- 21 July 2023
Running a backup MX host is a good idea if you want to ensure that e-mails are not lost if your primary MX host is down. With Postfix, this is easy to set up on a Debian or Ubuntu system as both are shipped with Postfix.
Mail servers that are misconfigured can be used to send spam. Therefore, you should closely monitor your mail server and make sure that it is not misused by spammers. In case of any doubt, you should shut down your mail server immediately.
- 30 April 2023
Installing Linux on a physical or virtual machine can be fun for a couple of time, but configuring a system can be combursome after a couple of times. Red Hat developed Kickstart to install and configure machines via the network, but also as part of an ISO file that can used in a virtual CD-ROM drive or on a bootable USB-drive.
The following steps are required to create a bootable ISO file with a kickstart file and when the ISO file is booted, the kickstart file is used to install and configure the system. Creating a bootable ISO file is not a difficult task, but it is a manual procedure. The following steps are required to create a bootable ISO file with a kickstart file.
- 21 August 2022
Vagrant is a tool for building and managing virtual machines locally with just a few commands and a single file. It is a good way to get started with infrastructure-as-code on your local machine. Vagrant is also shipped with Fedora to make it easier to install and use as it uses libvirt to manage the virtual machines running on Linux with kernel virtualization to provide virtual hardware. This works well until you also want to install Terraform from the HashiCorp repository and later you upgrade Vagrant to a newer version with a regular package update.
In the example above Vagrant fails to find libvirt to connect to KVM and manage the virtual machine. Multiple providers are available for Vagrant to use, but the one that is used is not the one that is installed on the machine or can be used. This is a known issue with Vagrant on Linux and does not use the system Ruby environment with the lirbary for libvirt. Downgrading to the version of Vagrant that is shipped with Fedora will fix this issue.
- 18 June 2019
HashiCorp Vagrant normally selects the right hypervisor, but the version shipped with Fedora 30 prefers to run within the QEMU user session of the hypervisor. A .Vagrantfile it would match the default behavior which doesn’t require any system privileges is shown below.
In some cases a virtual machine needs to run on QEMU system level and that can be done by changing the domain.uri from “qemu:///session” to “qemu:///system”. Vagrant now creates the virtual machine at the system level of the hypervisor and isn’t depending on any user environment to run.