Debian on Kohanyi News

Linux rc.local on Modern Systemd (Debian 13)

Wed, 19 Aug 2026 10:30:00 +0000

If you miss the old /etc/rc.local from the SysV days – it still works on modern systemd systems. You just need to enable it manually.

Create the systemd service unit

sudo nano /etc/systemd/system/rc-local.service

Paste this:

[Unit]
Description=/etc/rc.local
ConditionPathExists=/etc/rc.local

[Service]
Type=forking
ExecStart=/etc/rc.local start
TimeoutSec=0
StandardOutput=tty
RemainAfterExit=yes
SysVStartPriority=99

[Install]
WantedBy=multi-user.target

Create rc.local

sudo nano /etc/rc.local

Paste this:

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

exit 0

Enable and test

sudo chmod +x /etc/rc.local
sudo systemctl enable rc-local
sudo systemctl start rc-local.service
sudo systemctl status rc-local.service

Notes

Any commands placed before exit 0 will run at the end of every multiuser boot. Useful for old habits, kernel tweaks, or hardware init that doesn’t have a proper systemd service yet.
This works on Debian 13 Trixie. Also works on Ubuntu 18.04+, RHEL 7+, and most modern distros.

Setting Up Serial Console Access on a Linux Server

Wed, 19 Aug 2026 10:00:00 +0000

If your server has a virtual serial port – like HP iLO, Dell iDRAC, or any BMC that exposes a serial console over SSH – this gets you keyboard-in-the-face access before the network stack is even up.

Useful for debugging boot issues, GRUB recovery, or just not having to walk to the machine room.

Find your serial port

sudo dmesg | grep tty

Look for something like ttyS0, ttyS1, etc. On many systems:

Debian with Encrypted Root and Automatic Unlock via Tang + Clevis

Wed, 19 Aug 2026 09:30:00 +0000

A recipe for installing Debian with a LUKS-encrypted root filesystem and configuring it to unlock automatically at boot using Tang and Clevis (Network-Bound Disk Encryption).

Disclaimer: This process will nuke all data on the drives you target. Back up anything you want to keep before you start.

This works on plain ext4 on LUKS (Part 1 below) and on ZFS on LUKS equally – Clevis binds to the LUKS layer regardless of what is on top.

Debian 13 with Encrypted ZFS Root (ZFS on LUKS)

Wed, 19 Aug 2026 09:00:00 +0000

A step-by-step recipe for installing Debian 13 (Trixie) with a fully encrypted root filesystem using ZFS on top of LUKS.

Disclaimer: This process will nuke all data on the drives you target. Back up anything you want to keep before you start.

This gives you the integrity and snapshot features of ZFS, with the whole disk encrypted at rest. I use this on my home servers and VPS instances.

Prerequisites

Debian 13 Live ISO (the standard live image, not the netinst)
Two disks for a mirror, or one disk if you are starting small
UEFI boot (recommended for modern systems)

Why not just ZFS native encryption?

ZFS native encryption (zencrypt) exists and works. But LUKS gives you a battle-tested crypto layer that GRUB, initramfs, and every Linux tool understand natively. Combined with ZFS on top, you get the best of both worlds.