
you can do with a bit of perseverance. Many of the people talked about in
the posts I've linked to above are all deserving in their own right, and
many of them are well-known for their great works in the field. Maybe I'm
biased in talking about the person who has inspired me but I think it's
justified.
I want to tell you about my mum, Jane Fountain.
I can't link to her web page, because she doesn't have one. Her main activities on computers have been emailing friends, doing the job of secretary for the Society for Growing Australian Plants, and archiving her digital photos; she still occasionally struggles with the technology. It's been several months since her mobile phone account expired and she's only recently noticed - so she might not initially appear to be a good person to think of when dealing with technology.
But: my mum works as a teacher aide at the Chapel Hill State Primary School. Two years ago they got some Lego Mindstorms, and of course the teachers and teacher aides are supposed to teach the children how they work. So mum - on her own initiative - took the kit home, learnt the manual, and programmed it in the living room over a weekend. She taught herself how to program them, how to debug them, and how to program - having never learnt a programming language or gotten closer to programming them than watching her sons.
And, over the years, she's encouraged my brother and I to learn about computers and to use our abilities to their fullest. She might doubt her abilities some times but when she has a task to do she applies herself with a will. Fifteen years ago I can remember her remarking about a friend who knew the botanical names for plants and she stated that she'd never be able to do that - now she not only knows the botanical names for everything she plants but she gets frustrated with people who say it's difficult! She's artistic, intelligent, skilled at a huge range of crafts, and every time I visit she shows me some new clever thing she's thought of to help the children at her school learn and enjoy learning. And she's humble into the bargain :-)
In short, my mum continually inspires me to learn more, to apply myself, to
never say I can't do it, and to stick to it when I do. I think those are
qualities Ada Lovelace
herself would have admired.
posted at: 10:16 | path: /tech | permanent link to this entry
The intangible smell of dodgy
My Dell Inspiron 6400 has been a great laptop and is still doing
pretty much everything I want three years after I bought it. I fully
expect that it will keep on doing this for many years to come. Its
battery, however, is gradually dying - now at 39% of its former
capacity, according to the GNOME power widget. So I went searching
for a new battery.
I came across the page http://www.aubatteries.com.au/laptop-batteries/dell-inspiron-6400.htm, which I refuse to link to directly. It looks good to start with, but as you study the actual text you notice two things. Firstly, it looks like no person facile with Australian English ever wrote it - while I don't mind the occasional bit of Chinglish this seems more likely to have been fed through a cheap translator program. Secondly, it seems obvious that the words "Dell Inspiron 6400 laptop" have been dropped into a template without much concern for their context. Neither of these inspire confidence.
I was briefly tempted to write to the site contact and mention this,
but as I looked at some of the other search results it became
increasingly obvious that this was one in a number of very similar
sites, all designed a bit differently but using the same text and
offering the same prices. This set off a few more of my dodginess
detectors and I decided to look elsewhere.
posted at: 09:37 | path: /tech/web | permanent link to this entry
The Helpful Internet 0002
One of my work duties is to set up Nagios
monitoring on our servers. I intend to use the Nagios Remote Plugin
Executor plugin - 'nrpe' - and didn't want to futz around on work servers
possibly stopping things from working correctly, so I set it up at home.
(Yes, of course I have two servers at home, doesn't everyone?) I was
following the handy
guide to setting it up, when I hit this error (running nagios -v
nagios.cfg to verify the configuration):
Error: Invalid max_attempts, check_interval, retry_interval, or notification_interval value for service 'CPU Load' on host 'media' Error: Could not register service (config file '/etc/nagios/hosts.cfg', starting on line 41)
There's no setting you can get correct on this; changing the values doesn't seem to work, and if you remove one of them you get warned that they are required. Reading the version 2.0 documentation tells you that they're required but even if you obey it the above command still gives you the warning. This, by the way, is a hint that the problem lies elsewhere.
A bit of Googling found a few people with this error and not much more; one had someone 'helpfully' pointing out that the retry_interval keyword was only used in version 2 (which, of course, I was using). Our local Nagios expert came over and had a look, tried all the things I'd tried, and declared it unsolvable. After a bit more fiddling, I noticed that the service definitions in the PDF examples use the generic-service template, but the definitions in the localhost.cfg file (supplied by the EPEL nagios package) used local-service. I changed it in my new hosts configuration.
It worked.
And there it was, a second host in my Nagios display. Things looked even better after working out that, by default, nrpe's configuration doesn't allow commands to be given parameters by the server (as a plug for the obvious security hole), and therefore one had to set up specific command definitions for each command you wanted (rather than the standard Nagios configuration, which is to configure them in the service definition).
