Tag Archives: debian

Configuring Linux on a ThinkPad T420s Laptop

Reply

ThinkPad T420s laptops, despite their age, remain reliable for web browsing, word processing, and various other tasks. Linux can breathe new life into such dated computers, allowing them to perform efficiently.

I configured one of these laptops for my son, and he is now able to do his homework using it. With proper configuration, ThinkPad laptops can achieve optimal performance and power management. This article provides a guide to configuring X11/Xorg, kernel parameters, firmware, fan control, and power management settings to optimize the ThinkPad t420s for modern use.

Some instructions in this article are specific to Debian/Ubuntu-based distributions, but they can easily be adapted to other distributions such as Red Hat, Fedora, Arch Linux, Gentoo, and others.

X11/Xorg

To ensure proper functionality of Intel graphics and avoid issues such as black screens after waking from sleep, use the Intel driver instead of modesetting.

Create the configuration file /etc/X11/xorg.conf.d/30-intel.conf:

Section "Device"
  Identifier "Intel Graphics"
  Driver "intel"

  Option "Backlight" "intel_backlight"
EndSectionCode language: plaintext (plaintext)

Ensure the intel driver is installed:

sudo apt-get install xserver-xorg-video-intelCode language: plaintext (plaintext)

IMPORTANT: Ensure that the integrated graphics are set as the default video card in the ThinkPad BIOS.

Kernel parameters

To ensure backlight control is working (increasing and decreasing brightness), add the following kernel parameter: acpi_backlight=native

On a Debian/Ubuntu based distribution, this can be appended to the kernel command line in the bootloader configuration, typically in /etc/default/grub (for GRUB users):

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=native"Code language: plaintext (plaintext)

(If you experience suspend/resume issues, a black screen, or system freezes, try adding the noapic kernel parameter.)

After modifying this file, update GRUB with:

sudo update-grubCode language: plaintext (plaintext)

Fan control

Without software to control the fan, it may run at maximum speed. To enable fan control, create the file /etc/modprobe.d/thinkpad_acpi.conf:

options thinkpad_acpi fan_control=1Code language: plaintext (plaintext)

After that, install zcfan. On a Debian/Ubuntu based distribution:

sudo apt-get install lm-sensors zcfanCode language: plaintext (plaintext)

(An alternative to zcfan: thinkfan)

Packages

Ensure that the required firmware for Atheros and Realtek network devices is installed, along with the tp-smapi-dkms package to enable access to ThinkPad-specific hardware features via the TP-SMAPI kernel modules. On Debian- and Ubuntu-based distributions, install the following packages:

sudo apt install firmware-atheros firmware-realtek tp-smapi-dkmsCode language: plaintext (plaintext)

It is also recommended to install essential packages for hardware encoding and decoding, including intel-microcode for the latest processor updates, which improve system stability and performance:

sudo apt-get install intel-microcode intel-media-va-driver-non-free i965-va-driverCode language: plaintext (plaintext)

TLP

TLP is a power management tool that optimizes battery life. Install and configure it as follows:

sudo apt install tlpCode language: plaintext (plaintext)

Create the configuration file /etc/tlp.d/00-base.conf:

DEVICES_TO_DISABLE_ON_BAT="bluetooth wwan"
DEVICES_TO_ENABLE_ON_STARTUP="wifi"
DEVICES_TO_DISABLE_ON_LAN_CONNECT="wifi wwan"

TLP_DEFAULT_MODE=BAT

CPU_SCALING_GOVERNOR_ON_AC=performance
CPU_SCALING_GOVERNOR_ON_BAT=schedutil

# PCIe Active State Power Management (ASPM):
PCIE_ASPM_ON_AC=performance

# Set Intel CPU performance: 0..100 (%). Limit the
# max/min to control the power dissipation of the CPU.
# Values are stated as a percentage of the available
# performance.
CPU_MIN_PERF_ON_AC=70
CPU_MAX_PERF_ON_AC=100

# [default] performance powersave powersupersave. on=disable
RUNTIME_PM_ON_AC=on
RUNTIME_PM_ON_BAT=powersupersaveCode language: Python (python)

Conclusion

The ThinkPad T420s, though older models, remain reliable machines for everyday tasks. With the right configuration, these laptops can be revitalized, making them well-suited for modern use.

Ansible: Installing and configuring Gitolite using Ansible for secure Git repository management

Reply

EDIT: The latest version of the code is available in the repository:
jamescherti/ansible-role-gitolite

Gitolite provides a way to manage Git repositories, control access to those repositories, and maintain a central configuration using simple configuration files and SSH keys.

Automating Gitolite Installation with Ansible

The Ansible tasks outlined in this article are designed to simplify the installation and configuration of Gitolite on your server. These tasks can automatically handle the entire setup process, including prerequisites like installing necessary packages and configuring system users and groups.

