kvm: libvirt-guests and machined

Two main things covered off in this post: Getting libvirt-guests to work correctly, and machined/machinectl libvirt-guests This is configured via /etc/sysconfig/libvirt-guests and there’s a systemd service to enable: libvirt-guests.service Enabling it allows you to configure how guests start and stop with more flexibility. Some features libvirt-guests provides: On host shutdown, suspend the guests or shut […]

puppetising kvm on centos7

Yak shaving I found out about a bunch of stuff today, including the now 19-year-old term yak shaving. Clearer examples out there such as here, here and here. I was trying to roll creation of KVM virtual machines into Puppet (that is, bring my existing use of KVM at home under management) and in unpicking […]

AWOL Linux LVM volume group and physical volume

TL;DR Looks like there maybe a bug in lvm2-2.02.180-10.el7_6.3. Will raise a ticket for it with Centos. Update 2019-02-23 Ticket raised with Centos. Having tried to reproduce it on another machine, it takes more than just upgrading the package – as one would expect. No idea what the other variables might be. Update 2019-04-22 I […]

java – troubleshooting SSL/TLS truststores

Troubleshooting TLS issues involving a Java app can be difficult if the division of responsibility means that responsibility for the certs and truststores is not vested in a team with any Java skill.  This post is aimed at someone, like me, in that situation. SSLPoke Atlassian (JIRA/Confluence/Bitbucket) provide a simple program that does about as […]

ELK 6.5 stack on Raspberry Pi / Centos7

Summary The goal was to create a syslog server on a Raspberry Pi, so I can ship all my logs to a low power machine that’ll be on all the time. tl;dr – a bit optimistic. The limited memory would probably require Elasticsearch (ES) and Logstash (LS) on different machines. I think Logstash really wants […]

cleaning signatures off disks

Tripped over an issue recycling a disk using LVM WARNING: dos signature detected on /dev/disk/by-id/ata-TOSHIBA_MK6459GSX_X9QCF7BGS at offset 510. Wipe it? [y/n]: [n] Aborted wiping of dos. 1 existing signature left on the device. This came from (failed) volume group creation within a puppet run. hat-tip. There’s a tool called wipefs which fixes this.  I’d like […]

puppet agent, centos 7 and raspberry pi

There’s no armv7l packages of the puppet agent, so I need to run it from source. The docs for doing this date back to 3.8. Also helped by this post by Brandon Martin. I’ll be looking to run the following client version to match my PE install. # puppet –version 4.10.12 Pre-requisites Applicable requirements come […]

getting started with centos7 on raspberry pi 3 b+

My notes on getting these bootstrapped. Get image onto SD card Example is for centos 7.6, released 2018-10 (1810) centos docs img=CentOS-Userland-7-armv7hl-RaspberryPI-Minimal-1810-sda.raw unxz ${img}.xz sudo dd if=./${img} of=/dev/mmcblk1 status=progress bs=8192 ; sudo sync At time of writing, this was a Centos 7.6 image, and by default had a 1.4gb ext4 root partition with 421mb free, […]