UK Linux User Groups

Sometime this spring (when it arrives) I will buy a new desktop system. It will probably have two block devices: a traditional SATA large capacity hard drive and a much smaller and faster flash drive.

The theory says that cheap flash drives are much faster and will even probably outlive mechanical spinning disks. Flash systems do slowly go bad so use wear-levelling software in the controller to maximise life. The other problem with flash drives is that they are relatively small, so a larger drive either in the box or on the network is required given how much space life takes up...

I've no plan to join the two drives together with LVM, it seems pointless, instead they will be kept separate and one mounted onto the other. At the moment most of my systems use ext3 except one box which uses ext3 and XFS.

If I install a new box from the Wheezy ISO I'm guessing I'll get ext4 as default. I gather this is the logical upgrade from ext3 until something fancy is really ready and it is not an all singing-dancing next generation filesystem. Does anyone know how it compares with XFS on large disks or flash disks?

I'll probably use ext4 on the flash disk (root & boot file systems) and XFS on the spinning disk (/srv) as it's where I'll dump my media files which aren't small and XFS is supposed to be good for that, unless it's not worth the effort.

I hope everyone is enjoying the long bank holiday weekend and, if you celebrate it, Easter. It’s strange to be celebrating the spring when there’s so much snow about, but there’s only one thing to do in these circumstances!

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This weekend I have mostly been reading Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time .

In modern times we divide the earth up into rings of lines, latitude and longitude, as wikipedia will explain.

Finding your latitude is easy, finding your longitude is a difficult process, and it was vitaly important when people started to sail large distances, the book contained lots of stories of sailors being suddenly suprised by the appearance of land - because they'd misjudged their position.

Having four ships, containing garlic, pepper, and other goods of value exceeding the total wealth of the UK, sink all at once was a major blow. Not to mention the large number of sailors who lost their lives.

There were several solutions proposed, involving steady hands and telescopes, etc, but the book mostly discusses John Harrison and his use of watches/clocks.

John Harrison was featured in Only Fools & Horses, as the designer of the watch that made Delboy & Rodney millionaires.

->Time on our hands

The idea of using a clock is that you take one with you, set to the time of your departure location. Using that clock you can compare the time to the local-time, by viewing the sun, etc. Calculating the difference between the two times allows you to see how far away, in degrees, from your port, and thus how far you've traveled.

Until harrison came along clocks weren't accurate enough to keep time. His clocks would lose a second a month, until then clocks might lose 15 minutes a day. (With more variations depending on temperture, location, and pressure. Clearly things like pendulum clocks weren't suitable for rocking ships either.)

All in all this book was a great read, there were mentions of Galilao, Newton, and similar folk who we've all heard of. There was angst, drama, deceit, and some stunning craftmanship.

Harrison was a woodworker, and he made his clocks out of wood (+brass where necessary). Choosing fast/slow-grown wood depending on purpose, and using wood that secreted oils naturally allowed him to avoid lubrication - which improved accuracy, as lubricants tend to thin/thicken when temperature/pressure change.

A lovely read, thank you very much.

In other news I received several patches for my templer static-site generator, and this has resulted in much improvement. I've also started using Test::Exception now, and slowly updating all my perl code to use this.

A few weeks ago I bought a pair of Devolo 500AV Ethernet over mains units to replace/extend a pair of 200AV units I already had. Someone asked if could use iperf to see how much faster they were.

To baseline what I had I ran the test from my desktop to my server over a 1 Gig switch and the most I could get was a feeble 333 GBit/s. I then tried from my laptop to the server on the same switch and that got a much better 740 GBit/s. The Marvell Yukon card on my desktop is a PCI device and the JMC250 in the laptop is a PCI-e so that may partially explain the differences.

Trying my laptop to the server via a 200AV/500AV/Gig-E switch gave a throughput of 56 GBit/s - about what you would expect. I then tried the laptop through a combination of 500AV/500AV/Gig-E but that wouldn't work as the JMC250 refuses to detect the 500AV. I then tried the laptop with different switches, it refuses to talk to my second Gig-E switch or my old Ethernet hub.

After some Goggling it turns out that the JMC NIC is a bit fussy and often fails to auto-negotiate with some "green" Gig switches, such as in the 500AV or my newest GBit switch, but is happy with older switches and plain Fast Ethernet. If you manually set the speed with ethtool then it's okay. I downloaded the latest driver from JMC and that is a bit better but while it will connect to my 500AV and my newer Gig-E switch automatically, it won't negotiate the correct GBit speed, falling to the older 100 MBit setting.

Footnote: The JMC250 is a 1 Gig Ethernet NIC from JMicron Technology Corporation, not something from the Jupiter Mining Corporation...

