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Links December 2020

Business Insider has an informative article about the way that Google users can get locked out with no apparent reason and no recourse [1]. Something to share with clients when they consider putting everything in “the cloud”.

Vice has an interestoing article about people jailbreaking used Teslas after Tesla has stolen software licenses that were […]

ZFS 2.0.0 Released

Version 2.0 of ZFS has been released, it’s now known as OpenZFS and has a unified release for Linux and BSD which is nice.

One new feature is persistent L2ARC (which means that when you use SSD or NVMe to cache hard drives that cache will remain after a reboot) is an obvious feature that […]

KDE Icons Disappearing in Debian/Unstable

One of my workstations is running Debian/Unstable with KDE and SDDM on an AMD Radeon R7 260X video card. Recently it stopped displaying things correctly after a reboot, all the icons failed to display as well as many of the Qt controls. When I ran a KDE application from the command line I got the […]

Links November 2020

KDE has a long term problem of excessive CPU time used by the screen locker [1]. Part of it is due to software GL emulation, and part of it is due to the screen locker doing things like flashing the cursor when nothing else is happening. One of my systems has an NVidia card and […]

Video Decoding

I’ve had a saga of getting 4K monitors to work well. My latest issue has been video playing, the dreaded mplayer error about the system being too slow. My previous post about 4K was about using DisplayPort to get more than 30Hz scan rate at 4K [1]. I now have a nice 60Hz scan rate […]

First Attempt at Gnocchi-Statsd

I’ve been investigating the options for tracking system statistics to diagnose performance problems. The idea is to track all sorts of data about the system (network use, disk IO, CPU, etc) and look for correlations at times of performance problems. DataDog is pretty good for this but expensive, it’s apparently based on or inspired by […]

Bandwidth for Video Conferencing

For the Linux Users of Victoria (LUV) I’ve run video conferences on Jitsi and BBB (see my previous post about BBB vs Jitsi [1]). One issue with video conferences is the bandwidth requirements.

The place I’m hosting my video conference server has a NBN link with allegedly 40Mb/s transmission speed and 100Mb/s reception speed. My […]

Qemu (KVM) and 9P (Virtfs) Mounts

I’ve tried setting up the Qemu (in this case KVM as it uses the Qemu code in question) 9P/Virtfs filesystem for sharing files to a VM. Here is the Qemu documentation for it [1].

VIRTFS=”-virtfs local,path=/vmstore/virtfs,security_model=mapped-xattr,id=zz,writeout=immediate,fmode=0600,dmode=0700,mount_tag=zz” VIRTFS=”-virtfs local,path=/vmstore/virtfs,security_model=passthrough,id=zz,writeout=immediate,mount_tag=zz”

Above are the 2 configuration snippets I tried on the server side. The first uses mapped xattrs […]

Links September 2020

MD5 cracker, find plain text that matches MD5 hash [1].

Debian Quick Image Baker – Debian VM images for various architectures [2].

Insightful article on Scientific American about how dental and orthodontic problems are caused by our modern lifestyle [3].

Cory Doctorow wrote an insightful article for Locus Magazine about Intellectual Property [4]. He makes […]

Burning Lithium Ion Batteries

I had an old Nexus 4 phone that was expanding and decided to test some of the theories about battery combustion.

The first claim that often gets made is that if the plastic seal on the outside of the battery is broken then the battery will catch fire. I tested this by cutting the battery […]