Planet HantsLUG

June 23, 2015

Debian Bits

Reproducible Builds get funded by the Core Infrastructure Initiative

The Core Infrastructure Initiative announced today that they will support two Debian Developers, Holger Levsen and Jérémy Bobbio, with $200,000 to advance their Debian work in reproducible builds and to collaborate more closely with other distributions such as Fedora, Ubuntu, OpenWrt to benefit from this effort.

The Core Infrastructure Initiative (CII) was established in 2014 to fortify the security of key open source projects. This initiative is funded by more than 20 companies and managed by The Linux Foundation.

The reproducible builds initiative aims to enable anyone to reproduce bit by bit identical binary packages from a given source, thus enabling anyone to independently verify that a binary matches the source code from which it was said it was derived. For example, this allow the users of Debian to rebuild packages and obtain exactly identical packages to the ones provided by the Debian repositories.

by Ana Guerrero Lopez at June 23, 2015 12:00 PM

June 22, 2015

Anton Piatek

Hello Pace

After leaving IBM I’ve joined Pace at their Belfast office. It is quite a change of IT sectors, though still the same sort of job. Software development seems to have a lot in common no matter which industry it is for.

There’s going to be some interesting learning, things like DVB are pretty much completely new to me, but at the same time it’s lots of Java and C++ with similar technology stacks involved. Sadly less perl, but more Python so maybe I’ll learn that properly. I’m likely to work with some more interesting Javascript frameworks, in particular Angular.js which should be fun.

The job is still Software Development, and there should be some fun challenges with things like allowing a TV set top box to do on demand video content when all you have is a one-way data stream from a satellite, for instance, which make for some interesting solutions. I’m working in the Cobalt team which deals with a delivering data from the TV provider onto set top boxes, so things like settings, software updates, programme guides and on demand content and even apps. Other teams in the office work with the actual video content encryption and playback and the UI the set top box shows.

The local office seems to be all running Fedora, so I’m saying goodbye to Ubuntu at work. I already miss it, but hopefully will find Fedora enjoyable in the long term.

The office is on the other side of Belfast so is a marginally longer commute, but it’s still reasonable to get to. Stranmillis seems a nice area of Belfast, and it’s a 10 minute walk to the Botanical gardens so I intend to make some time to see it over lunch, which will be nice as I really miss getting out as I could in Hursley and its surrounding fields.

by Anton Piatek at June 22, 2015 02:53 PM

June 21, 2015

Steve Kemp

We're all about storing objects

Recently I've been experimenting with camlistore, which is yet another object storage system.

Camlistore gains immediate points because it is written in Go, and is a project initiated by Brad Fitzpatrick, the creator of Perlbal, memcached, and Livejournal of course.

Camlistore is designed exactly how I'd like to see an object storage-system - each server allows you to:

  • Upload a chunk of data, getting an ID in return.
  • Download a chunk of data, by ID.
  • Iterate over all available IDs.

It should be noted more is possible, there's a pretty web UI for example, but I'm simplifying. Do your own homework :)

With those primitives you can allow a client-library to upload a file once, then in the background a bunch of dumb servers can decide amongst themselves "Hey I have data with ID:33333 - Do you?". If nobody else does they can upload a second copy.

In short this kind of system allows the replication to be decoupled from the storage. The obvious risk is obvious though: if you upload a file the chunks might live on a host that dies 20 minutes later, just before the content was replicated. That risk is minimal, but valid.

There is also the risk that sudden rashes of uploads leave the system consuming all the internal-bandwith constantly comparing chunk-IDs, trying to see if data is replaced that has been copied numerous times in the past, or trying to play "catch-up" if the new-content is larger than the replica-bandwidth. I guess it should possible to detect those conditions, but they're things to be concerned about.

Anyway the biggest downside with camlistore is documentation about rebalancing, replication, or anything other than simple single-server setups. Some people have blogged about it, and I got it working between two nodes, but I didn't feel confident it was as robust as I wanted it to be.

I have a strong belief that Camlistore will become a project of joy and wonder, but it isn't quite there yet. I certainly don't want to stop watching it :)

On to the more personal .. I'm all about the object storage these days. Right now most of my objects are packed in a collection of boxes. On the 6th of next month a shipping container will come pick them up and take them to Finland.

For pretty much 20 days in a row we've been taking things to the skip, or the local charity-shops. I expect that by the time we've relocated the amount of possesions we'll maintain will be at least a fifth of our current levels.

We're working on the general rule of thumb: "If it is possible to replace an item we will not take it". That means chess-sets, mirrors, etc, will not be carried. DVDs, for example, have been slashed brutally such that we're only transferring 40 out of a starting collection of 500+.