Someone asked me to test the speed of some Devolo 500AV ethernet over mains units I have as compared with some older 200AV units. In preparation I ran a simple test from my desktop box (that I plan to replace) to my server showed a throughput of about 333 MBit/s over a GigE switch. My younger laptop to the same server with a more modern (but still cheap) NIC gets 727 MBit/s to the same server over the same switch.

The desktop is using the common (at the time) Marvell Technology Group Ltd. 88E8001 Gigabit Ethernet Controller (rev 13) and the skge driver. ethtool reports all is well and that it's running at 1000 Mb/s as expected, but it clearly can't manage that on a simple iperf check.

Now I am planning on replacing the box anyway but just wondered if anyone knows and good tuning tips for Gig Ethernet?

Tags: ethernet, skge

We have asked Moray Allan, one of the three candidates for DPL elections 2013, to tell our readers about himself and his ideas for the Debian Project.

You can also read the interviews to the other two candidates: Lucas Nussbaum and Gergely Nagy.

Please tell us a little about yourself.

I'm Moray Allan, from Edinburgh in Scotland. I'm 32. After working in academic research for a few years, I'm now working freelance on a wide mixture of topics, with recent projects in Indonesia, Romania and Kuwait. When I'm not working, I'm likely to be found walking through a city or the countryside, or otherwise relaxing at home reading a novel in French or Spanish.

What do you do in Debian and how did you started contributing?

In recent years, most of my Debian time was taken up organising the annual Debian conferences. But I still have a load of packages, mostly connected to an upstream Linux-on-handheld-computers project I was working on before I joined Debian to create packages for it.

Why did you decide to run as DPL?

I've been involved in Debian for about 10 years now, including working for the last few years in DebConf in a way similar to how the DPL acts within overall Debian. Previously I'd ruled out running due to lack of time, but currently I'm in a more flexible work situation. It seems the right time to put myself forward, and see if the ideas in my platform interest project members.

Three keywords to summarise your platform.

Transparency, communication, openness. (Three ways I'd like us to think about teams in Debian.)

What are the biggest challenges that you envision for Debian in the future?

I think the biggest challenges are for free software in general.
End-users are moving to more closed hardware -- will our software be able to run on the phones and tablets people are shifting towards? At the same time, end-users and server users are moving to "the cloud", and often depending more heavily on non-free infrastructure outside their own control.

What are, in your opinion, the areas of the project more in need of technical and/or social improvements?

In my platform I give a few ideas about teams and delegations, coordination and mediation, and both internal and external communication, including more organised fundraising. These are areas where I think relatively simple changes can give big benefits.

Why should people vote for you?

I have proven leadership experience within Debian, as I've been working on coordination and mediation tasks for some years already. At the same time, I do regular packaging work, and work in other parts of Debian like the press and publicity teams, so I'm in touch with the experience of normal Debian contributors. People should vote for me if they support my platform, which is about coordination-level changes that I would have no mandate or authority to push through unless I am elected.

Name three tools you couldn't stay without.

APT, emacs, ssh.

What keep you motivated to work in Debian?

I've used Debian on all my computers for a long time, and by now working on the distribution myself feels a natural part of that.
Fortunately I'm constantly positively surprised by Debian and by the Debian community.

Are there any other fields where you call yourself a geek, besides computers?

Certainly history (such as the eastern Mediterranean region in late antiquity), languages (including dead ones) and music (especially Josquin to Monteverdi).

We have asked Lucas Nussbaum, one of the three candidates for DPL elections 2013, to tell our readers about himself and his ideas for the Debian Project.

You can also read the interviews to the other two candidates: Gergely Nagy and Moray Allan.

Please tell us a little about yourself.

Hi! I'm a 31 years old french computer geek. In my day job, I'm an assistant professor (Maître de Conférences) of Computer Science at Université de Lorraine.

What do you do in Debian and how did you started contributing?

Like many, I started contributing to Debian by creating and maintaining packages for my own software, in the Ruby team. Then, I discovered that, even if it's not so obvious from the outside, there are a lot of areas in Debian that could use more contributors. So I just started to contribute to more and more things.

There's a list of things I did in Debian in my platform. What I have been doing recently is:

• rebuild all packages in Debian on a regular basis in order to identify packages that can no longer be built, and file bugs accordingly. In order to do that efficiently, I use cluster and cloud resources (more info)

• develop and maintain Ultimate Debian Database, a data aggregator that collects data in most Debian services so that it is possible to expose it in interesting ways (e.g. find release-critical bugs affecting popular packages).

• write and maintain a Debian Packaging tutorial, (packaging-tutorial package), to provide an easy-to-read introduction to packaging in Debian.

Why did you decide to run as DPL?

Two main reasons:

• Most of my Debian contributions aim at addressing problems at the distribution scale (cross-distro collaboration, Quality Assurance, data-mining). Being DPL is a great way to contribute to Debian at this level.

