Learning Devuan GNU/Linux - User, Group, Network & Boot

#Introduction

A healthy Linux system needs three operational foundations: well-organized users and groups, a network that's connected, and a boot that's predictable. Episode 7 covers all three in the Devuan context — from creating users with adduser, granting sudo rights, configuring networking with ifupdown, to understanding the boot journey from GRUB to fstab.

These three topics fuel all the episodes ahead. The firewall in episode 13 needs a correct network, hardening in episode 14 needs the right users, and maintenance in episode 16 needs an understanding of boot and fstab. Let's build that foundation now.

#Users and Groups

#Creating Users and Granting Sudo Rights

On Devuan, new users are created with adduser. To grant administrative rights, add the user to the sudo group — because Devuan follows the Debian convention — then manage passwords with passwd:

sudo adduser budi
sudo usermod -aG sudo budi

usermod -aG sudo budi adds budi to the sudo group without removing other groups, thanks to the -a option. After this, budi can use sudo with his own password. Check group membership anytime with groups budi.

#Access Rights and su

To temporarily assume the root identity, use su:

su - budi
sudo -i

su - budi opens a login session as budi, while sudo -i opens a root shell. A security rule of thumb: avoid logging in directly as root; always use a regular user plus sudo, as we'll reinforce in episode 14.

#Networking with ifupdown

#Static and DHCP Configuration

Devuan's default uses ifupdown, configured through /etc/network/interfaces. The format is clear and free of systemd:

auto eth0
iface eth0 inet dhcp
 
auto eth1
iface eth1 inet static
    address 192.168.1.10
    netmask 255.255.255.0
    gateway 192.168.1.1
    dns-nameservers 1.1.1.1 8.8.8.8

To apply changes without rebooting:

sudo ifdown eth0 && sudo ifup eth0
sudo ip addr show eth0

The command ip addr show eth0 shows the current IP configuration. If you're using DHCP, make sure the dhcpcd or dhclient service is running — on Devuan it's generally managed through the networking service.

#Alternative: NetworkManager for Desktop

On desktop installations, NetworkManager is often the network manager so Wi-Fi connections are easy to set up:

sudo service NetworkManager status
nmcli device status

nmcli device status shows devices and their connection states. NetworkManager and ifupdown must not manage the same interface at the same time to avoid conflicts.

#The Boot Process

#From GRUB to Init

Devuan's boot journey: GRUB loads the Linux kernel, the kernel executes the initramfs to prepare the filesystem and devices, then hands control to init (PID 1), which we covered in episode 5. init then processes the default runlevel from /etc/inittab.

Check the boot parameters and active kernel:

uname -r
cat /proc/cmdline

cat /proc/cmdline shows the arguments passed by GRUB to the kernel — for example quiet or root= parameters. This is your first window when troubleshooting boot.

#fstab: Mounting Filesystems

Once init is ready, the system mounts filesystems according to /etc/fstab. Each line contains the device, mount point, filesystem type, options, dump, and fsck order:

/dev/sda1 / ext4 defaults 0 1
/dev/sda2 /home ext4 defaults 0 2
/dev/sda3 swap swap defaults 0 0

Check that all mount points are correct:

mount -a
df -h

mount -a mounts all filesystems in fstab that aren't already active. An error in fstab can prevent boot, so test changes with mount -a before rebooting.

#Conclusion

Episode 7 completed Devuan's operational foundation: creating users and groups with adduser and usermod, granting sudo rights, configuring networking with ifupdown and the NetworkManager alternative, and understanding the boot process from GRUB, kernel, initramfs, init, to mounting filesystems through fstab.

Key takeaways:

• adduser creates users; usermod -aG sudo grants administrative rights.
• su and sudo -i for switching identity safely.
• ifupdown uses /etc/network/interfaces for network configuration.
• NetworkManager is suited for desktops and Wi-Fi.
• Boot runs: GRUB, kernel, initramfs, init, runlevel.
• fstab determines which filesystems are mounted at boot.

In the next episode, we'll cover desktop environment and display — choosing XFCE, KDE, MATE, or GNOME on Devuan, configuring Xorg and LightDM, and the role of elogind as the non-systemd session manager.