Blackcairn – Ops Cheat Sheet¶
Quick-reference for common, safe administrative commands on Blackcairn. Tested on Ubuntu Server 24.04 LTS.
This file is for day-to-day calm operations.
📂 Directory Listings¶
Chronological, detailed listing (oldest → newest)¶
ls -alrth --color=auto
Blackcairn alias¶
alias lb='ls -alrth --color=auto'
Reload aliases:
source ~/.bashrc
Existing aliases¶
la # ls -A (hidden files, no . or ..)
ll # compact listing (Ubuntu default)
🔐 SSH¶
Check SSH service:
systemctl status ssh
Start SSH:
sudo systemctl start ssh
Enable SSH at boot:
sudo systemctl enable ssh
Check listening port:
ss -tulpn | grep ssh
🔌 Shutdown & Reboot (Safe)¶
Recommended clean shutdown
sudo shutdown -h now
Power off (equivalent):
sudo poweroff
Reboot:
sudo reboot
Scheduled shutdown (example: 10 minutes):
sudo shutdown -h +10
Cancel scheduled shutdown:
sudo shutdown -c
🧠 System Health¶
Uptime & load:
uptime
Disk usage:
df -h
Block devices:
lsblk
📜 Logs¶
Errors from previous boot (post-incident):
sudo journalctl -b -1 -p err
Errors from current boot:
sudo journalctl -b -p err
💽 Disk Health (SMART)¶
Install tools (once):
sudo apt update
sudo apt install smartmontools
NVMe health:
sudo smartctl -a /dev/nvme0n1
SATA health:
sudo smartctl -a /dev/sda
Key indicators: - SMART overall-health: PASSED - Media/Data Integrity Errors: 0 - Reallocated sectors: 0
🌐 Networking¶
Check IPs:
ip a
Disable slow boot network wait (recommended):
sudo systemctl disable systemd-networkd-wait-online.service
🧱 Firmware / BIOS (UEFI)¶
Reboot directly into firmware setup:
sudo systemctl reboot --firmware-setup
Useful on systems with no splash screen.