Mitä suositellaan avuksi Linuxin opettelemiseen?
Omasta mielestäni linuxin vs Windowsin erot, ovat niin pieniä, ettei peruskäyttäjän tarvitse juurikaan opiskella sen käyttöä, jos on käyttänyt aiemmin Windowsia.
Kirjallisuudesta omasta mielestäni Suomeksi yksi parhaista kirjoista on Raimo Kosken: “Linux Tehokas hallinta”, mutta silläkin alkaa olla ikää…, kun kirja taitaa olla julkaistu 2010.
Lisäksi en ole pitkään aikaan vilkaissut kyseistä kirjaa, joten en muista siitä kovinkaan paljoa.
Toinen luolakirjoitusten ajalta on Ubuntu tutuksi wikikirja:
Sitäkään ei ole päivitelty vähään aikaan suuremmin.
Itse opin foorumeiden lisäksi lehdistä kuten Linux Magazine, mutta suomenkielisiä Linux-lehtiä ei käsittääkseni ole.
Linux alkaa olla varsin laaja alue opiskeltavaksi, niin ehdotuksia voisi kohdentaa lähemmäksi, jos tietäisi mihin osa-alueeseen haluaisi tietoa syvennettävän.
Lisäksi nykyään hyvnä preppaajana voi toimia AI, joka mielellään auttaa ongelmissa, jotka osaa kuvata sanoiksi. Oli se sitten Linux:sta tai jostakin muusta.
AI on nykypäivänä kätevä apu asiaan kuin asiaan, mutta omaa osaamista pitää olla, vaikka Astra 6.0 laatii valmiita käsikirjoja aiheesta kuin aiheesta, tämmöisen tuloksen sain, kun kysyin Tier2 Helpparin ohjetta Serveriin, Terminalin must-do and must-check asiat, Linux Terminal: Below are two practical tables you can use as a helpdesk emergency cheat sheet.
60 Ubuntu Bash CLI emergency helpdesk one-liners
| # | Command | What it does | Example of use |
|---|---|---|---|
| 1 | uptime |
Shows uptime and load | Check whether a server is overloaded |
| 2 | top |
Live process monitor | See what is consuming CPU right now |
| 3 | htop |
Better interactive process view | Troubleshoot a slow Ubuntu server |
| 4 | free -h |
Shows RAM and swap usage | Confirm whether memory is exhausted |
| 5 | df -h |
Shows disk space usage | Check whether / is full |
| 6 | df -i |
Shows inode usage | Find inode exhaustion when disk looks fine |
| 7 | du -sh /var/* |
Shows largest folders in /var |
Identify huge logs or cache growth |
| 8 | `du -ah / | sort -rh | head -20` |
| 9 | `ps aux --sort=-%cpu | head` | Top CPU consumers |
| 10 | `ps aux --sort=-%mem | head` | Top memory consumers |
| 11 | pgrep -fl nginx |
Finds process by name | Confirm whether nginx is running |
| 12 | pkill -f apache2 |
Kills matching process by name | Stop stuck Apache worker processes |
| 13 | kill -9 <PID> |
Force-kills a process | End a frozen process quickly |
| 14 | pstree -p |
Shows process tree | Trace parent-child stuck processes |
| 15 | `watch -n 1 "ps aux --sort=-%cpu | head"` | Repeats command every second |
| 16 | systemctl status nginx |
Shows service status | Check why website is down |
| 17 | systemctl restart nginx |
Restarts service | Recover a failed web service |
| 18 | systemctl stop nginx |
Stops service | Stop a service causing issues |
| 19 | systemctl start nginx |
Starts service | Bring service back online |
| 20 | systemctl --failed |
Lists failed services | Quick incident triage after boot |
| 21 | journalctl -xe |
Recent systemd logs | Investigate recent system errors |
| 22 | journalctl -u nginx --since "15 minutes ago" |
Service logs in time window | Check why nginx failed recently |
| 23 | journalctl -f |
Follows logs live | Watch logs during restart |
| 24 | journalctl -b |
Current boot logs | Investigate current boot problems |
| 25 | journalctl -b -1 |
Previous boot logs | Analyze crash before reboot |
| 26 | `dmesg | tail -50` | Recent kernel messages |
| 27 | tail -f /var/log/syslog |
Follows syslog live | Watch system messages during incident |
| 28 | tail -f /var/log/auth.log |
Follows auth log | Check login failures |
| 29 | grep "Failed password" /var/log/auth.log |
Finds failed SSH logins | Review brute-force attempts |
| 30 | ip a |
Shows IP addresses/interfaces | Verify server NIC and IP |
| 31 | ip route |
Shows routing table | Check default gateway issue |
| 32 | ip link |
Shows interface status | Confirm if NIC is up/down |
| 33 | ping -c 4 8.8.8.8 |
Tests raw connectivity | Verify internet reachability |
| 34 | ping -c 4 www-address |
Tests connectivity and DNS | Check if DNS works |
| 35 | ss -tuln |
Shows listening ports | Confirm app is listening |
| 36 | ss -tulpn |
Shows ports and owning processes | Identify process bound to port |
| 37 | sudo lsof -i :80 |
Shows process on a port | Find what uses port 80 |
| 38 | traceroute www-address |
Shows path to host | Investigate routing problem |
| 39 | nslookup www-address |
DNS lookup test | Check DNS response |
| 40 | dig www-address |
Detailed DNS query | Troubleshoot DNS records |
| 41 | resolvectl status |
Shows DNS resolver info | Verify configured DNS servers |
| 42 | hostname -I |
Shows local IPs only | Quickly copy server IP |
| 43 | curl -I http localhost |
Tests local HTTP response | Check if web server responds |
| 44 | wget --spider http localhost |
Tests URL reachability | Verify app health endpoint |
| 45 | `mount | column -t` | Shows mounted filesystems |
| 46 | sudo mount -o remount,rw / |
Remounts root read-write | Emergency fix for read-only root |
| 47 | find / -type f -size +100M 2>/dev/null |
Finds big files | Clean space urgently |
| 48 | find /var/log -type f -mtime +7 -delete |
Deletes old logs | Free log partition space |
| 49 | find / -mmin -60 2>/dev/null |
Finds recently modified files | Review files changed during incident |
| 50 | chmod 755 script.sh |
Fixes execute permissions | Restore script permission |
| 51 | chown www-data:www-data /var/www/html -R |
Fixes ownership | Repair website permission problem |
| 52 | whoami |
Shows current user | Confirm whether you are root |
| 53 | who |
Shows logged-in users | See active sessions |
| 54 | last |
Shows login history | Review who logged in recently |
| 55 | sudo passwd -l username |
Locks user account | Disable compromised account |
| 56 | sudo apt update |
Refreshes package list | Prepare for updates or installs |
| 57 | sudo apt upgrade -y |
Installs updates | Apply urgent package fixes |
| 58 | sudo apt --fix-broken install |
Repairs broken package state | Resolve interrupted install issue |
| 59 | sudo dpkg --configure -a |
Finishes incomplete package config | Recover from failed upgrade |
| 60 | sudo reboot |
Reboots the system | Final recovery step after fixes |