machines/content/posts/sentinel.md

title	date	draft	toc
Setup sentinel (Ubuntu Server arm64)	2022-07-23T08:00:20+05:30	false	true

Stage 0000: Flash SD Card

Verify the checksum first

echo "<CHECKSUM> *ubuntu-VERSION-preinstalled-desktop-arm64+raspi.img.xz" | shasum --check

Flash the SD Card

xzcat ubuntu-VERSION-preinstalled-desktop-arm64+raspi.img.xz | sudo dd status=progress bs=4M of=/dev/XXX

sync && sync && sync

sudo eject /dev/XXX

Stage 0001: Immediate initial setup

Set hostname

sudo hostnamectl set-hostname sentinel

Set timezone

sudo timedatectl set-timezone Asia/Kolkata

Set DNS Servers

nmcli connection modify "$(nmcli -g name,device connection show | grep "eth0" | cut -f1 -d":")" ipv4.dns "1.1.1.2,1.0.0.2"
nmcli connection modify "$(nmcli -g name,device connection show | grep "eth0" | cut -f1 -d":")" ipv4.ignore-auto-dns yes

REBOOT! (hostname needs to come in effect)

sudo reboot +0

Stop, mask and disable services

sudo systemctl stop sleep.target suspend.target hibernate.target hybrid-sleep.target
sudo systemctl disable sleep.target suspend.target hibernate.target hybrid-sleep.target
sudo systemctl mask sleep.target suspend.target hibernate.target hybrid-sleep.target

Change "boot args"

sudoedit /boot/firmware/usercfg.txt

Add the following lines to it:

hdmi_force_hotplug=1
disable_overscan=1

arm_freq=2000

Generate SSH Keys

cd $HOME/.ssh
ssh-keygen -t ed25519 -f bluefeds
ssh-keygen -t ed25519 -f gitea
ssh-keygen -t ed25519 -f github
ssh-keygen -t ed25519 -f gitlab

Reboot

sudo reboot +0

Stage 0010

Upgrade packages

sudo apt-get update
sudo apt-get upgrade

Reboot

sudo reboot +0

Stage 0011

Install packages

sudo apt-get install apache2 aria2 bat bc cifs-utils cmatrix curl exfat-fuse exfat-utils fd-find ffmpeg findutils git glances hdparm htop iotop iperf3 jq libpam-google-authenticator locate mediainfo mpv neofetch neovim nload openssh-server python3 python3-pip rename rsync samba samba-common-bin smartmontools speedtest-cli tldr tmux transmission-cli transmission-common transmission-daemon tree unrar unzip valgrind vim webp wget wget2 wireguard xz-utils yt-dlp zfs-dkms zip zsh zsh-autosuggestions zsh-syntax-highlighting

chsh -s $(which zsh) $(whoami)

vim-plug (Neovim)

sh -c 'curl -fLo "${XDG_DATA_HOME:-$HOME/.local/share}"/nvim/site/autoload/plug.vim --create-dirs https://raw.githubusercontent.com/junegunn/vim-plug/master/plug.vim'

Open nvim and type :PlugInstall

Stage 0100: ZFS

Install ZFS if not already installed

Don't use zfsutils-linux, it depends on Ubuntu's kernel inclusions

sudo apt-get install zfs-dkms

Enable necessary services

sudo systemctl enable zfs-import-cache.service
sudo systemctl enable zfs-import-scan.service
sudo systemctl enable zfs-mount.service
sudo systemctl enable zfs-share.service
sudo systemctl enable zfs.target
sudo systemctl enable zfs-zed.service

Make sure an import cache file exists

sudo zpool set cachefile=/etc/zfs/zpool.cache vaikuntham

Creating a new zpool?

sudo zpool create -o ashift=12 vaikuntham /dev/sda

sudo zfs set atime=off vaikuntham
sudo zfs set primarycache=all vaikuntham
sudo zfs set recordsize=1M vaikuntham
sudo zfs set xattr=sa vaikuntham

sudo zfs create vaikuntham/backups
sudo zfs create vaikuntham/torrents
sudo zfs set recordsize=16K vaikuntham

sudo chown ubuntu:ubuntu -vR /vaikuntham

sudo zfs allow -u ubuntu compression,mountpoint,create,mount,receive vaikuntham

sudo zpool export vaikuntham

sudo zpool import
sudo zpool import -d /dev/disk/by-id <pool-id>

sudo zpool set cachefile=/etc/zfs/zpool.cache vaikuntham

zpool status -v
zfs list

sudo zpool scrub vaikuntham

Reboot

sudo reboot +0

Stage 0101: cron

user crontab

# always add ">/dev/null 2>&1" at the end of cronjobs
# to prevnet a `dead.letter` in $HOME/

root crontab

# always add ">/dev/null 2>&1" at the end of cronjobs
# to prevnet a `dead.letter` in $HOME/


# start scrub
# on the first Friday of every month
# at 1845 hours
45 18 * * 5 [ $(date +\%d) -le 07 ] && /sbin/zpool scrub libertine >/dev/null 2>&1


# backup .torrent files
# chmod and chown
# rm .macos files
30 18 * * * bash /home/ubuntu/.scripts/_sentinel/cron/root/midnight.sh >/dev/null 2>&1


# update fs database every 6 hours
* */6 * * * updatedb >/dev/null 2>&1