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 […]

restart firewalld after installing tftp *client*

edit: the title of the post is wrong, and I’ll repost it when I’ve got around to crossing all the tees.  There’s a firewalld service called tftp-client;  the fix for machines with a tftp client is thus probably to enable that. This post covers off a number of other topics as well – turned out […]

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 […]