VRRP (Virtual Router Redundancy Protocol) is commonly used for providing first-hop IPv4 or IPv6 router (“default gateway”) redundancy for network-attached devices. Some network appliances like wireless LAN controllers use it to provide a virtual IP that can always be used for reaching the active member in the device cluster. VRRP can also be used on […]
These notes have been tested with Proxmox Virtual Environment (PVE) 8.2.4, Debian 12 and cloud-init 22.4.2 (from Debian 12 packaging). First create a virtual machine and install Debian Linux on it normally, with all the additional tools and updates as required. I usually use the netinstall CD image from Debian. After completing the installation, for […]
I often need a Linux virtual machine for testing specific things. Debian Linux is my choice of Linux distribution, and I have wondered how much space does each installed package take in it, to possibly optimize the size of the VM if needed. I installed two VMs: The results after “sudo apt clean“: Installation Disk […]
I have been using VDR – the Video Disk Recorder – on my own Linux host for over 20 years. It has been the primary way of consuming broadcast TV content in our household since 2004. Until now my VDR setup has only been capable of using DVB-C channels in SD, due to the non-HD-capable […]
When doing a major version upgrade on Debian Linux with PostgreSQL server installed (using Debian-provided packages), this always catches me: After the upgrade there will be two different PostgreSQL instances running, it won’t do an in-place upgrade for the database automatically. In order to get the existing database running on the newer PostgreSQL version, this […]
Let’s go right away to the question: How do I enter commands on two devices at the same time? One of the possible answers is: With tmux. My usual workflow to connect to the end devices is from a Linux host that has tmux installed. The situation can look for example like this: Before being […]
Logrotate runs daily by default on Debian Linux. It is scheduled to run at 00:00:00 with systemd: markku@logtest:~$ systemctl list-timers NEXT LEFT LAST PASSED UNIT ACTIVATES Mon 2023-11-20 00:00:00 EET 2h 20min left Sun 2023-11-19 00:00:17 EET 21h ago logrotate.timer logrotate.service … When you want logrotate to rotate files hourly, you need two changes: For […]
Debian has been my primary Linux distribution of choice since 2003. That’s twenty years! How time flies! I haven’t ever worked as full-time server administrator but running and operating various kinds of systems have always been part of my skills, and it has made it possible for me to leverage wide range of tooling required […]
Even though I’ve used Python programming language on-and-off since about year 2000, I only started paying more attention to specific Python versions around 2016 when I gradually started using Python more seriously in devops. When dealing with different runtime environments it is crucial to know which features are available in which Python versions. This page […]
A long time ago I discovered screen. It made it possible to start applications in Linux and then disconnecting the SSH session, without stopping the applications. It was magic: otherwise the the applications just terminated if the SSH connection was lost. Then I heard about tmux. It was like screen on steroids! I could split […]