mkdir Linuxing – the Linuxing In London’s newsletter issue 1, January 2017

1. Welcome

Welcome to the second edition of our newsletter and the first of 2017!

At Linuxing In London we want to popularise the increased use of free open source software and Linux. We meet every month at the premier technical venue, CodeNode, close by Moorgate and Liverpool Street stations.

Our aim is to be educational and inclusive, we want people to discuss open source technology and for everyone to benefit from it.

We hold a wide range of presentations and our newsletter reflects that. We are still experimenting with its format and would welcome intelligent, but pithy contributions of about 200-300 words from our readers.

In this edition we have:

our future events,
a retrospective on 2016,
links to speakers’ material and slides,
David’s witty comments on software, people and happenings,
along with a contribution from Okash Khawaja.
concluding with a big thanks to all of our supporters (large and small).

And may we wish you all a happy New Year and terrific 2017!

Brian Byrne


2. Future Linuxing In London Events

We have an up and coming event tonight, Thursday, 19th January 2017 at Skills Matter and many others planned for 2017.

Thursday, 16th February 2017 – TDB

Provisional dates: 16th March, 20th April and 18th May 2017.

Please do remember that all Linuxing in London events are free to attendees, and it is purely a voluntary effort.

3. A retrospective

2016 was a tremendous year for Linuxing in London. We established ourselves as the largest educational and most inclusive Meetup in London, with nearly 680 members.

We started in late May 2016 with presentations by IBM and SUSE, who generously provided a miniature helicopter for our free raffle.

June 2016 saw Richard Collins of Canonical talk about Linux on tablets and devices. Dr. John Hearns gave a scintillating talk covering racing cars, Formula 1 and high-performance computing.

In July, Ian Partridge tackled the Swift language and Linux. One of the most memorable talks of the year was from Alina Swietochowska. It traversed CentOS, Red Hat and the intricacies of RHEL distributions. It is well worth viewing again.

August 2016 was a busy month with an educational Linux 101 class and an evening of IoT, Raspberry Pis and the importance of system logs from Ian Massingham, Viktor Petersson and Péter Czanik respectively. Viktor and Screenly generously donated a few Raspberry Pis to our free raffle.

By September 2016 we were in our stride. We had fun, stimulating talks and at the end of the evening free prizes for our members. Sometimes it was T-shirts, powerbars and sometimes complete IoT systems. All free in our raffle. Josh Elijah showed off his marvellous robotics kits. Their intricate design fascinated our members and their peculiar crab style of walking was a joy to behold. Anthony Kesterton of Red Hat tackled the tricky subject of security and SELinux. Later on John Boero looked at Puppet on Linux: Past, Present, and Future. We enjoyed food and drink courtesy of Red Hat and Puppet.

October 2016 was a month full of activity with a special QA-sponsored evening of Alina Swietochowska’s wisdom. One lucky member won a free course valued at about £2600, plus all of the assorted swag and prizes we could give out. Many thanks to QA.

Late October we were fortunate to have Andy Clark talking about dragons. Dawn Foster on Gource and Linux kernel, finishing the evening off with Fedora on Raspberry Pi by Red Hat’s Peter Robinson. Andy generously contributed a CapTIvate MCU Development Kit to our free raffle.

November 2016 was a stupendous month. Red Hat chose to sponsor a whole night and we had a Special Evening of Red Hat at Linuxing in London!

They supplied excellent speakers, food and drink. Not to mention the three full Raspberry Pi kits given away to our members in the free raffle. Fabio Alessandro Locati spoke about Ansible. Phil Griffiths gave a bluffer’s guide to relax-and-recover.  Alberto Ruiz looked at the history of Linux and GNOME, Fedora and RHEL. Anthony Kesterton, a regular, showed how OpenShift could scale up to 10,000s containers.

There was a mountain of give-aways, T-shirt and goodies, and then we headed off for drinkies in the Skills Matter bar, courtesy by Red Hat.

December 2016 was our Xmas event and we have to thank Rackspace and IBM for the evening’s food/drink.

Igor Ljubuncic of Rackspace, gave a spell-binding talking on Application Profiling, Or How I Stopped Worrying and Learned to Love the Tweak – Director’s Cut. Herb Daly, University of Bedfordshire talked about the Open Mainframe Project. A IBM team (David Spurway, Andrew Laidlaw and Chris Parsons) covered OpenPOWER, OpenStack, and Open APIs. Finally, Bill Turner spoke on Christmas philosophy.

All in all, we had some brilliant talks, gave away plenty of swag and prizes. Betty Junod of Docker shipped over some goodies from the US especially for the night.

By my rather conservation reckoning in 2016 we gave away in excess of 100+ T-shirts, two Raspberry Pies (thanks to Viktor), a BananaPi (Herb Daly), a course worth £2600 (QA) and three full raspberry Pi kits (Red Hat and Alan Fewell). More of 40+quality battery bars (Rackspace and Rob Freeman), numerous speciality water bottles, Google glass types, QA USB sticks and many, many Power bars. Plus pen, stickers, notepad, a few books on Raspberry Pi and Alina’s handy Vim guides.