• the DPL campaign is a great time in Debian where we discuss the project's problems, politics and visions. Being a candidate is in itself a way to contribute to Debian (though it would be better if we had those discussions outside DPL campaigns too).

Three keywords to summarise your platform.

(re-)make Debian the center of the Free Software ecosystem; foster innovation inside Debian; reduce barriers to contributions

What are the biggest challenges that you envision for Debian in the future?

I often have the impression that the project is losing momentum, positive energy, and slowing down. It feels like we are living on the benefits of the past. A lot of very cool things happen in the Debian ecosystem, but very often outside the Debian project (in derivative distributions).

Debian should aim at reinforcing its position in the center of the Free Software ecosystem: it should be the main active intermediary between upstream projects and final users. To achieve that, we need to reinforce the visibility and the impact of Debian. This is extremely important because the values we fight for as a project are often neglected by our derivatives.

What are, in your opinion, the areas of the project more in need of technical and/or social improvements?

Fostering innovation inside Debian: we should be more welcoming towards innovation and experiments inside the project. Often, we merely tolerate them, and bureaucracy makes them hard and slow to conduct. As a result, people tends to innovate outside the Debian project.

Making it easier to contribute to Debian: we compete with more and more projects to attract contributors. While we are already quite good at welcoming new contributors with good documentation and mentoring (much better than people usually think), there's still a lot of room for improvement.

Why should people vote for you?

A great thing in Debian's voting system is that you don't vote "for" or "against" a specific candidate. Instead, due to our use of the Condorcet method, you rank candidates (and also indicate those who you consider suitable for the role by ranking a virtual "None of the above" candidate).

Why am I a good candidate? My previous contributions to Debian show that I have a pretty good understanding of the inner workings of the project, and that I have a track record of managing projects successfully inside Debian. I think that those are two required qualities for a DPL.

Name three tools you couldn't stay without.

vim, mutt, ssh.

What keep you motivated to work in Debian?

Debian is a fantastic project from a technical point of view (focus on technical excellence, lots of interesting challenges), but also from a social point of view: the Debian community is a great community where I have lots of good friends. Also, what's great when you contribute to Debian is that your work has a real impact, and that you see people using stuff you worked on everywhere.

Are there any other fields where you call yourself a geek, besides computers?

I'm not sure this really qualifies as "besides computers", but I've gotten very interested in the OpenStreetMap project lately. I very much enjoy exploring unmapped areas on a mountain bike. It feels like being Christopher Columbus or Marco Polo, but 20 minutes from home. ;) The OpenStreetMap and Debian projects also share many values, such as a great attention to quality and details.

We have asked Gergely Nagy, one of the three candidates for DPL elections 2013, to tell our readers about himself and his ideas for the Debian Project.

You can also read the interviews to the other two candidates: Lucas Nussbaum and Moray Allan.

Please tell us a little about yourself.

I was born in Hungary, a little bit over three decades ago, as a son of a biochemist and a pharmacist, who gave me the name Gergely Nagy (however, online - and offline too by now - I'm mostly known by my nickname, algernon).

I went on to study human arts (hungarian grammar & literature, in particular), and to support this passion, I work as a software engineer, one who gets paid to work on free software. As such, I'm in a fortunate situation where my hobby supports my passion, and my hobby aligns well with my Debian work too.

What do you do in Debian and how did you started contributing?

At the moment, apart from maintaining a few packages, I'm doing a few other, mostly invisible things, like reassigning misfiled bugs so they don't end up being forgotten; or review newly uploaded packages before they enter the archive, making sure we are allowed to distribute them, and that their quality is up to our standards. I used to do quite a lot of other things, but I chose to spend the past year mostly invisible, learning.

I started contributing by packaging an editor I was using at the time, but quickly ended up adopting another package - things escalated from there quickly.

Why did you decide to run as DPL?

There were two reasons that motivated me to run: one is that I believe I can bring something new to the table, that I can help Debian expand in new directions. The other reason is that I'm always on the lookout for new ways to contribute back to Debian, and being the project leader is a position where I believe I could contribute most at this point in time.

Three keywords to summarise your platform.

Non-technical contributors.

What are the biggest challenges that you envision for Debian in the future?

The biggest challenge is growing up, to become more than a group of computer geeks creating an amazing distribution. To become a community of a wide variety of people, where both computer geeks and art geeks feel equally at home. Yet, at the same time, where we as a project, keep our focus straight, and be the champions of Free Software.

We just need to realize that there's much more to Free Software than the software itself.

What are, in your opinion, the areas of the project more in need of technical and/or social improvements?

I believe that while we do have many areas where we could use technical improvements, we are reasonably safe there, because we do have very skilled technical people to help us solve these problems. We can make our tools better, we can develop our infrastructure better to aid us even more - and so on and so forth. While we need work on many areas, we're on the right track there.

