Highlands Festival of Speed 2018

Last weekend I headed to New Zealand and marshalled at the Highlands Festival of Speed. The Highlands Festival of Speed is a weekend packed with some of the best modern classic racing you will see in New Zealand. Featuring the Pre 65 Racing, Mainland Muscle, Formula Libre, South Island Porsche, OSCA, Highlands Modern Classics/Nostalgic Classics and the Highlands Sprint Series. This is a weekend of true blue Kiwi racing starring some of New Zealand’s most well known racing legends. ...

April 11, 2018 · 1 min · 140 words · Sam McLeod

Flash Storage and SSD Failure Rate Update (March 2018)

It was almost 3 years ago that my open source storage project went into production. In that time it’s been running 24/7 serving as highly available solid state storage for hundreds of VMs and several virtualisation clusters across our two main sites. I’m happy to report that the clusters have been operating very successfully since their conception. Since moving away from proprietary ‘black box’ vendor SANs, we haven’t had a single SAN issue, storage outage. ...

March 20, 2018 · 2 min · 326 words · Sam McLeod

Theory of constraints

“A chain is no stronger than its weakest link” Any improvement made anywhere besides the bottleneck is an illusion. Any improvement made after the bottleneck is useless because it will always remain starved waiting for work from the bottleneck. Any improvement made before the bottleneck merely results in more ‘work’ piling up at the bottleneck. Identify the system’s constraint(s) (that which prevents the organisation from obtaining more of the goal in a unit of time) Decide how to exploit the system’s constraint(s) (how to get the most out of the constraint) Subordinate everything else to the above decision (align the whole system or organization to support the decision made above) Elevate the system’s constraint(s) (make other major changes needed to increase the constraint’s capacity) Warning! If in the previous steps a constraint has been broken, go back to step 1, but do not allow inertia to cause a system’s constraint. References The Phoenix Project Wikipedia - Theory of Constraints

January 17, 2018 · 1 min · 159 words · Sam McLeod

Top album picks for 2017

Here are my top album pics for 2017 (in no particular order) Note: This is by no means an exhaustive list, it’s just the top albums that really stood out to me and in all fairness, I’ve thought of several others since so there may be a follow up post (or two). Father John Misty - Pure Comedy As a bonus, a short film was released with the album: From Wikipedia: ...

December 28, 2017 · 4 min · 641 words · Sam McLeod

HP 4951C Protocol Analyser

My good friend Joel Shea received a most unlikely gift this Christmas - A vintage HP 4951 Protocol Analyser. According to the HP Computer Museum: Original Price: $3595 The 4951B was replaced by the 4951C and 4952A in 1986. Both new models handled Async, BSC, SDLC, HDLC, X.25 and SNA protocols. The 4951C also handled DDCMP, while the 4952A did not. The 4952A handled X.21 while the 4951C did not. Both new analysers used a floppy dive (618 KB) for removable media. ...

December 27, 2017 · 1 min · 91 words · Sam McLeod

Talk - Clustered, Distributed File and Volume Storage with GlusterFS

Using GlusterFS to provide volume storage to Kubernetes as a replacement for our existing file and static content hosting. This talk was given at Infracoders on Tuesday 14th November 2017. NOTE: Below link to slides currently broken - will fix soon! (03/08/2019) Click below to view slides (PDF version): Direct download link

November 14, 2017 · 1 min · 52 words · Sam McLeod

Applying syntax in Sublime based on the first file line

In vim, you can add a comment at the top of files to set the syntax, e.g.: # vim: syntax=ruby In SublimeText there are many ways to detect syntax, one interesting approach I’ve recently found useful is to match on the top line in the file. For example, with Puppet there is a file called Puppetfile, it has no extension but it’s really Ruby syntax, so it’s useful to add linting incase you miss something simple like a , and break deployments. ...

October 25, 2017 · 1 min · 162 words · Sam McLeod

Broadcom, Or How I Learned To Start Worrying And Drop The Packet

Earlier this week we started the process to upgrade one of our hypervisor compute clusters when we encountered a rather painful bug with HP’s Broadcom NIC chipsets. We were part way through a routine rolling pool upgrade of our hypervisor (XenServer) cluster when we observed unexpected and intermittent loss of connectivity between several VMs, then entire XenServer hosts. The problems appeared to impact hosts that hadn’t yet upgraded to XenServer 7.2. We now attribute this to a symptom of extreme packet loss between the hosts in the pool and thanks to buggy firmware from Broadcom and HP. ...

October 13, 2017 · 6 min · 1240 words · Sam McLeod

GlusterFS

We’re in the process of shifting from using our custom ‘glue’ for orchestrating Docker deployments to Kubernetes, When we first deployed Docker to replace LXC and our legacy Puppet-heavy application configuration and deployment systems there really wasn’t any existing tool to manage this, thus we rolled our own, mainly a few Ruby scripts combined with a Puppet / Hiera / Mcollective driven workflow. The main objective is to replace our legacy NFS file servers used to host uploads / attachments and static files for our web applications, while NFS(v4) performance is adequate, it is a clear single point of failure and of course, there are the age old stale mount problems should network interruptions occur. ...

September 25, 2017 · 6 min · 1106 words · Sam McLeod

Return Of The RSS

Of all the tools for reading news and subscribing to software releases, I still find RSS the most useful. I use Feedly to manage my rss subscriptions and keep all my devices in sync, but instead of using the Feedly’s own client, I use an app called Reeder as the client / reader itself. Link: My Feedly RSS Feed Feedly RSS feed subscription management Features: Keyword alerts. Browser plugins to subscribe to (current) url. Notation and highlighting support (a bit like Evernote). Search and filtering across large numbers of feeds / content. IFTTT, Zapier, Buffer and Hootsuite integration. Built in save / share functionality (that I only use when I’m on the website). Backup feeds to Dropbox. Very fast, regardless of the fact that I’m in Australia - which often impacts the performance of apps / sites that tend to be hosted on AWS in the US as the latency is so high. Article de-duplication is currently being developed I believe, so I’m looking forward to that! Easy manual import, export and backup (no vendor lock-in is important to me). Public sharing of your Feedly feeds (we’re getting very meta here!). Reeder A (really) beautiful and fast iOS / macOS client ...

September 22, 2017 · 2 min · 283 words · Sam McLeod