📊 System Resource Monitoring with top and htop in AlmaLinux: Beginner’s Guide

Is your AlmaLinux system running slow? Want to see what’s using all your CPU or memory? 🤔 Let’s learn how to monitor your system like a pro using top and htop! These tools show you everything happening in your computer in real-time. It’s like having X-ray vision for your system! 👁️✨

🤔 Why is System Monitoring Important?

Keeping an eye on your system helps you catch problems before they get serious! Here’s why monitoring rocks:

• 🚀 Find Slow Programs - See what’s making your system sluggish
• 💾 Memory Management - Know when you’re running out of RAM
• 🔥 CPU Usage - Identify programs hogging your processor
• 🐛 Catch Problems Early - Spot issues before crashes
• 📈 Performance Tuning - Make your system run faster
• 🛡️ Security - Detect suspicious processes

🎯 What You Need

Before we start monitoring, make sure you have:

• ✅ AlmaLinux system running
• ✅ Terminal access
• ✅ Basic command line skills
• ✅ 5 minutes to learn
• ✅ Curiosity about your system!

📝 Step 1: Using the top Command

top is installed by default and shows live system info! 📺

Start top

# Simply type:
top

# Or with options:
top -u username    # Show only one user's processes
top -p 1234        # Monitor specific process ID

Example output:

top - 14:30:25 up 5 days, 3:15, 2 users, load average: 0.15, 0.20, 0.18
Tasks: 125 total, 1 running, 124 sleeping, 0 stopped, 0 zombie
%Cpu(s): 2.5 us, 1.0 sy, 0.0 ni, 96.5 id, 0.0 wa, 0.0 hi, 0.0 si
MiB Mem: 7821.0 total, 2145.3 free, 3421.7 used, 2254.0 buff/cache
MiB Swap: 2048.0 total, 2048.0 free, 0.0 used, 3987.2 avail Mem

PID USER    PR  NI   VIRT   RES   SHR S  %CPU  %MEM    TIME+ COMMAND
1234 john   20   0  512000 45236  8920 S   5.3   0.6  12:34.56 firefox
5678 root   20   0  225544 11240  7832 S   2.0   0.1   1:23.45 systemd

What this shows: 📖

• load average = System load (lower is better)
• %Cpu(s) = CPU usage breakdown
• MiB Mem = Memory usage
• PID = Process ID number
• %CPU = CPU usage per process
• %MEM = Memory usage per process

Keyboard Shortcuts in top

# While top is running, press:
h     # Help menu
q     # Quit top
k     # Kill a process
r     # Renice (change priority)
M     # Sort by memory usage
P     # Sort by CPU usage
1     # Show individual CPU cores
c     # Show full command paths

🔧 Step 2: Installing and Using htop

htop is like top but prettier and easier! 🌈

Install htop

# Install htop
sudo dnf install -y htop

# Verify installation
htop --version

Start htop

# Just type:
htop

# Or with options:
htop -u username   # Show specific user
htop -t            # Tree view (shows parent/child)

Pro tip: 💡 htop uses colors! Green = normal, red = kernel, blue = low priority

🌟 Step 3: Understanding the Display

Let’s decode what you’re seeing! 🔍

CPU Meters

# In htop, CPU bars show:
[||||||||  ] 80%   # Green = user processes
[||        ] 20%   # Red = system/kernel
[|         ] 10%   # Blue = low priority

# Multiple cores shown as:
1 [||||      ] 40%
2 [||||||||||] 100%  # This core is maxed out!
3 [||        ] 20%
4 [|||       ] 30%

Memory Bar

# Memory display:
Mem[|||||||||||||     ] 4.2G/8.0G   # Green = used
Swp[                  ] 0K/2.00G     # Yellow = cache

Process List

# Columns explained:
PID    # Process ID (unique number)
USER   # Who owns the process
PRI    # Priority (lower = higher priority)
NI     # Nice value (process politeness)
VIRT   # Virtual memory size
RES    # Physical RAM used
SHR    # Shared memory
S      # State (S=sleeping, R=running)
CPU%   # CPU usage percentage
MEM%   # Memory usage percentage
TIME+  # Total CPU time used
Command # What's running

