Troubleshooting Performance Issues: Boot & Performance Problem Solving

Master the art of Linux troubleshooting with this comprehensive guide to performance and boot issues. Learn systematic approaches, diagnostic tools, and proven solutions for resolving slow systems, boot failures, and performance bottlenecks used by system administrators worldwide.

The Troubleshooting Mindset

Effective troubleshooting requires a systematic approach. Follow these principles:

Start Simple: Check basic issues before diving deep
Gather Evidence: Collect logs and metrics before making changes
Isolate Problems: Determine if issue is hardware, software, or configuration
Document Everything: Track what you've tried and what worked
Test Incrementally: Make one change at a time and test results

Identify Symptoms
What exactly is wrong? Slow response? Won't boot? Service down?

Gather Information
Check logs, monitor resources, reproduce the issue

Form Hypothesis
Based on evidence, what could be causing the problem?

Test Hypothesis
Run diagnostic commands, test solutions, verify fixes

Implement Solution
Apply fix, monitor results, document resolution

1. Boot Issues Troubleshooting

❌

System Won't Boot

Black screen, boot loop, or kernel panic

Boot from recovery/live CD/USB

Check disk for errors: fsck /dev/sda1

Examine boot logs: journalctl -xb

Check GRUB configuration

Test hardware components

🐢

Slow Boot Time

System takes minutes to boot

Analyze boot process: systemd-analyze

Identify slow services: systemd-analyze blame

Check disk I/O during boot

Disable unnecessary services

Optimize filesystem mounting

🔒

Filesystem Issues

"Read-only filesystem" or disk errors

Boot to single-user mode

Run filesystem check: fsck -y /dev/sda1

Check disk health: smartctl -a /dev/sda

Check /etc/fstab for errors

Check disk space

Boot Diagnostic Commands

# Analyze boot time

systemd-analyze

systemd-analyze blame

systemd-analyze critical-chain

systemd-analyze plot > boot.svg

# View boot logs

journalctl -b # Current boot

journalctl -b -1 # Previous boot

journalctl -xb # With explanations

dmesg | less # Kernel messages

# Filesystem checks

fsck /dev/sda1 # Check filesystem

mount | grep "^/dev" # Check mounts

blkid # Show block devices

lsblk # List block devices

# GRUB troubleshooting

grub-install /dev/sda # Reinstall GRUB

update-grub # Update GRUB config

cat /boot/grub/grub.cfg # View GRUB config

Boot Timeline Analysis

0-5 seconds

BIOS/UEFI Initialization
Hardware detection, firmware initialization

5-10 seconds

Bootloader (GRUB)
Load kernel and initramfs

10-20 seconds

Kernel Initialization
Hardware drivers, filesystem setup

20-60+ seconds

Systemd Services
Network, login manager, user services

Boot Issue Resolution Script

#!/bin/bash
# boot-troubleshooter.sh
# Comprehensive boot issue diagnostics

REPORT_FILE="/tmp/boot-diagnostics-$(date +%Y%m%d_%H%M%S).txt"

echo "=== Boot Troubleshooting Diagnostics ===" > "$REPORT_FILE"
echo "Generated: $(date)" >> "$REPORT_FILE"
echo "Hostname: $(hostname)" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

# 1. Systemd boot analysis
echo "1. SYSTEMD BOOT ANALYSIS" >> "$REPORT_FILE"
echo "=======================" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Total boot time:" >> "$REPORT_FILE"
systemd-analyze 2>&1 >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Service initialization times:" >> "$REPORT_FILE"
systemd-analyze blame 2>&1 | head -20 >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Critical chain (slowest services):" >> "$REPORT_FILE"
systemd-analyze critical-chain 2>&1 | head -20 >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

# 2. Filesystem checks
echo "2. FILESYSTEM STATUS" >> "$REPORT_FILE"
echo "====================" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Mounted filesystems:" >> "$REPORT_FILE"
mount | grep "^/dev" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Disk space:" >> "$REPORT_FILE"
df -h >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Inode usage:" >> "$REPORT_FILE"
df -i >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

# 3. Boot logs
echo "3. BOOT LOGS" >> "$REPORT_FILE"
echo "============" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Recent kernel messages:" >> "$REPORT_FILE"
dmesg | tail -50 >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Current boot errors:" >> "$REPORT_FILE"
journalctl -b -p err 2>&1 | tail -20 >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

# 4. Hardware status
echo "4. HARDWARE STATUS" >> "$REPORT_FILE"
echo "==================" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Memory status:" >> "$REPORT_FILE"
free -h >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "CPU information:" >> "$REPORT_FILE"
lscpu | grep -E "Model name|CPU\(s\)|Thread|Core" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