Only personal, one-off, unique, or "significant" items will be transported. This includes things like personal photographs, family items, and similar. Clothes? Well I need to take one jacket, but more can be bought. The only place I put my foot down was books. Yes I'm a kindle-user these days, but I spent many years tracking down some rare volumes, and though it would be possible to repeat that effort I just don't want to.

I've also decided that I'm carrying my complete toolbox. Some of the tools I took with me when I left home at 18 have stayed with me for the past 20+ years. I don't need this specific crowbar, or axe, but I'm damned if I'm going to lose them now. So they stay. Object storage - some objects are more important than they should be!

June 21, 2015 12:00 AM

June 19, 2015

Andy Smith

F11 and F12 over serial

I always seem to forget this one.

To pass F11 or F12 over a serial connection (either real serial or Serial-over-LAN IPMI), it’s Escape followed by ! (Shift+1) or @ (Shift+') respectively.

Note that on a US keyboard ! and @ would be next to each other above the 1 and 2 keys so that would make some vague kind of sense as alternatives to F11 and F12. But it’s literally the @ that matters and since I’m using a UK keyboard then it is Shift+'.

(╯°□°)╯︵ ┻━┻)

by Andy at June 19, 2015 08:39 PM

Fun with Supermicro motherboard serial headers

or, “LOL, standards”

TL;DR: Most motherboards have a serial header in an IDC-10 (5×2 pins) arrangement with the pins as a row of even numbered pins (2,4,6,8,X) followed by a row of odd numbered pins (1,3,5,7,9). Supermicro ones appear to have the pins in sequential order (6,7,8,9,X and then 1,2,3,4,5). As a result a standard IDC-10 to DB-9 cable will not work and you’ll need to either hack one about or buy the Supermicro one.

Are we sitting comfortably?

I bought a Supermicro motherboard. It doesn’t have a serial port exposed at the back. I like to use serial ports for a serial console even though I am aware that IPMI exists. IPMI on this board works okay but I like knowing I can always get to the “real” serial port as well.

The motherboard has a COM1 serial header, and I wasn’t using the PCI expansion slot on the back of the chassis, so I decided to put a serial port there. I bought a typical IDC-10 / DB-9 cable and plate:

IDC-10 to DB-9

Didn’t work. Serial-over-LAN (IPMI) worked alright. On COM1 I would get either nothing or a run of garbage characters from time to time. I wasted a good number of hours messing with BIOS settings, baud rates, checking if my USB serial adaptor actually worked with another device (of which I only have one in my home), before I decided to sit down and check the pin numbering for both the header and the cable.

Looking at the motherboard manual we see this:

x10sdv board com1 pin layout

And the cable?

IDC-10 to DB-9 pinout

Notice anything amiss?

The cable’s pins go in a row of odd numbers and then a row of even numbers:

2 4 6 8 X
1 3 5 7 9
    -

The X is the missing pin (serial uses 9 pins) and the - indicates where the notch for the connector would be: next to pin 5 in this case.

The header’s pins go in sequential order:

6 7 8 9 X
1 2 3 4 5
    -

As a result all but pin 1 are incorrect.

You actually need a Supermicro cable for this. CBL-0010L is the part number in my case. CBL-0010LP would be the low profile version. Good luck finding it mentioned on Supermicro’s site, but your favourite reseller will probably know of it. As it was I found one on Ebay for £1.58+VAT, and it works now.

After knowing what to search for I also found someone else having a similar issue with a Supermicro board.

You could of course instead hack any existing cable’s pins about or fit an adaptor in between (as the person in the above link did).

Thanks Supermicro. Thupermicro.

by Andy at June 19, 2015 04:42 PM

June 13, 2015

Steve Kemp

I'm still moving, but ..

Previously I'd mentioned that we were moving from Edinburgh to Newcastle, such that my wife could accept a position in a training-program, and become a more specialized (medical) doctor.

Now the inevitable update: We're still moving, but we're no longer moving to Newcastle, instead we're moving to Helsinki, Finland.

Me? I care very little about where I end up. I love Edinburgh, I always have, and I never expected to leave here, but once the decision was made that we needed to be elsewhere the actual destination does/didn't matter too much to me.

Sure Newcastle is the home of Newcastle Brown Ale, and has the kind of proper-Northern accents I both love and miss but Finland has Leipäjuusto, Saunas, and lovely people.

Given the alternative - My wife moves to Finland, and I do not - Moving to Helsinki is a no-brainer.

I'm working on the assumption that I can keep my job and work more-remotely. If that turns out not to be the case that'll be a real shame given the way the past two years have worked out.

So .. 60 days or so left in the UK. Fun.

June 13, 2015 12:00 AM