So the summary is that Nagios is a powerful tool, and its documentation
really needs some tender love and care. I mean, its standard install
instructions for Fedora ignore any possibility of packages and install
from source, and then disable SELinux. On a server! I shudder to think
what the other parts of the source package contain - maybe the CGI is
set up to allow all users by default.
posted at: 21:17 | path: /tech | permanent link to this entry
Error: insufficiently sincere headdesk
I discovered one of the servers that I manage had been placed in my hands
with SELinux turned off.
This, when SELinux is available, is a mistake, because if you ever need
to turn SELinux on again you will find that nothing in the file system has
the correct SELinux contexts, and everything will fail. Since this was a
server that didn't have anything important running on it, I decided to
reboot it with the /.autorelabel file in place and SELinux in permissive
mode, thus re-establishing the permissions while the server wasn't heavily
relied on.
After an hour with the server not appearing on the network, I started wondering what had happened. The console, it turns out, was displaying this message:
Creating root device Mounting root filesystem mount: error 6 mounting ext3 mount: error 2 mounting none Switching to new root switchroot: mount failed: 22 umount /initrd/dev failed: 2 Kernel panic - not syncing: Attempted to kill init!
Googling mount error 6 showed mostly complaints of disk and file system drivers not being compiled correctly, but further up the page (fortunately still on screen) I could see that the correct modules were being loaded. Pulling out my trusty rescue CD, I did a file system check. All fine. I tried recompiling the initrd file. All fine. I looked at the LVM information. All fine. Something niggled at the back of my head. I looked at the /boot/grub/grub.conf file. Then I discovered my error.
Concurrent to this reboot, I had renamed the logical volumes from the unhelpful (e.g. "LogVol00") to the sensible (e.g. "root_lv"). This can be done while the system is live (I discovered) so long as you also edit the /etc/fstab file to rename any device names. However, I hadn't renamed the devices in the Grub configuration - I usually make sure that the volumes are labelled and use root=LABEL=/root in the kernel parameters to set where the root volume is. So the kernel was looking for a non-existent block device and failing with the unhelpfully-named "mount error 6".
After a brief bit of enthusiastic head slapping, I fixed the Grub
configuration, rebooted and all was well. Hopefully the next time someone
encounters this error, they'll find this information useful.
posted at: 15:09 | path: /tech | permanent link to this entry
The 'helpful' internet
I've been wrestling with the new VMWare Server 2.0 interface for a number of
months now. Thwarting me has been the use of a "web" interface and its
complete failure to be able to log in. Each time I try I've been presented
with the dreaded and inexplicable error:
"The server is not responding. Please check that the server is running and accepting connections."
The 'help', if it can so be called, that people on the internet have provided for this has ranged from disabling SELinux, through disabling IPv6, to fiddling with various configuration in everything from VMWare to the /etc/services file. Almost universal in these pages is the fact that the person has done a couple of things (put some new line into /etc/vmware/locations, disabled iptables, installed xinetd) but none of them worked. Users are left either cluelessly following all of these things, hoping in a cargo-cult way that one of them might do the trick, or (like me, who eschews such thoughtless ritual) wondering what the real answer is.
Well, I finally found one suggestion that worked, for Fedora 10 on i386 at least. I can't say it will fix your problem, but it's at least a start. And it does seem to make sense with respect to what the problem seems to be - a failure in some part of the authentication process. Simply edit your /etc/pam.d/vmware-authd file to include these lines:
auth required pam_permit.so account required pam_permit.so
I'm not entirely sure what this does, which probably puts me back in the cargo-cult camp.
You will also need to fix a couple of the libraries' SELinux permissions to allow VMWare to use libraries which require text relocation:
chcon -t textrel_shlib_t '/usr/lib/vmware/hostd/diskLibWrapper.so' chcon -t textrel_shlib_t '/usr/lib/vmware/vmacore/libvmacore.so.1.0'And, once you've installed the VMWare viewer plugin for Firefox:
find /root /home -name np-vmware-vmrc-2.5.0-122581.so -print0 | xargs -0 chcon -v -t textrel_shlib_t
Hopefully this will help a few people who want to get VMWare Server working on
Fedora 10 without having to do crazy stuff (e.g. disable SELinux).
posted at: 17:00 | path: /tech | permanent link to this entry
LCA flies by
In certain circumstances, bringing an airplane, the sun and some clouds
into the proper relationship will show you an interesting phenomena -
a ring of brighter cloud, centred on the shadow of the plane. This
happens at the angle where the crystals in clouds perfectly reflect
the incident light back to you, and I'd love some optics physicist to
explain it to me one day. But it has the unusual property, if you are
close enough to the clouds, of focussing that small band - every detail
of that area stands out. Individual filaments of cloud are shown to you
before you swiftly move on to the next. If you watch one bit it fades
into dullness and its detail is lost, but if you keep your eye moving
every part of the cloud has its own delicate, infinitely detailed
beauty.