# 5. Recommendations
echo "5. RECOMMENDATIONS" >> "$REPORT_FILE"
echo "==================" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

# Check for common issues
if systemd-analyze time 2>&1 | grep -q "min"; then
    echo "⚠️  SLOW BOOT DETECTED" >> "$REPORT_FILE"
    echo "   Consider disabling unnecessary services:" >> "$REPORT_FILE"
    systemd-analyze blame 2>&1 | grep "min\|s " | head -5 >> "$REPORT_FILE"
fi

if df -h / | grep -q "100%"; then
    echo "⚠️  ROOT FILESYSTEM FULL" >> "$REPORT_FILE"
    echo "   Clean up disk space immediately" >> "$REPORT_FILE"
fi

if journalctl -b -p err 2>&1 | grep -q "error"; then
    ERROR_COUNT=$(journalctl -b -p err 2>&1 | grep -c "error")
    echo "⚠️  BOOT ERRORS DETECTED: $ERROR_COUNT errors" >> "$REPORT_FILE"
    echo "   Check journalctl -b -p err for details" >> "$REPORT_FILE"
fi

echo "" >> "$REPORT_FILE"
echo "Diagnostics saved to: $REPORT_FILE" >> "$REPORT_FILE"
echo "Use 'cat $REPORT_FILE | less' to view report" >> "$REPORT_FILE"

echo "Boot diagnostics completed. Report: $REPORT_FILE"

2. Performance Issues Troubleshooting

Symptom Likely Cause Diagnostic Commands Solutions High CPU Usage Runaway process, inefficient code, malware top, htop, pidstat, perf Kill process, optimize code, update software High Memory Usage Memory leak, insufficient RAM, swap thrashing free, vmstat, slabtop, ps aux Restart service, add RAM, optimize memory Slow Disk I/O Disk failure, high load, filesystem issues iostat, iotop, dmesg, smartctl Replace disk, optimize queries, add cache Network Bottlenecks Bandwidth saturation, misconfiguration, hardware iftop, nethogs, netstat, ss Upgrade bandwidth, optimize traffic, fix config Slow Application Response Database issues, code bugs, dependencies strace, lsof, perf, application logs Optimize queries, fix bugs, update dependencies

Performance Diagnostic Commands

# CPU Diagnostics

top -b -n 1 # Batch mode for scripts

htop # Interactive process viewer

mpstat -P ALL # Per-CPU statistics

pidstat 1 5 # Process CPU stats

perf top # CPU profiling

uptime # Load averages

# Memory Diagnostics

free -h # Memory usage

vmstat 1 5 # Virtual memory stats

slabtop # Kernel slab cache info

ps aux --sort=-%mem # Processes by memory

cat /proc/meminfo # Detailed memory info

# Disk I/O Diagnostics

iostat -x 1 5 # Extended disk stats

iotop -o # I/O by process

df -h # Disk space

du -sh /* # Directory sizes

smartctl -a /dev/sda # Disk health

# Network Diagnostics

iftop -n # Bandwidth by connection

nethogs # Bandwidth by process

ss -tunap # Socket statistics

netstat -i # Interface statistics

ping -c 5 google.com # Network connectivity

# Application Diagnostics

strace -p PID # System calls tracing

lsof -p PID # Open files by process

tcpdump -i eth0 port 80 # Network packet capture

gdb -p PID # Debug running process

Performance Troubleshooting Script

#!/bin/bash
# performance-troubleshooter.sh
# Comprehensive performance diagnostics

REPORT_FILE="/tmp/performance-diagnostics-$(date +%Y%m%d_%H%M%S).txt"
ALERT_THRESHOLDS=(
    "CPU_LOAD=4.0"
    "MEMORY_PERCENT=90"
    "DISK_PERCENT=85"
    "SWAP_PERCENT=50"
)

echo "=== Performance Troubleshooting Diagnostics ===" > "$REPORT_FILE"
echo "Generated: $(date)" >> "$REPORT_FILE"
echo "Hostname: $(hostname)" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

# 1. System Overview
echo "1. SYSTEM OVERVIEW" >> "$REPORT_FILE"
echo "==================" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Uptime and load averages:" >> "$REPORT_FILE"
uptime >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "CPU information:" >> "$REPORT_FILE"
lscpu | grep -E "Model name|CPU\(s\)|Thread|Core|MHz" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

