Linux Process Management Cheat Sheet

📋 Kopieren Sie alle Befehle PDF generieren

Überblick

Linux Prozessmanagement beinhaltet die Überwachung, Steuerung und Optimierung von laufenden Prozessen und Systemressourcen. Dieser umfassende Leitfaden umfasst Prozessüberwachungstools, Signalhandling, Jobsteuerung, Systemressourcenmanagement und Leistungsoptimierungstechniken, die für Systemadministratoren und IT-Profis unerlässlich sind.

ZEIT Warning: Prozessabbruchbefehle wie kill -9 können Datenverlust verursachen. Versuchen Sie immer anmutige Kündigung zuerst und stellen Sie richtige Backups.

Prozessansicht und Überwachung

Grundlegende Prozessinformationen

```bash

Display running processes

ps ps aux # All processes with detailed info ps -ef # Full format listing ps -u username # Processes for specific user ps -p PID # Specific process by PID

Process tree view

pstree pstree -p # Show PIDs pstree username # Processes for specific user

Real-time process monitoring

top htop # Enhanced interactive process viewer ```_

Erweiterte Prozessüberwachung

```bash

Detailed process information

ps auxf # Process tree format ps -eo pid,ppid,cmd,pcpu,pmem # Custom columns

Process by resource usage

ps aux --sort=-pcpu # Sort by CPU usage ps aux --sort=-pmem # Sort by memory usage

Long-running processes

ps -eo pid,etime,cmd # Show elapsed time

Zombie processes

ps aux|grep -w Z ps -eo stat,pid,cmd|grep -w Z ```_

Echtzeit-Systemüberwachung

```bash

Interactive process monitor

top

Top commands:

k - kill process

r - renice process

M - sort by memory

P - sort by CPU

q - quit

Enhanced process monitor

htop

htop features:

F9 - kill process

F7/F8 - nice/renice

F6 - sort options

F10 - quit

System activity reporter

sar -u 1 10 # CPU usage every 1 second, 10 times sar -r 1 10 # Memory usage sar -d 1 10 # Disk activity ```_

Prozesssteuerung und Signale

Signaltypen

```bash

Common signals:

SIGTERM (15) - Graceful termination

SIGKILL (9) - Force kill (cannot be caught)

SIGHUP (1) - Hangup (reload config)

SIGSTOP (19) - Stop process

SIGCONT (18) - Continue stopped process

SIGINT (2) - Interrupt (Ctrl+C)

```_

Killing Processes

```bash

Kill by PID

kill PID kill -15 PID # Send SIGTERM (default) kill -9 PID # Force kill with SIGKILL kill -HUP PID # Send hangup signal

Kill by process name

killall process_name killall -9 process_name

Kill by pattern

pkill pattern pkill -f pattern # Match full command line pkill -u username # Kill user's processes

Interactive process killer

top # Press 'k' then enter PID htop # Press F9 then select process ```_

Prozesspriorität und Nizza Werte

```bash

View process priorities

ps -eo pid,ni,cmd

Start process with specific priority

nice -n 10 command # Lower priority (+10) nice -n -5 command # Higher priority (-5)

Change running process priority

renice 10 PID # Set nice value to 10 renice -5 -p PID # Set nice value to -5 renice 5 -u username # Renice all user processes ```_

Job Control

Hintergrund und Vordergrund Jobs

```bash

Run command in background

command &

List active jobs

jobs jobs -l # Show PIDs

Bring job to foreground

fg fg %1 # Bring job 1 to foreground

Send job to background

bg bg %1 # Send job 1 to background

Suspend current job

Ctrl+Z

Resume suspended job

fg # Resume in foreground bg # Resume in background ```_

Dauerhafte Prozesse

```bash

Run command immune to hangups

nohup command & nohup command > output.log 2>&1 &

Detach from terminal

disown %1 # Disown job 1 disown -a # Disown all jobs

Screen sessions

screen # Start new session screen -S name # Named session screen -r # Reattach to session screen -ls # List sessions

Tmux sessions

tmux # Start new session tmux new -s name # Named session tmux attach -t name # Attach to session tmux list-sessions # List sessions ```_

Systemressourcenüberwachung

CPU Überwachung

```bash

CPU usage overview

top htop vmstat 1 # Virtual memory statistics iostat 1 # I/O and CPU statistics

Per-CPU statistics

mpstat # Multi-processor statistics mpstat -P ALL 1 # All CPUs every second

CPU load averages

uptime w # Who is logged in and load cat /proc/loadavg # Load average file ```_

Speicherüberwachung

```bash

Memory usage

free free -h # Human readable free -m # In megabytes free -s 1 # Update every second

Detailed memory information

cat /proc/meminfo vmstat 1 # Virtual memory stats

Memory usage by process

ps aux --sort=-pmem|head -10 top -o %MEM # Sort by memory in top

Memory map of process

pmap PID pmap -d PID # Detailed mapping ```_

Disk I/O Monitoring

