Category Archives: Linux Administration
apt – install the package that contains a specific file
Sometimes a command that you execute complains about a dependency being missing on the system. From the file name in the error message it is often not possible to know exactly which package needs to be installed to resolve the … Continue reading
Increase the size of a LUKS encrypted partition
Even encrypted discs or partitions sometimes need to have their size increased. A LUKS encrypted volume consists of different layers which all need to be resized. To resize an encrypted volume, multiple steps have to be performed to use the additional … Continue reading
Permanently reject a specific email sender address using postfix
Postfix generally accepts all sender addresses. It might be needed in some rare cases to reject one sender addresses for some reason. With postfix, there is the possibility to use the “check_sender_access” to set individual actions per sender address. For the … Continue reading
Verifying SSH configuration with a scan
Managing a number of Linux servers and keeping them secure can be a challenge. Certain tools can make the life of an admin a lot easier. To ensure an ssh daemon complies with a desired security configuration the admin can use a scanner … Continue reading
Debug SSH Connection issue in key exchange
Securing a server means hardening the SSH server settings, but doing so can also cause issues with ssh clients. Finding the cipher or algorithm causing a failled connection can be tricky. Depending on the client used, the error message might be very … Continue reading
Automount a luks encrypted volume on system start
Linux supports encrypted volumes with luks. When a luks encrypted volume is set up during installation to be booted from, the volume is already configured and set up. When an encrypted volume is set up afterwards, the volume remains locked until … Continue reading
Harden SSH server settings
Many Linux Administrators use ssh on a daily basis. Many of the ssh servers are in their default configuration. Not changing the default configuration puts the security of the server at risk. That is why it is important to follow a few … Continue reading
Get vim to paste content without modification
When content is pasted into vim, it tries to automatically detect and re-indent the content. This works most of the time but sometimes it does not, and that can be annoying, but vim would not be so popular if there wasn’t … Continue reading
Change Date and Time format for LinuxMint panel applet
Modern Linux distributions like LinuxMint provide a nice GUI which is highly configurable. There are so many options and possibilities that most users new to it cannot find where things are configured. Finding the right options means taking some time to … Continue reading