# 2. CPU Analysis
echo "2. CPU ANALYSIS" >> "$REPORT_FILE"
echo "===============" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Current CPU usage:" >> "$REPORT_FILE"
top -b -n 1 | grep "^%Cpu" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Load averages (1, 5, 15 min):" >> "$REPORT_FILE"
cat /proc/loadavg >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Top 5 CPU processes:" >> "$REPORT_FILE"
ps aux --sort=-%cpu | head -6 >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

# 3. Memory Analysis
echo "3. MEMORY ANALYSIS" >> "$REPORT_FILE"
echo "==================" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Memory usage:" >> "$REPORT_FILE"
free -h >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Memory pressure:" >> "$REPORT_FILE"
vmstat 1 3 >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Top 5 memory processes:" >> "$REPORT_FILE"
ps aux --sort=-%mem | head -6 >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

# 4. Disk Analysis
echo "4. DISK ANALYSIS" >> "$REPORT_FILE"
echo "================" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Disk space:" >> "$REPORT_FILE"
df -h >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "I/O statistics:" >> "$REPORT_FILE"
iostat -x 1 2 | tail -10 >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Large directories (top 10):" >> "$REPORT_FILE"
du -sh /* 2>/dev/null | sort -hr | head -10 >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

# 5. Network Analysis
echo "5. NETWORK ANALYSIS" >> "$REPORT_FILE"
echo "===================" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Network interfaces:" >> "$REPORT_FILE"
ip addr show | grep -E "^[0-9]|inet " >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

echo "Active connections:" >> "$REPORT_FILE"
ss -tun | head -20 >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

# 6. Issue Detection
echo "6. ISSUE DETECTION" >> "$REPORT_FILE"
echo "==================" >> "$REPORT_FILE"
echo "" >> "$REPORT_FILE"

ALERTS=()

# Check CPU load
LOAD1=$(uptime | awk -F'load average:' '{print $2}' | cut -d, -f1 | xargs)
CPU_CORES=$(nproc)
if (( $(echo "$LOAD1 > $CPU_CORES * 1.5" | bc -l) )); then
    ALERTS+=("⚠️  HIGH CPU LOAD: $LOAD1 (cores: $CPU_CORES)")
fi

# Check memory
MEM_PERCENT=$(free | grep Mem | awk '{print $3/$2 * 100.0}')
if (( $(echo "$MEM_PERCENT > 90" | bc -l) )); then
    ALERTS+=("⚠️  HIGH MEMORY USAGE: ${MEM_PERCENT}%")
fi

# Check disk space
ROOT_USAGE=$(df -h / | awk 'NR==2 {print $5}' | sed 's/%//')
if [ "$ROOT_USAGE" -ge 85 ]; then
    ALERTS+=("⚠️  HIGH DISK USAGE: ${ROOT_USAGE}% on /")
fi

# Report alerts
if [ ${#ALERTS[@]} -eq 0 ]; then
    echo "✅ No critical performance issues detected" >> "$REPORT_FILE"
else
    echo "ISSUES DETECTED:" >> "$REPORT_FILE"
    for alert in "${ALERTS[@]}"; do
        echo "  $alert" >> "$REPORT_FILE"
    done
    echo "" >> "$REPORT_FILE"
    echo "RECOMMENDATIONS:" >> "$REPORT_FILE"
    echo "  1. Check top processes for resource hogs" >> "$REPORT_FILE"
    echo "  2. Monitor system logs for errors" >> "$REPORT_FILE"
    echo "  3. Consider adding resources if issues persist" >> "$REPORT_FILE"
fi

echo "" >> "$REPORT_FILE"
echo "Diagnostics saved to: $REPORT_FILE" >> "$REPORT_FILE"

echo "Performance diagnostics completed. Report: $REPORT_FILE"

3. Common Performance Problems & Solutions

🔥

CPU at 100%

System slow, fans running high

Identify process: top or htop

Check if process is stuck: strace -p PID

Check for zombies: ps aux | grep Z

Kill if necessary: kill -9 PID

Prevent recurrence (update/config)

💧

Memory Leak

Memory usage grows over time

Monitor memory: watch free -h

Find leaking process: ps aux --sort=-%mem

Check process memory: pmap PID

Restart service temporarily

Update/ patch application

💾

Disk I/O Wait

System slow, high iowait

Check iowait: iostat -x 1 5

Identify I/O process: iotop -o

Check disk health: smartctl -a /dev/sda

Optimize queries/operations

Consider SSD upgrade

Quick Fix Commands for Common Issues

# Fix high CPU - find and kill process

ps aux --sort=-%cpu | head -5 # Find culprit

kill -9 PID # Force kill

renice -n 19 -p PID # Lower priority

# Fix high memory

sync; echo 3 > /proc/sys/vm/drop_caches # Clear cache

swapoff -a && swapon -a # Reset swap

systemctl restart service # Restart leaky service

# Fix disk full

find /var/log -name "*.log" -size +100M # Find large logs

journalctl --vacuum-size=500M # Clean journal

apt-get clean # Clean package cache

rm -rf /tmp/* # Clear temp files

# Fix network issues

systemctl restart network # Restart network

iptables -F # Flush firewall (careful!)

