Category: linux
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bash – escaping variables for use within commands
Escaping quotes within variables is always painful in bash (somehow) – e.g. foo”bar and it’s not obvious that you’d need to write e.g. “foo”\””bar” (at least to me). Thankfully a bash built in magical thing can be used to do the escaping for you. In my case, I need to pass a ‘PASSWORD’ variable through…
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asus pn50 and cpufreq/boost
I’ve been using an ASUS PN50 (that’s a mini pc, with an AMD Ryzen 4800u processor – so sort of a laptop without a screen) as my desktop for ages. Increasingly I’ve found it sluggish and I was contemplating replacing it with something newer, and then I discovered why the CPU speed in /proc/cpuinfo was…
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Resizing a VM’s disk within Azure
random notes on disk resizing with an Azure VM
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Don’t forget to defragment /home if you’re using BTRFS
don’t forget to defragment a btrfs filesystem … large (sqlite database like files etc) will fragment and become slow
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btrfs & ext4 – error handling when the hardware fails …
btrfs vs ext4 … how they cope when your computer overheats…
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systemd-resolve (DNS is always to blame)
Random unscientific finding; perhaps systemd-resolve isn’t quite ready for prime time yet?
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faster rsync (ssh cipher choice)
Perhaps the bottleneck isn’t always bandwidth – but does changing ssh cipher make any difference? Using a derivative of : In unscientific tests, it looks like ssh parameters might do something when copying a 4GiB file between two random virtual machines in different data centres, but both in London. SSH Variant Speed -e “ssh” ~45MB/s…
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(re)building varnish modules
Automated rebuilding of varnish modules using docker …
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AWS vs Azure … round 1, fight!
So, for whatever reason, I need to move some virtual machines and things from AWS (EC2, RDS), to an Azure. I have a few years experience with AWS, but until recently I’ve not really used Azure …. Here are some initial notes…… AWS tooling feels more mature (with the ‘stock’ ansible that ships with Ubuntu…
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rsyslog filtering (with loggly)
Filtering rsyslog output being sent to loggly (e.g. from an apache imfile input)