That is just what I recall, I know have missed a lot off too. But more importantly we gave people the sense that technology doesn’t have to be boring or dry. We laughed, told jokes and enjoy the fine hospitality of Wendy and Nic.

We had the cream of technical specialists from IBM, Red Hat, SUSE, Canonical, Puppet, QA, Rackspace and AWS, along with aficionados of Linux and open source.

2016 was great and 2017 is going to be better!

4. Materials from Linuxing In London events

Most of our events at Skills Matters are recorded. The archive of our Meetup events can be found here: Linuxing in Londonpast events

4.1 Slides and more

May 2016

IBM Developer Tools:

IBM Research:

IBM Systems:

SUSE OpenStack Cloud

SUSEcon, their annual technical conference

SUSE Studio

June 2016

Ubuntu for mobile

Supercomputing with Linux by Dr. John Hearns

July 2016

Swift and Linux – now and the future by Ian Partridge

The Swift language, previews.

IBM developer on Swift

Centos 7 vs Centos 6, System Admin, tricks and traps, a brief introduction by Alina Swietochowska.

11th Aug 2016

Linux 101 repo.

30th Aug 2016

Getting started with AWS IoT on Raspberry by Ian Massingham

Lessons learned from Screenly @ Linuxing in London by Viktor Petersson

Scaling your logging infrastructure using syslog-ng by Peter Czanik

22nd September

Liked EngiMake’s robots? They have a Kickstarter.

John Boero’s Puppet slides, September 2016:

Cats Vs Dogs: Securing Linux with SELinux by Anthony Kesterton.

19th October

Protect your actions: su, sudo or root login by Alina Swietochowska

Journald – a friend or a foe? by Alina Swietochowska.

25th October

How I entered a £5000 design challenge by accident by Andy Clark.

Using Gource to visualize Linux kernel data by Dawn Foster.

The road to Raspberry Pi on Fedora by Peter Robinson.

29th November

Automating your infrastructure with Ansible by Fabio Alessandro Locati

Who’s got your ReAR covered? (A bluffers guide to relax-and-recover) by Phil Griffiths

What has the desktop ever done for us? by Alberto Ruiz

“And then we have 10,000’ using OpenShift to scale up your container development” by Anthony Kesterton

14th December

Application Profiling, Or How I Stopped Worrying and Learned to Love the Tweak – Director’s Cut by Igor Ljubuncic.

Tinkering with a Banana Pi, some observations by Brian Byrne.

Redefining Big Time Linux: The Open Mainframe Project by Herb Daly

OpenPOWER, OpenStack, and Open APIs – how IBM is bringing Open to the Enterprise by David Spurway

Node-red Tutorials and getting started material:
Source code to the nodes:
Node-RED itself:
The Watson nodes, the IBM Slack channel:

5. Heap dump – Brian’s brief editorial

Many think that Linus Torvalds’ greatest contribution was the Linux kernel, but I would argue it is Git, and Git has had a wider impact on how we do modern software development.

Nearly every company uses Git now, even Microsoft have built it in to their flagship Visual Studio. We share our code mostly by Git, in one form or other. That is a point to contemplate.

Git, not Linux, has conquered the world of software!

Editor’s note: Sorry, I was struck down with a chest complaint for over 5 weeks along with the Xmas festivities resulted in a much delayed newsletter.

6. A thank you from QA


QA, are pleased to have sponsored a Linuxing In London event. We hope you enjoyed the drinks and pizza and found Alina’s presentations insightful and beneficial. If you would like a copy of Alina’s presentations click here to download. We have an extensive curriculum including Linux and Red Hat courses for wherever you are in your learning journey.

7. Feeling slightly artistic?

Linuxing In London are looking for volunteers to help out, and a free designer for our Github-hosted web site. So if you fancy being artistic with Github’s Jekyll or just want to lend a hand please contact Brian or David.

8. Red Hat Tech Talks


Red Hat runs a series of engaging technical talks in London at their HQ by Monument. I recommend them.

9. Dave’s notes

Wahoo. Issue two!

Those fortunate enough to attend OSCON Europe (http://conferences.oreilly.) might have arrived early enough to have seen Canonical founder, Mark Shuttleworth, speaking about SNAPS ( Whilst he interviewed the founder of Rocket.Chat ( I was already thinking how useful it seemed. Already available on Ubuntu (of course), it’s been snapped up by (the jokes just get better!) Arch, Debian, Fedora. Coming soon to CentOS, Elementary, Gentoo, Mint, OpenSUSE, OpenWRT, and RHEL. There are now approaching 500 Snaps: from WebRTC, Minecraft, NextCloud, Tor, Postgres, Handbrake, Rsync, HexChat, Vuze and many more. Still feels *new* but the intention is to create more standalone, sand-boxed apps, no matter the distro. Would love to hear if anyone has had a tinker with them already!