```bash

Disk usage

df -h # Filesystem usage du -sh /path # Directory usage

I/O statistics

iostat iostat -x 1 # Extended stats every second iotop # Real-time I/O monitoring

Disk activity by process

iotop -o # Only show active processes pidstat -d 1 # Per-process I/O stats ```_

Netzwerküberwachung

```bash

Network connections

netstat -tuln # TCP/UDP listening ports ss -tuln # Modern replacement for netstat ss -p # Show process names

Network activity

netstat -i # Interface statistics iftop # Real-time network usage nethogs # Network usage by process

Network connections by process

lsof -i # Network files lsof -i :80 # Processes using port 80 ```_

Prozessanalyse und Debugging

Informationen zum Thema

```bash

Detailed process info

cat /proc/PID/status cat /proc/PID/cmdline cat /proc/PID/environ

Process file descriptors

lsof -p PID ls -la /proc/PID/fd/

Process memory maps

cat /proc/PID/maps pmap PID

Process threads

ps -T -p PID top -H -p PID ```_

Systemanrufe und Debugging

```bash

Trace system calls

strace command strace -p PID # Attach to running process strace -f command # Follow forks

Library calls

ltrace command ltrace -p PID

Debug running process

gdb -p PID ```_

Leistungsanalyse

```bash

Process CPU usage over time

pidstat 1 # Per-process statistics pidstat -p PID 1 # Specific process

Memory usage tracking

pidstat -r 1 # Memory statistics pidstat -d 1 # Disk I/O statistics

System performance overview

vmstat 1 10 # Virtual memory stats sar -A # All system activity ```_

Systemdienstleistungen und Daemons

Systemisches Servicemanagement

```bash

Service status

systemctl status service_name systemctl is-active service_name systemctl is-enabled service_name

Start/stop services

systemctl start service_name systemctl stop service_name systemctl restart service_name systemctl reload service_name

Enable/disable services

systemctl enable service_name systemctl disable service_name

List services

systemctl list-units --type=service systemctl list-units --failed ```_

Service Logs

```bash

View service logs

journalctl -u service_name journalctl -u service_name -f # Follow logs journalctl -u service_name --since today

System logs

journalctl journalctl -f # Follow system logs journalctl --since "1 hour ago" journalctl -p err # Error messages only ```_

Prozessautomatisierung und -planung

Cron Jobs

```bash

Edit crontab

crontab -e crontab -l # List cron jobs crontab -r # Remove all cron jobs

System cron directories

ls /etc/cron.d/ ls /etc/cron.daily/ ls /etc/cron.hourly/ ls /etc/cron.weekly/ ls /etc/cron.monthly/

Cron log

tail -f /var/log/cron ```_

Bei Jobs (Einmalige Planung)

```bash

Schedule one-time job

at 15:30 at now + 1 hour at tomorrow

List scheduled jobs

atq at -l

Remove scheduled job

atrm job_number ```_

Probleme bei der Fehlerbehebung

Hohe CPU Verwendung

```bash

Find CPU-intensive processes

top -o %CPU ps aux --sort=-pcpu|head -10

CPU usage by command

pidstat -u 1

System load investigation

uptime vmstat 1 sar -u 1 10 ```_

Hohe Speichernutzung

```bash

Memory-intensive processes

ps aux --sort=-pmem|head -10 top -o %MEM

Memory leaks detection

valgrind --leak-check=full command

Out of memory investigation

dmesg|grep -i "killed process" grep -i "out of memory" /var/log/messages ```_

Zombie Prozesse

```bash

Find zombie processes

ps aux|awk '$8 ~ /^Z/ \\{ print $2 \\}' ps -eo stat,pid,cmd|grep -w Z

Kill parent of zombie

ps -o ppid= -p zombie_pid kill parent_pid ```_

Prozess nicht reagieren

```bash

Check if process is hung

kill -0 PID # Test if process exists strace -p PID # See what process is doing

Force termination

kill -TERM PID # Try graceful first sleep 5 kill -KILL PID # Force if necessary ```_

Leistungsoptimierung

Prozessbeschränkungen

```bash

View current limits

ulimit -a cat /proc/PID/limits

Set limits

ulimit -n 4096 # File descriptors ulimit -u 1024 # Max user processes ulimit -m 1048576 # Memory limit (KB)

System-wide limits

cat /etc/security/limits.conf ```_

CPU Affinität

```bash

View CPU affinity

taskset -p PID

Set CPU affinity

taskset -p 0x1 PID # CPU 0 only taskset -p 0x3 PID # CPU 0 and 1 taskset -c 0,1 PID # CPU 0 and 1

Start process with affinity

taskset -c 0 command ```_

Ressourcen

• [Linux Process Management Guide](__LINK_4___ -%20Systemd%20Dokumentation
• (__LINK_4___)
• (__LINK_4___)

--

*Dieses Cheatsheet bietet umfassende Prozessmanagement-Befehle für Linux-Systeme. Verstehen Sie immer die Auswirkungen von Prozesssteuerungsbefehlen, bevor Sie sie in Produktionsumgebungen verwenden. *