dhclient -r && dhclient # Renew DHCP

4. Advanced Troubleshooting Techniques

Process Tracing and Debugging

# Trace system calls of a process
strace -p PID                    # Attach to running process
strace -f command               # Trace child processes
strace -e trace=file command    # Trace only file operations
strace -c command               # Count system calls

# Trace library calls
ltrace -p PID                   # Library call tracing
ltrace -c command               # Count library calls

# Check open files and connections
lsof -p PID                     # Files opened by process
lsof -i :80                     # Processes using port 80
lsof -u username                # Files opened by user

# Debug with gdb
gdb -p PID                      # Attach debugger to process
gdb --args program args         # Debug from start

# Memory analysis
valgrind --leak-check=full program   # Memory leak detection
valgrind --tool=callgrind program    # Call profiling

Kernel and System Analysis

# Kernel parameters
sysctl -a                       # View all kernel parameters
sysctl -w parameter=value       # Change parameter temporarily

# Interrupts and IRQs
cat /proc/interrupts            # View interrupt distribution
mpstat -I ALL 1 5               # Interrupt statistics

# Scheduler and process info
chrt -p PID                     # View process scheduling policy
taskset -p PID                  # View CPU affinity
taskset -pc 0,2 PID             # Set CPU affinity (cores 0,2)

# Power management
cpupower frequency-info         # CPU frequency information
cpupower frequency-set -g performance  # Set performance mode

# Hardware errors
dmesg | grep -i error           # Kernel errors
journalctl -k -p err            # Kernel errors from journal
mcelog                          # Machine Check Exceptions (hardware)

5. Preventive Maintenance Script

#!/bin/bash
# preventive-maintenance.sh
# Regular system maintenance to prevent issues

LOG_FILE="/var/log/maintenance.log"
THRESHOLD_DISK=80
THRESHOLD_INODE=80
THRESHOLD_LOAD=4.0

echo "=== Preventive Maintenance - $(date) ===" | tee -a "$LOG_FILE"

# 1. Disk Space Check
echo "" | tee -a "$LOG_FILE"
echo "1. DISK SPACE CHECK" | tee -a "$LOG_FILE"
echo "===================" | tee -a "$LOG_FILE"

df -h | grep '^/dev/' | while read -r line; do
    USE_PERCENT=$(echo "$line" | awk '{print $5}' | sed 's/%//')
    MOUNT=$(echo "$line" | awk '{print $6}')
    
    if [ "$USE_PERCENT" -ge "$THRESHOLD_DISK" ]; then
        echo "⚠️  High disk usage on $MOUNT: ${USE_PERCENT}%" | tee -a "$LOG_FILE"
        
        # Cleanup suggestions
        if [ "$MOUNT" == "/" ]; then
            echo "   Cleanup commands:" | tee -a "$LOG_FILE"
            echo "   - journalctl --vacuum-size=200M" | tee -a "$LOG_FILE"
            echo "   - apt-get clean (Debian/Ubuntu)" | tee -a "$LOG_FILE"
            echo "   - yum clean all (RHEL/CentOS)" | tee -a "$LOG_FILE"
            echo "   - rm -rf /tmp/*" | tee -a "$LOG_FILE"
        fi
    fi
done

# 2. Inode Check
echo "" | tee -a "$LOG_FILE"
echo "2. INODE CHECK" | tee -a "$LOG_FILE"
echo "==============" | tee -a "$LOG_FILE"

df -i | grep '^/dev/' | while read -r line; do
    INODE_PERCENT=$(echo "$line" | awk '{print $5}' | sed 's/%//')
    MOUNT=$(echo "$line" | awk '{print $6}')
    
    if [ "$INODE_PERCENT" -ge "$THRESHOLD_INODE" ]; then
        echo "⚠️  High inode usage on $MOUNT: ${INODE_PERCENT}%" | tee -a "$LOG_FILE"
        echo "   Check for many small files:" | tee -a "$LOG_FILE"
        echo "   - find $MOUNT -type f | wc -l" | tee -a "$LOG_FILE"
    fi
done

# 3. Load Average Check
echo "" | tee -a "$LOG_FILE"
echo "3. LOAD AVERAGE CHECK" | tee -a "$LOG_FILE"
echo "====================" | tee -a "$LOG_FILE"

