# Arch System

Use for system state, maintenance, upgrades, health.

## First Read-only Probes

```sh
cat /etc/os-release
uname -a
pacman -Q pacman 2>/dev/null
systemctl --failed
journalctl -b --no-pager -p warning..alert
pacman -Qm
pacman -Qtdq
```

Do not infer Arch from `pacman` alone; read `/etc/os-release`.

## Upgrade Discipline

- Read `https://archlinux.org/news/` before upgrade guidance.
- Full upgrades only:
  `pacman -Syu`.
- Never advise `pacman -Sy <pkg>`.
- Keep rescue/live media in mind for risky kernel/boot/glibc/systemd updates.
- After upgrade:
  review pacman output, handle `.pacnew`, restart affected services or reboot.
- AUR/local packages are user's responsibility; rebuild when deps/ABI change.

## Maintenance Checks

```sh
systemctl --failed
journalctl -b --no-pager
pacman -Qtdq          # orphan deps
pacman -Qm            # foreign/local/AUR packages
pacman -Qkk           # file integrity; can be noisy
```

Package cache:

- Prefer `paccache` from `pacman-contrib` over aggressive `pacman -Scc`.
- Preserve rollback ability unless disk pressure is real.

Config drift:

```sh
find /etc -name '*.pacnew' -o -name '*.pacsave'
grep -E '\.pac(new|save)' /var/log/pacman.log
```

Use `pacdiff` if present.

## Current Sources

- Wiki:
  `System maintenance`, `Pacman`, `Pacman/Pacnew and Pacsave`
- Man:
  `pacman(8)`, `paccache(8)`, `pacdiff(8)`