Linkat 22.04 LTS install¶

OS Installation¶

To transform it into Linkat, the official instructions have been executed. On a desktop with Ubuntu 22.04 LTS installed:

$ wget http://download-linkat.xtec.cat/distribution/linkat-edu-22.04/main/linkat-install_22.04-3_all.deb
$ sudo dpkg -i linkat-install_22.04-3_all.deb

The Linkat installer application opens.
A terminal will open and ask for the administrator password.
Select the lightdm (Mate) window manager.
Restart the computer when finished.

Isard (admin or manager roles)¶

Modify desktop XML

<driver name="qemu" type="qcow2" cache="unsafe" discard="unmap"/>

Configuration¶

Service status

apparmor: active
ufw firewall: active
sshd: not installed

Terminal¶

Basic commands

$ sudo apt update
$ sudo apt upgrade -y
$ sudo apt install vim gedit vlc net-tools htop curl wget spice-vdagent qemu-guest-agent

Modify fstab

$ sudo vim /etc/fstab
for every "ext4" storage, define "noatime,discard"

UUID=xxxxx-xxxxx-xxxxxx /               ext4    defaults,noatime,discard,errors=remount-ro 0       1

Free up system space

$ cd /
$ sudo fstrim -a -v

Reduce swap memory

$ sudo sysctl vm.swappiness=1

Reduce log storage

$ sudo vim /etc/systemd/journald.conf
SystemMaxUse=20M
SystemKeepFree=4G

Disable automatic updates and new update notifications

$ sudo apt purge update-manager update-notifier*
$ sudo vim /etc/apt/apt.conf.d/50unattended-upgrades
Unattended-Upgrade::DevRelease "false";
$ sudo vim /etc/update-manager/release-upgrades
Prompt=never
$ sudo snap refresh --hold 
$ sudo snap set system refresh.retain=3

Enable user auto-login

$ sudo vim /usr/share/lightdm/lightdm.conf.d/50-arctica-greeter.conf
# add next line to the end of file
autologin-user=isard

Enable RDP access

$ sudo apt install xrdp
$ sudo systemctl enable xrdp
$ sudo systemctl restart xrdp

$ sudo vim /etc/X11/Xsession.d/80mate-environment
# add next line before 'fi' closes, last line inside conditional
unset DBUS_SESSION_BUS_ADDRESS

Screen resizing

$ sudo echo 'ACTION=="change",KERNEL=="card0", SUBSYSTEM=="drm", RUN+="/usr/local/bin/x-resize"' > /etc/udev/rules.d/50-x-resize.rules
$ sudo vim /usr/local/bin/x-resize
#! /bin/sh
PATH=/usr/bin
export DISPLAY=:0.0
xrandr --output "$(xrandr | awk '/ connected/{print $1; exit; }')" --auto

$ sudo chmod 744 /usr/local/bin/x-resize

Remove unused kernel images

$ sudo dpkg --get-selections | grep linux-image
$ sudo uname -a
$ sudo apt-get purge linux-image-5.19.0-32-generic
$ sudo apt-get purge linux-image-generic-hwe-22.04

System Settings¶

Administration - Software & Updates

Hardware - Power Management

Look and Feel - Screensaver

Customization¶

Terminal¶

Change login wallpaper

$ sudo vim /usr/share/glib-2.0/schemas/30_ubuntu-mate.gschema.override
background='/path/to/wallpaper'
$ sudo glib-compile-schemas /usr/share/glib-2.0/schemas/

System Settings¶

Personal - About Me