Over the last year and a half, many of us have spent more time than we’d like in front of our computers. Many meetings have happened that way, as well as listening to talks and lectures, or giving them. Our computers’ sound systems have therefore been likely used much more heavily than before, and in different ways. I’ve always had an amp and a pair … Continue reading Linux Echo Canceller
It is a good practice with encryption keys to have these expire regularly (two years is a good place to start). This ensures that if the secret key material is lost or misplaced at any point, there is a safety mechanism that ensures the keys are no longer valid after a certain point. This does not introduce a need to create new keys, but simply … Continue reading Regular GnuPG Key Maintenance
rsync is a lovely tool. Among other things, it can easily synchronise a local folder with a remote one, without needing any additional software on the remote server (as long as you can ssh to it). Of course, it will only actually transfer those files that have changed (or are missing at the receiving end), so it’s as efficient as it could be. However, there … Continue reading Synchronising with a remote folder using a USB drive
A few months ago I finally took the plunge and moved all the data on our home network to ZFS. I have been meaning to write about this for some time, and in a recent weekly meeting with my department’s systems engineer I realised it’s way overdue. So here follows a brief introduction to the use of ZFS for data storage on Ubuntu. Just to … Continue reading A Practical Introduction to ZFS on Ubuntu 18.04 LTS
Today’s tech post is a bit of a note to self. All the information here is available elsewhere on the internet, notably in this post by Elliot Cooper. However, a concise version for my own reference is useful. Perhaps it will also be of use to someone else. Problem description I want to share a folder (/opt/share) on my workstation (server.domain) with co-workers, so they … Continue reading Sharing a folder with other authenticated users over a network in Ubuntu 18.04 LTS
[Note 9-Apr-2020: Since writing this post I migrated my data HDDs to ZFS; I write about ZFS, and on how to cache on SSD, in a more recent post. The OS remains on SSD using LVM.] [Updated 7-Nov-2019: clarified need for thin-provisioning-tools package.] [Updated 30-Aug-2019: added instructions for setting caching mode to writeback.] For the last several years I have been using a combination of … Continue reading Using a SSD to cache data volume on Ubuntu 18.04 LTS
[Edited 2019-08-01: changed Debian release to ‘stretch’] This blog post has been a long time coming. For many years I have used the Torque/PBS job scheduler on machines that I administer or am otherwise responsible for. My blog post on setting up Torque on Ubuntu topped this site’s most-visited pages by a wide margin. I’m also a creature of habit, avoiding changes when there is … Continue reading Installing (Son of) Grid Engine on Ubuntu 18.04 LTS
[Edited 16-May-2019: Added autoconnect option.] I recently started using a pair of Bluetooth headphones with my computer, and initially had a problem with the connection. Specifically, it was pairing properly, but defaulted to the HSP/HFP headset profile (which is suitable for making calls) rather than the A2DP profile (which is higher quality and suitable for media playback). To make matters worse, when I tried to … Continue reading Fixing Bluetooth Headset Playback Profile on Ubuntu 18.04 LTS
A few years ago I wrote a small Android app to facilitate in-phone sharing of photos. The idea was to replicate the final part of the workflow I already had on my PC for sharing photos on my blog: scaling the image down to a reasonable size, adding a border with a photo identifier and copyright information, and removing unnecessary (and privacy-compromising) metadata. You know, … Continue reading Safer Sharing of Photos
[Updated 6-Jul-2020: added details on magic SysRq key sequences.] [Updated 21-Aug-2018: documented what happens with single force.] This is more of a note to self, but perhaps it will be useful to others who find themselves in the same situation. Occasionally I need to reboot a remote server, typically following an upgrade to the kernel or some other low-level package. Now this usually goes without … Continue reading Forced Reboot on Ubuntu 16.04 LTS or later
Came across this text, copied from my console a long time ago, that’s just been sitting there gathering virtual dust. I thought it was rather funny, having to write a very explicit phrase to allow me to continue, rather than just the usual “press Y”. Gotta love the sense of humour of these programmers. Still, it did allow me to continue, as long as I … Continue reading Force
Today’s blog post is a bit of a note to self. As usual, I had solved this problem once before, but had to repeat a fair bit of work to solve it again on another box. So I thought I should really write it up, for future reference. Over the last several weeks I have been working through some long-awaited upgrades to my home PC. … Continue reading Using a Microsoft Bluetooth Mouse on Ubuntu 16.04 LTS
Muddy Boots 