However, when it comes to social issues, we're at a loss. We have serious trouble keeping certain topics civilised on mailing lists, we have trouble attracting women, and we have trouble reaching people who are not naturally exposed to Debian (or Free Software). We could really use a more diverse community, but that requires us to overcome quite a lot of social roadblocks, so to say. Outreach is one particular area where we need much more technical and social improvements.

Why should people vote for you?

People should vote me, because they found my platform, my answers on debian-vote@, and my ideas and goals convincing and worthy to pursue. People should vote me, because they trust I'll be able to serve the project well.

Name three tools you couldn't stay without.

Emacs, git and a pencil. Because with these three, I can pretty much do anything.

What keep you motivated to work in Debian?

The community. Over the years, I had the good fortune to meet with a lot of people I hold in high esteem, whose enthusiasm and motivation I found inspiring. For any other common goals Debian and I may share, in the end, it is the people within Debian that keep me motivated.

Are there any other fields where you call yourself a geek, besides computers?

I'm not quite there yet, but I'm working hard on becoming a human arts geek, or at least a geek of the hungarian language.

It’s been quite a week. But in a really good way. It started off last Sunday with a trip to see Richard Herring‘s latest show, “Talking Cock.” The subject matter should be obvious from the title, and it says something about the topics he has covered in the past that this is probably the lightest and fluffiest of the four shows that I’ve seen. It’s very enjoyable and not particularly crude.

I spent the middle of the week at the Photography Farm, a three day residential workshop run by the award-winning Lisa Devlin. I’ll write more about it and share some of my photographs in a couple of weeks, but for now suffice it to say that it was a challenging, fun and exhausting time. It will take me a while to fully absorb it all, but I know it will have a huge impact on my wedding photography. But most importantly I met some fantastic new friends.

This weekend was Big Finish Day 3 in Barking, where I was proud to be representing The Doctor Who Podcast, wearing one of their rather snazzy t-shirts. Laura and I recorded lots of interviews with contributors to Doctor Who and Big Finish. I won’t list them all here to preserve some element of surprise, but I’m grateful to so many people for giving up their time to talk to us.

Then back home, via a whistle-stop visit to Emma Jane and James Westby’s wedding reception in Nottingham, where I managed to fall over spectacularly on sheet ice less than two seconds after warning others not to do the same. Ow.

The last thing I wanted on Sunday evening was to go back out into the cold, but I’m glad I made the effort to see Mark Thomas’ show “Bravo Figaro.” It’s a performance piece rather than stand up, and is in turns funny, dark and touching.

And now, I’m off to bed.

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I use get-iplayer to download TV programs so I can watch them on the devices that suit me, when it suits me. What follows is how I install get-iplayer on a headless Debian 6.0 server I have a home. The server is question is really low powered so building from source was not an option.

In order to install the latest version of get-iplayer (currently 2.82) on Debian Squeeze a couple of additional package respositories need enabling.

• Debain Multimedia
• Debian Backports

Enable the Debain Backports repository by adding the following line to /etc/apt/sources.list.d/backports.list.

deb http://backports.debian.org/debian-backports squeeze-backports main

Enable the Debain Multimedia repository by adding the following lines to /etc/apt/sources.list.d/multimedia.list.

deb http://www.deb-multimedia.org squeeze main non-free deb http://www.deb-multimedia.org squeeze-backports main

Update the repositories.

sudo apt-get update

Install the deb-multimedia-keyring package.

sudo apt-get --allow-unauthenticated install deb-multimedia-keyring

Install get-iplayer (currently v2.78) from the official Debian repositories, this will also install the dependencies.

sudo apt-get install get-iplayer

Install the get-iplayer suggested packages.

sudo apt-get install ffmpeg rtmpdump libdata-dump-perl libid3-tools libcrypt-ssleay-perl libio-socket-ssl-perl

I have seen it suggested that mplayer should also be installed. I've not determined if that is an absolute requirement. But this is how to install it on a headless Debian computer.

sudo apt-get --no-install-recommends install mplayer

Finally, upgrade get-iplayer to v2.82.

sudo apt-get install libmp3-tag-perl libxml-simple-perl wget http://ftp.uk.debian.org/debian/pool/main/g/get-iplayer/get-iplayer_2.82-2_all.deb sudo dpkg -i get-iplayer_2.82-2_all.deb

At this point get-iplayer should be good to go and the get-iplayer website and man get-iplayer will assist you.

References

• http://www.infradead.org/get_iplayer/html/get_iplayer.html
• http://www.deb-multimedia.org/
• http://backports-master.debian.org/
• http://lists.infradead.org/pipermail/get_iplayer/2012-June/003065.html
• http://tech.leeporte.co.uk/get_iplayer-under-debian-squeeze/