mikaela.github.io/n/essentialsoftware.md

Essential software for new systems

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Automaattinen sisällysluettelo / Automatically generated Table of Contents

• Security
• Usability
• Offtopic system configuration
  • Debian-based
    • Terminus on Fedora
    • Terminus on Arch Linux
  • SSD
  • BTRFS

Security

• microcode - propietary, but otherwise CPU holes are going to be gaping open. Refer to tail -n +1 /sys/devices/system/cpu/vulnerabilities/*
  • Debian calls this as amd64-microcode or intel-microcode
  • Arch knows them as amd-ucode or intel-ucode and won’t load it for you, you will have to initrd /intel-ucode.img yourself instantly after linux and before initrd /initramfs-linux-lts.img…
• ufw for Deb-based or firewalld on Fedora (and Kali and Arch Linux, if you so choose in the last)
• sshguard for mitigating shared systems where others refuse to use keys
• needrestart for knowing when updates actually require services to be restarted or a kernel upgrade happens and requires reboot
  • Arch users may prefer checkservices from archlinux-contrib
• molly-guard so you won’t accidentally reboot or poweroff production rather than local machine.
• apt-listchanges changelogs are worth knowing when updating.
• apt-listbugs known bugs are especially nice when performing bigger updates.
• chrony - security demands the time to be correct, Chrony supports NTS and is proper NTP server instead of just SNTP like systemd-timesyncd.
  • alternatively configure systemd-timesyncd
• unbound - my choice for both DNSSEC validating and DNS-over-TLS, even if I had it connect to upstream dns[crypt]proxy
  • alternatively configure systemd-resolved. Simultaneously systemd-networkd may be a good idea.
• unattended-upgrades or dnf-automatic so security updates are at least downloaded if not even directly installed (see configuration and systemd units!)
  • if dnf-automatic, consider sudo systemctl enable dnf-automatic-install.{timer,service} or at least sudo systemctl enable dnf-automatic-download.{timer,service}

Usability

• nvim git tmux zsh - good luck without these
• if cryptographic operations are taking ages, consider something like haveged. It’s controversial, so if there are no issues, don’t install a random number generator.
• userspace oom killer, may avoid frozen systems, much more pleasant than actually having to deal with a frozen system.
  • earlyoom
    • remember to sudo systemctl enable --now earlyoom
  • systemd-oomd
    • remember to sudo systemctl enable --now systemd-oomd
• zram-tools - small compressed swap in RAM
  • Remember to check configs! Fedora: /etc/zram.conf
  • sudo systemctl enable --now zramswap.service zram-swap.service
• thermald for additional help keeping system cool, especially intel
  • sudo systemctl enable --now thermald
• vnstat - help for observing bandwidth usage
• yggdrasil - essential for getting through Carrier Grade NAT whether there is IPv6 or not. Also gives static internal IPv6 reducing need for dynamic DNS.
• tlp - for laptop power management, especially ThinkPad.
  • sudo tlp-stat | less
  • sudo systemctl enable --now tlp

Offtopic system configuration

This is just too close to not mention here (and was besides in my planning issue):

Debian-based

• sudo dpkg-reconfigure console-setup
  • ensure UTF-8 and select Terminus
• sudo dpkg-reconfigure keyboard-configuration
  • compose key

Terminus on Fedora

After installing the package, adjust /etc/vconsole.conf e.g.:

KEYMAP="fi"
FONT="ter-v16v"

Maybe sudo updatedb and locate ter-v16v at first though?

Terminus on Arch Linux

See Fedora, but change the FONT to "ter-132b" instead.

SSD

• sudo systemctl enable --now fstrim.timer
• check that /etc/fstab has noatime so every file access isn’t written to the disk. BTRFS filesystems should also have ssd flag.
  • NEVER ENABLE atime, relatime or norelatime under the threat of suffering especially on BTRFS. I have been doing fine without it for years, it will not help any issue, unless you want read operations to cause writes and eat space…

BTRFS

• The above applies, /etc/fstab must have noatime.
• compress=zstd:0 may be helpful. It enables zstd compression, which is an integrated feature of BTRFS, with the default compression level (3 at the time of writing). The BTRFS devs are most likely wiser than me and can provide a reasonable balance between efficiency and CPU use.
  • Alternatively compress-force=zstd:0 may be used, but that might bring extra CPU usage in compressing what cannot be compressed.
    • Test on Lumina: 20G free -> 24G free.
  • The compression will happen either the next time the file is written or can be manually triggered through sudo btrfs filesystem defragment -r "$PWD"