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Installing Arch Linux on an Old ThinkPad

#programming #linux #homelab #computers

Updated 24 Jan 2025

Last year, I installed Arch Linux on an old Lenovo ThinkPad. I did this for a few reasons:

  1. I wanted to deepen my knowledge of Linux but also computers more generally.
  2. A lot of developers I respect have given up on Mac and Windows in favor of using Linux.
  3. I was curious as to how much I could get done with a stripped down Linux machine.

I found an old Lenovo ThinkPad on Facebook Marketplace and bought it. For $200, I got a laptop with a 7th gen Core-i5, a 256GB SSD, and 16GB of memory. It also had two batteries installed and came with a power adapter so that was nice. I started by following a tutorial for the main installation but eventually abandoned it in favor of the Arch wiki and ChatGPT. Below are some of the things I learned along the way.

Disk partitioning and encryption with LUKS

After downloading the ISO and adding it to my Ventoy drive, I booted into Arch, made sure I had a network connection, and made sure the OpenSSH daemon was running. Then I ssh'd into the ThinkPad from my Mac.

After using fdisk to create partitions, I ran lvcreate -L 32G archie1 -n root to create a logical volume for root and lvcreate -l 100%FREE archie1 -n home to use the rest of my disk for the home directory. I then created the filesystems per the docs. I went with ext4 since I didn't need the features of something like zfs. For the boot partition, I ran mkfs.fat -F32 /dev/nvme0n1p1 to make a fat32 file system. Then I mounted my boot partition with mount --mkdir /dev/nvme0n1p1 /mnt/boot.

I won't go into the details of encrypting the partition with LUKS -- I basically followed the docs on the Arch Wiki. I will share that I forgot to mount my home directory before moving on and had to go back after I finished most of the installation process to figure out what I did wrong. I also still don't fully understand how mounting block devices works under the hood. But after this install, I definitely know how to use lsblk and other utilities way better.

After I generated an fstab file with genfstab -U /mnt >> /mnt/etc/fstab, I ran arch-chroot /mnt to change the root of my session to the filesystem at /mnt and continued with the installation.

Networking, initramfs, boot loader

I went with systemd-networkd as my network manager. It's a little more work than something like NetworkManager but you get to learn more about the internals. I installed resolved which is important for DNS resolution. I also installed iwd and enabled it. I made sure to enable all of these services (networkd, resolved, and iwd) so that when I went to reboot the machine, I would have the tools I needed to connect to the internet.

Because I encrypted my drive, I needed to modify the mkinitcpio.conf file so that my initramfs had all the things needed to decrypt my volume at boot. Basically, initramfs is a very small, temporary user space that is loaded into ram before systemd starts. I needed the following hooks in /etc/mkinitcpio.conf:

HOOKS=(base systemd autodetect microcode modconf kms keyboard sd-vconsole block sd-encrypt lvm2 filesystems fsck)

I used systemd-boot which is only available for UEFI partitions, not for BIOS partitions. I needed to install it by running bootctl install. I had some issues because I hadn't properly mounted my /boot partition. Then, I configured my boot loader by creating an entry at /boot/loader/entries/arch.conf. One fun thing I learned about during this part of the process is the boot order on modern systems:

  1. POST (power on self-test) — searches for a BIOS installed on your motherboard
  2. BIOS (Basic I/O system) — searches for a boot loader on your disk
  3. Boot loader — boots an OS
  4. OS — starts with the init process
  5. Init process (usually systemd which replaced SysV)

The last thing I did before exiting chroot and booting was create my user and password and adding myself to the wheel group. After booting into the system, I installed Hyprland as my desktop environment, Firefox for web browsing, Obsidian for notes, and Alacritty for my terminal.

Key lessons learned

I'm happy to report that I'm still using the machine and frankly, I'm loving it. One huge takeaway is that I now default to using man pages whenever I need to fix something. Google and ChatGPT are great but searching a man page for a keyword is so fast. It's also just so cool to have all the information you need on your system, with or without an internet connection.

I have frankly been surprised by how much work I can get done on this machine. However, it's not a replacement for my Mac. For example, I recently I had to install some terrible application in order to take a test for an AWS cert and I literally wouldn't have been able to do it in the time I had without my Mac. As much as I love Arch, there are just too many things that require hours upon hours of debugging and configuring. For the basics, it's great. But much like Neovim, it can be a real hassle to use once you start trying to do complicated things. Still, it's nice to know that if Apple ever forced my hand, I could use Linux as a daily driver.