LOAD1=$(uptime | awk -F'load average:' '{print $2}' | cut -d, -f1 | xargs)
CPU_CORES=$(nproc)

echo "Load: $LOAD1, Cores: $CPU_CORES" | tee -a "$LOG_FILE"

if (( $(echo "$LOAD1 > $THRESHOLD_LOAD" | bc -l) )); then
    echo "⚠️  High load average: $LOAD1" | tee -a "$LOG_FILE"
    echo "   Top CPU processes:" | tee -a "$LOG_FILE"
    ps aux --sort=-%cpu | head -5 | tee -a "$LOG_FILE"
fi

# 4. Memory Check
echo "" | tee -a "$LOG_FILE"
echo "4. MEMORY CHECK" | tee -a "$LOG_FILE"
echo "===============" | tee -a "$LOG_FILE"

free -h | tee -a "$LOG_FILE"

SWAP_USAGE=$(free | grep Swap | awk '{if ($2 == 0) print 0; else print $3/$2 * 100.0}')
if (( $(echo "$SWAP_USAGE > 50" | bc -l) )); then
    echo "⚠️  High swap usage: ${SWAP_USAGE}%" | tee -a "$LOG_FILE"
fi

# 5. Service Status Check
echo "" | tee -a "$LOG_FILE"
echo "5. SERVICE STATUS CHECK" | tee -a "$LOG_FILE"
echo "======================" | tee -a "$LOG_FILE"

SERVICES=("ssh" "nginx" "mysql" "docker" "cron")
for service in "${SERVICES[@]}"; do
    if systemctl is-active --quiet "$service"; then
        echo "✅ $service: RUNNING" | tee -a "$LOG_FILE"
    else
        echo "❌ $service: STOPPED" | tee -a "$LOG_FILE"
    fi
done

# 6. Log Rotation Check
echo "" | tee -a "$LOG_FILE"
echo "6. LOG ROTATION CHECK" | tee -a "$LOG_FILE"
echo "====================" | tee -a "$LOG_FILE"

logrotate -d /etc/logrotate.conf 2>&1 | grep -i "error\|warning" | tee -a "$LOG_FILE"
if [ $? -eq 0 ]; then
    echo "⚠️  Logrotate configuration issues detected" | tee -a "$LOG_FILE"
else
    echo "✅ Logrotate configuration OK" | tee -a "$LOG_FILE"
fi

echo "" | tee -a "$LOG_FILE"
echo "Maintenance check completed at $(date)" | tee -a "$LOG_FILE"
echo "Full log: $LOG_FILE" | tee -a "$LOG_FILE"

Troubleshooting Best Practices Checklist

Always check logs first: journalctl -xb
Monitor resource usage before making changes
Reproduce the issue to understand it better
Make one change at a time and test
Document everything you try
Have a backup/rollback plan
Use version control for configuration files
Test in staging before production
Monitor after fixing to ensure issue is resolved
Create runbooks for common issues

Critical Safety Tips:
1. Backup before major changes: Always have a recovery plan
2. Test commands in dry-run mode: Use --dry-run when available
3. Don't run unknown commands: Understand what a command does first
4. Use maintenance windows: Schedule disruptive changes appropriately
5. Monitor after changes: Ensure fixes don't break other things
6. Document resolutions: Create knowledge base articles
7. Set up monitoring: Prevent issues before they occur

Getting Started with Troubleshooting

Follow this systematic approach to become an effective troubleshooter:

Learn basic commands: Master top, htop, iostat, vmstat, journalctl
Understand normal behavior: Monitor your systems when they're healthy
Start with logs: Always check logs first when issues occur
Practice on test systems: Create test environments to learn
Follow the OSI model: Start physical, move up to application
Use the scripts in this guide: Automate common diagnostics
Document everything: Create your own troubleshooting guide
Learn from incidents: Conduct post-mortems for major issues
Share knowledge: Teach others what you've learned
Stay curious: Keep learning new tools and techniques

Master the Art of Linux Troubleshooting

Effective troubleshooting is both an art and a science. By following systematic approaches and using the right tools, you can solve even the most complex performance and boot issues. Remember that every problem you solve makes you a better administrator.

Remember: The best troubleshooters are not those who know all the answers, but those who know how to find them. Develop your diagnostic skills, build your toolkit, and approach problems methodically.

Next Steps: Practice the scripts in this guide on a test system. Create your own troubleshooting checklist. The next time an issue occurs, you'll be prepared to diagnose and resolve it quickly and effectively.

Troubleshooting Performance & Boot Issues: Complete Guide