This automation significantly reduces the risk of human error and ensures a consistent setup across different environments.

The Ansible tasks:

---
# Automating Gitolite Installation with Ansible
# License: MIT
# Author: James Cherti
# URL: https://www.jamescherti.com/ansible-install-gitolite-linux/

- name: Install Gitolite
  block:
    - name: Check if the Operating System is supported
      fail:
        msg: "Operating System family is not supported: {{ ansible_os_family }}"
      when: ansible_os_family not in ["Debian", "RedHat"]

    - name: Install Gitolite on Debian-based Systems
      apt:
        name: gitolite3
      when: ansible_os_family == "Debian"

    - name: Install Gitolite on RedHat-based Systems
      yum: name=gitolite3
      when: ansible_os_family == "RedHat"

    - name: Create Gitolite system group
      group:
        name: "{{ gitolite_group }}"
        system: true

    - name: Create Gitolite system user
      user:
        name: "{{ gitolite_user }}"
        group: "{{ gitolite_group }}"
        home: "{{ gitolite_home }}"
        shell: "{{ gitolite_shell }}"
        create_home: true
        system: true

    - name: Ensure Gitolite home directory exists with proper permissions
      file:
        state: directory
        path: "{{ gitolite_home }}"
        owner: "{{ gitolite_user }}"
        group: "{{ gitolite_group }}"
        mode: 0700

- name: Configure Gitolite SSH key
  block:
    - name: Generate Gitolite SSH key pair if it does not exist
      become: true
      become_user: "{{ gitolite_user }}"
      command: ssh-keygen -t rsa -b 4096 -f {{ gitolite_ssh_key_path | quote }} -N ""
      args:
        creates: "{{ gitolite_ssh_key_path }}"

    - name: Set permissions for the Gitolite .ssh directory
      file:
        path: "{{ gitolite_ssh_directory }}"
        owner: "{{ gitolite_user }}"
        group: "{{ gitolite_user }}"
        mode: 0700

    - name: Set permissions for the SSH public key
      file:
        path: "{{ gitolite_ssh_key_path }}.pub"
        owner: "{{ gitolite_user }}"
        group: "{{ gitolite_user }}"
        mode: 0644

    - name: Set permissions for the SSH private key
      file:
        path: "{{ gitolite_ssh_key_path }}"
        owner: "{{ gitolite_user }}"
        group: "{{ gitolite_user }}"
        mode: 0600

- name: Setup Gitolite
  block:
    - name: Initialize Gitolite with the admin public key
      become: true
      become_user: "{{ gitolite_user }}"
      command:
        argv:
          - "gitolite"
          - "setup"
          - "-pk"
          - "{{ gitolite_ssh_public_key_path }}"
      args:
        creates: /var/lib/gitolite/repositories/gitolite-admin.gitCode language: YAML (yaml)

The required Ansible variables: 

---
# Automating Gitolite Installation with Ansible
# License: MIT
# Author: James Cherti
# URL: https://www.jamescherti.com/ansible-install-gitolite-linux/

gitolite_user: gitolite
gitolite_group: gitolite
gitolite_shell: /bin/bash
gitolite_home: "/var/lib/{{ gitolite_user }}"
gitolite_ssh_directory: "{{ gitolite_home }}/.ssh"
gitolite_ssh_key_path: "{{ gitolite_ssh_directory }}/id_rsa"
gitolite_ssh_public_key_path: "{{ gitolite_ssh_directory }}/id_rsa.pub"Code language: YAML (yaml)

Related links

Installing Debian onto a separate partition without using the Debian installer

Reply

There are various scenarios in which one might need to install a Debian-based system (e.g., Debian, Ubuntu, etc.) from another distribution (e.g., Arch Linux, Gentoo, Debian/Ubuntu distributions, Fedora, etc.). One common reason is when a user wants to set up a Debian-based system alongside an existing distribution. This could be for the purpose of testing software compatibility, development, or simply to have a dual-boot.

A Debian-based distribution can be installed from any other distribution using debootstrap. The debootstrap command-line tool allows installing a Debian or Ubuntu base system within a subdirectory of an existing, installed system. Unlike traditional installation methods using a CD or a USB Key, debootstrap only requires access to a Debian repository.

There are several reasons why this approach is advantageous:

  • No need for a bootable USB/CD: Install Debian without external installation media.
  • Dual-boot without reinstalling the host OS: Easily add Debian alongside another Linux system.
  • Minimal and customizable installation: Install only essential packages for a lightweight system (the installer sometimes installs more than necessary).
  • Remote server installations: Install Debian on a remote machine without physical access.
  • System recovery: Reinstall or repair a broken Debian system from another Linux distribution.
  • Automated and scripted deployments: Useful for mass deployments in enterprise environments.
  • Maintaining a multi-distro workflow: Run both a stable Debian system and a rolling-release distribution.