✅ Step 4: Common Monitoring Tasks

Let’s do some real monitoring! 🎯

Find Memory Hogs

# In htop, press:
F6    # Sort menu
↓     # Arrow down to MEM%
Enter # Sort by memory

# Or in top:
M     # Sort by memory instantly

Kill Problematic Process

# In htop:
# 1. Arrow keys to select process
# 2. Press F9 for kill menu
# 3. Choose signal (usually 15 SIGTERM)
# 4. Press Enter

# In top:
k          # Press k
[PID]      # Enter process ID
[signal]   # Press Enter for default (15)

Monitor Specific Program

# Watch Firefox only:
top -p $(pgrep firefox)

# Or in htop:
F4         # Filter
firefox    # Type program name
Enter      # Apply filter

🎮 Quick Examples

Example 1: Check What’s Slowing You Down 🐌

# Start htop
htop

# Press F6 (Sort)
# Select CPU%
# Press Enter

# Now you see the CPU hogs at the top!
# If something uses 100% CPU constantly, that's your problem!

Example 2: Monitor During Heavy Task 💪

# Open two terminals

# Terminal 1: Start monitoring
htop

# Terminal 2: Run heavy task
tar -czf backup.tar.gz /large/directory

# Watch htop to see:
# - CPU spike during compression
# - Memory usage increase
# - Disk I/O activity

Example 3: Create Monitoring Script 📜

# Create monitor.sh
nano ~/monitor.sh

#!/bin/bash
echo "=== System Health Check ==="
echo "Date: $(date)"
echo ""
echo "Memory Usage:"
free -h
echo ""
echo "CPU Load:"
uptime
echo ""
echo "Top 5 CPU processes:"
ps aux | sort -rk 3,3 | head -6
echo ""
echo "Top 5 Memory processes:"
ps aux | sort -rk 4,4 | head -6

# Make executable
chmod +x ~/monitor.sh

# Run it
./monitor.sh

🚨 Fix Common Problems

Problem 1: System very slow ❌

Symptoms:

• Everything takes forever
• Mouse barely moves
• Can’t open programs

Try this:

# Quick check in terminal
top -b -n 1 | head -20

# Look for:
# - Load average > number of CPUs
# - CPU% near 100%
# - Memory full

# Emergency fix:
killall firefox   # Or whatever's using most resources

Problem 2: Can’t see all processes ❌

Try this:

# Run as root to see everything
sudo htop

# In top, toggle views:
V     # Forest view (tree)
H     # Show threads
u     # Filter by user

Problem 3: Numbers changing too fast ❌

Slow down the refresh:

# In top:
d     # Change delay
3     # Enter 3 seconds
Enter # Apply

# Start htop with slower refresh:
htop -d 30   # Update every 3 seconds

📋 Simple Commands Summary

💡 Tips for Success

1. Check Regularly 📅 - Monitor weekly to know what’s normal
2. Learn Your Baseline 📊 - Know your system’s usual numbers
3. Don’t Panic 😌 - High CPU/memory isn’t always bad
4. Use Colors 🎨 - htop’s colors make things clearer
5. Take Screenshots 📸 - Save output when debugging

🏆 What You Learned

You’re now a monitoring master! You can:

• ✅ Use top to monitor system resources
• ✅ Navigate htop’s colorful interface
• ✅ Find resource-hungry processes
• ✅ Kill problematic programs safely
• ✅ Sort and filter process lists
• ✅ Understand CPU and memory usage

🎯 Why This Matters

Now you can:

• 🚀 Keep your system running smoothly
• 🔍 Diagnose performance problems quickly
• 💾 Manage memory usage effectively
• 🛡️ Spot suspicious activity
• 📈 Optimize system performance
• 🐛 Debug issues like a pro

Remember: Regular monitoring prevents big problems! Check your system weekly and you’ll catch issues early! ⭐

Happy monitoring! Your AlmaLinux system is now under your watchful eye! 👁️🎉