If your relatively new to programming or hope to dive deeper in Linux, look not further than the language C. Linux is primarily written with it. MagPi released a free ‘C Essentials’ issue for the Raspberry Pi and is not restricted for use on a Pi. A great resource for anyone just starting out with the programming language C. The PDF is free to download and you can purchase a print version is that’s your preferred way to consume a magazine I also checked out Wikibooks which jumps to more depth if you need a further push. I found it via the incredible list of Free Programming Books on Github and have started working through the examples. Can’t recommend this enough!

10. Contribution: Tweaking I/O Scheduler by Okash Khawaja

I/O scheduler works on block I/O layer which sits under the filesystem and communicates with a block device such as hard disk drive. The job of the scheduler is to make sure reads and writes to the disk are handled in most efficient manner. The definition of efficient however depends on the use case. Linux allows users to choose I/O scheduling algorithm. Here are the standard options. Values in brackets are how you specify them to the kernel.

– Deadline (deadline): puts a max deadline of 500ms (configurable) for reads to be serviced

– Anticipatory (as): improvises on Deadline by computing heuristics

– Complete Fair Queuing (cfq): each process gets its own queue of I/O requests and the queues are serviced in round-robin fashion, 4 requests (configurable) at a time

– Noop (noop): a basic FIFO scheduler without any seek optimisation or read preference

To check scheduler algorithm on a running system, cat /sys/block//queue/scheduler. To change scheduler at runtime: echo > /sys/block//queue/scheduler. Scheduler can also be specified via kernel command line argument `elevator` at boot time, e.g. elevator=noop.

Usually you want reads to happen faster than writes. In desktop environment, you want reads to take no longer than a certain maximum number of milliseconds. In HDDs you want to minimise number of seeks, i.e. read or write contiguous sectors in one go whereas in flash devices, which have truly random access, this seek optimisation is not required. Deciding on the policy might be hard and use-case dependent but true to its spirit, the kernel does provide with mechanism to change it.

11. David’s bits

I managed to squeeze in the Sunday before OSCON for Community Leadership Summit ( It was a really fun unconference and a truly encouraging moment to hear stacks of people empowering people. Whether in their own internal teams, open source projects, consultancies, startups, enterprises, or civil service, the message was loud and clear: Open Source is still evolving and is more diverse than ever.

We don’t have all the answers, but collaborative ways of working: from Mozilla’s ‘Open Innovation’ ( are helping bridge the chasm.

12. Jobs


I am often asked about jobs from our members. Many are very senior people, with decades of experience, looking for opportunities in a changing world.

To help our members I approached Snap! as they have a different way with recruitment and human resources. They were courteous enough to sponsor us, so please do contact them and see if they can help you.

13. Thanks

Bringing Linuxing In London together has been challenging as we took on a new format.

Traditionally, many British Linux groupings favoured obtuse techo-natter over a pint and an evening of drinks, or a summit of a selective few with little wider impact on the real world. Linux gatherings have, in the past, been a bit too elitist for my taste.

Whereas we have tried to be as inclusive as we can and focus on education, bringing quality speakers to our members and providing a fun time as well. It has taken a lot of effort to make it happen, but as with most good things in life it has been a team effort.

None of this would have been possible without the help, advice and assistance of many people along the way. If I missed you off by mistake, sorry. 🙂

None of this would have been possible without the help, advice and assistance of many people along the way. If I missed you off by mistake, sorry. 🙂

Firstly, erg bedankt to Wendy Devolder and Nic, the most inimitable of hosts at Skills Matter!

Next, David Ross’s sterling support for Linuxing In London from the outset, his encouragement and paying for the raffle tickets can not go unnoticed! Simon Schofield, a real modest but incredibly good electronics engineer, has always been supportive.

Gerard Sans, Ian Massingham and Luca Mezzalira, real experts in modern technology and of great encouragement.

Alan Fewell of Red Hat was instrumental in encouraging the creation of Linuxing In London. Andrew Laidlaw of IBM was one of our first speakers, regular attendee and stout supporter. Simon Briggs and Stephen Mogg of SUSE.

Special thanks to QA, Lauran, Alina, Sukh, Josh, John, those Red Hatters, Alan and Anthony, John, Dawn, Igor, Rob, Ian Partridge, Team IBM, Bill, many others! Not forgetting Russell, Megan, Fraser, Lovella, Herman, Michael, Nicole, Sophie and Enrico and everyone else at Skills Matter.

Maggie Cranford and Margaret Gold have been a constant fount of encouragement and gentle advice.

We have support far and wide and must mention Betty Junod of Docker who sent lovely t-shirts and goodies for our Xmas events all the way from the States.

This newsletter and Linuxing in London would not have been possible without the help of those lovely people at Skills Matter and our Linuxers, congratulate yourself!

Finally, thanks to Okash Khawaja for an interesting article.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s