I found myself in just such a conjunction of plane, sun and cloud on my flight back from Hobart to Melbourne after Linux Conference Australia, still dazed by the early morning start to get to the six o'clock plane. In this contemplation-conducive state, I thought the image above was a good metaphor for the conference overall - each little bit brilliant but fading when compared to the next bit of brilliance, and the overall brilliance only capturable in the human mind, where the individual experiences can be overlaid rather than replaced and forgotten as in a movie.
I'll stop trying to wax lyrical, and while lyrical waxes someone else will note down some highlights the whole week of fun.
While it was a bit of a slog up the hill to the college from the Uni, it wasn't too hard and certainly got a few of us a bit fitter, myself included. The rooms were very nice, and despite being shunted out of my original room with other Canberrans I got to meet a bunch of new people which I always enjoy. Special thanks to Ian Beardslee for whiskey and perspective.
The venues were pretty good, but the fact that speakers had to hold radio mikes up to their faces led to a lot of pretty variable audio. Some people, like Tridge, Jeff Waugh, and Rusty already know how to project well - others were a bit shyer and/or uncertain how to speak to a microphone. The trick is to have it up near your chin - close enough to pick up every sound, but out of the direct breath path so that your 'P' sounds don't pop. The main point is that you are trying to get your spoken words across to everyone in the room and on the video, and that is much more important than feeling embarrassed. And never, ever blow into the microphone to test if it's on - tap it or scrape the mesh on the top instead. There's much less chance of damaging the pickup that way, or having an audio professional decapitate you with your own shirt for maltreating their equipment.
Being a speaker for the first time, I was really blown away with how well they treat speakers at LCA. You get picked up at the airport, you get your own (speakers) dinner and you get to go to the Professional Delegates Networking Session. So not only did I get to go to two very nice places to eat and see some of the attractions around Hobart, but I also got to pretend to be a professional. Being a part of the process that makes LCA great - the talks - is pretty awesome too. And having people talk to and email you afterward about the topic and ask more questions and have more discussion is even better. Still very happy with that.
However. In order to really rock as a speaker giving a "here's the coding project I've been working on" talk, I think you need one simple thing: results. There were a couple of talks - the High Def H.264 decoding in Intel GPU talk for example - that gave an overview one might give to technical management and showed us almost nothing in the way of actual code or working software. Compare this with the CELT talk, where Tim not only demonstrated why the code was so clever and why low latency was important, but demonstrated it right there. I don't really need a working demo, but I do need to see that the code is in use by real live people, not still on the drawing board. If drawing-board projects were the criterion for a good talk I would be occupying my own day at LCA. :-)
The conference dinner was very good - buffet style wins! The fund raising was also pretty awesome - although I'm not a big fan of the whole 'auction' thing when pretty quickly it has got out of the reach of any single person in the audience, I still think that it's an excellent example of why Open Source really does rule when we can raise over $40,000 for a charity from essentially a bunch of individuals with one tangible and a few intangible prizes (pictures in the kernel, people's integrity, etc.). If anything, the guy who spoke about the disease could have talked more about the research - most of the table I was sitting with was pretty bored through the 'here's some pictures of bad stuff' part but were riveted when it came to the 'and here's why it's a technically interesting problem' part.
The laptop case cover was well received but needs some work to straighten it out and stop it from cracking. It no longer attaches to the laptop - the tension on the outer surface simply pulls the catches back off again.
A judicious balance between coffee, V and water is what kept me going for most of the conference. I've found the 700ml Nudie bottles are light, easy to use, and contain enough water to keep you hydrated. It took me most of Monday to really feel like I was fully compos mentis.
I met lots of nice people in the LUG Comms meeting and more nice people in the LinuxChix lunch. I now owe Jon Corbet two beers, as part of a "I must buy you a drink for your excellent Linux Weekly News" plan gone horribly wrong, and Steve Walsh, Cafuego, James Purser and others need to be pinned down in a bar somewhere so I can buy them beers. Jon Oxer and Flame (who really should be called Black Flame) were excellent value, the keysigning was underpopulated but still worthwhile, and the sheer quantity of BOFs happening in spare rooms, in corridors, up trees and elsewhere were just too much for me.
The MythTV miniconference was a highlight - giving my talk at it was a lowlight because I should really have had much more technical detail; the lesson is "if you see someone suggesting a miniconference, only volunteer to talk on the subject if you have something that is at the generally high quality of Linux Conference talks". There were a few other MythTV talks that left me wanting a bit more detail, but there's no feeling quite like realising that all the technical people have left the room for your talk, and the only developer remaining is working on his presentation....
Overall, the quality of LCAs is still high, and I have no doubt that
Wellington will pull out all the stops for a top-quality LCA too. If
they can get their videos up a bit quicker than this year...
posted at: 08:20 | path: /tech/lca | permanent link to this entry
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