Step 1: Create a new LVM partition, format it, and mount it

# Create the root LVM partition
lvcreate  -L 20G -n debian_root VOL_NAME

# Format the partition
mkfs.ext4 /dev/VOL_NAME/debian_root

# Mount the partition
mkdir /mnt/debian_root
mount /dev/VOL_NAME/debian_root /mnt/debian_rootCode language: plaintext (plaintext)

Step 2: Install the debootstrap command-line tool

On Arch Linux, debootstrap can be installed using:

pacman -Sy debian-archive-keyring debootstrapCode language: plaintext (plaintext)

On Gentoo, it can be installed using:

emerge -a dev-util/debootstrapCode language: plaintext (plaintext)

On Debian/Ubuntu based distributions:

apt-get install debootstrapCode language: JavaScript (javascript)

Step 3: Install the Debian base system

Use the debootstrap command to install Debian into the target directory:

debootstrap  --arch=amd64 stable /mnt/debian_root http://deb.debian.org/debianCode language: plaintext (plaintext)

You can replace stable with another Debian release like testing or unstable if desired. You can also add the flag --force-check-gpg to force checking Release file signatures.

In the above example, it will install the Debian-based system from the repository http://deb.debian.org/debian into the local directory /mnt/debian_root.

Step 4: Chroot into the Debian system

Since you are installing a Debian-based system inside another distribution (Arch Linux, Gentoo, etc.), you’ll need to ensure that the directory where the Debian system is mounted is ready. You can achieve this by mounting certain directories and chrooting into the Debian system:

sudo mount --bind /dev /mnt/debian_root/dev
sudo mount --bind /proc /mnt/debian_root/proc
sudo mount --bind /sys /mnt/debian_root/sys
sudo mount --bind /boot /mnt/debian_root/boot
sudo cp /etc/resolv.conf /mnt/debian_root/etc/resolv.conf
sudo cp /etc/fstab /mnt/debian_root/etc/fstab
sudo chroot /mnt/debian_root /bin/bash -lCode language: plaintext (plaintext)

The chroot command will open a new shell in the Debian environment.

Step 5: Configure the Debian-based system

Now that you’re inside the Debian-based system, you can configure it as desired. You can install packages, modify configurations, set up users, etc.

Here is an example:

apt-get update

# Install the Linux Kernel
apt-get install linux-image-amd64 firmware-linux-free firmware-misc-nonfree 

# Install cryptsetup if you are using a LUKS encrypted partition
apt-get install cryptsetup cryptsetup-initramfs

# Install misc packages
apt-get install console-setup vim lvm2 sudo

# Reconfigure locales
dpkg-reconfigure locales

# Configure the host name and the time zone
echo yourhostname > /etc/hostname
ln -sf /usr/share/zoneinfo/America/New_York /etc/localtime
Code language: plaintext (plaintext)

Do not forget to:

  • Modify /mnt/debian_root/etc/fstab (The mount point “/” has to point to the Debian system)
  • Modify /mnt/debian_root/etc/crypttab (If you are using a LUKS encrypted partition)

How to boot into the newly installed system?

You can, for example, configure GRUB to boot your newly configured operating system.

You can either use the new Debian-based system’s GRUB as the default (replace the existing one) or configure additional GRUB entries in an existing system. For instance, if your base system is Debian-based, you can add your entry using /etc/grub.d/40_custom:

#!/bin/sh
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.
menuentry 'Debian 2' --class debian --class gnu-linux --class gnu --class os $menuentry_id_option 'debian_fallback' {
        insmod part_gpt
        insmod fat
        search --no-floppy --fs-uuid --set=root 00000000-000a-00a0-a0a0-000000a0000a
        linux /backup/vmlinuz-6.12.12+bpo-amd64 root=/dev/MY_LVM_VOLUME/debian ro fsck.mode=auto fsck.repair=yes nowatchdog apparmor=1 acpi_backlight=native
        initrd /initrd.img-6.12.12+bpo-amd64Code language: plaintext (plaintext)

(Replace /dev/mapper/MY_LVM_VOLUME_debian with your root partition and 00000000-000a-00a0-a0a0-000000a0000a with your actual UUID that you can find using the command: lsblk -o +UUID)

In my case, I am using bootctl, which I installed using Gentoo. I simply added /boot/loader/entries/debian.conf with the following configuration:

title Debian
linux /vmlinuz-6.12.12+bpo-amd64
initrd /initrd.img-6.12.12+bpo-amd64
options rw root=/dev/volume1/debianCode language: plaintext (plaintext)

Congratulations! You have successfully installed a Debian-based system using debootstrap from another distribution such as Arch Linux, Gentoo, etc.