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Performance Tools: Deep Analysis

Performance tools analyze system performance. CPU. Memory. I/O. Network.

Here's the thing: Performance tools show what's slow. Use them to find bottlenecks.

CPU Analysis​

vmstat: System Statistics​

vmstat                            # Current stats
vmstat 1                          # Every second
vmstat 1 10                       # 10 times, every second

My take: vmstat shows CPU, memory, I/O. Useful overview.

mpstat: CPU Statistics​

mpstat                            # All CPUs
mpstat -P ALL                     # Per-CPU
mpstat 1                          # Every second

My take: mpstat shows CPU details. Per-CPU statistics.

Memory Analysis​

free: Memory Usage​

free -h                           # Human-readable
free -m                           # Megabytes
free -s 5                         # Every 5 seconds

My take: free shows memory. Use -h for readability.

Memory Details​

cat /proc/meminfo                 # Detailed memory info

My take: /proc/meminfo has detailed memory info. Read it.

I/O Analysis​

iostat: I/O Statistics​

# Install
sudo apt install sysstat          # Debian/Ubuntu
sudo dnf install sysstat          # RHEL/CentOS

# Use
iostat                            # Current stats
iostat 1                          # Every second
iostat -x                         # Extended stats

My take: iostat shows I/O statistics. Useful for disk performance.

Network Analysis​

ifstat: Network Statistics​

# Install
sudo apt install ifstat

# Use
ifstat                            # All interfaces
ifstat -i eth0                    # Specific interface

My take: ifstat shows network statistics. Monitor network performance.

sar: System Activity Reporter​

Install sar​

sudo apt install sysstat
sudo systemctl enable sysstat
sudo systemctl start sysstat

My take: sar collects historical data. Useful for analysis.

View sar Data​

sar                              # Today's data
sar -u                           # CPU
sar -r                           # Memory
sar -d                           # Disk
sar -n DEV                       # Network

My take: sar shows historical data. Analyze past performance.

Common Analysis Patterns​

Check CPU Bottleneck​

vmstat 1
mpstat -P ALL 1

Check Memory Pressure​

free -h
vmstat 1

Check I/O Bottleneck​

iostat -x 1
iotop

Common Mistakes (I've Made These)​

  1. Not installing tools: Install sysstat. It provides many tools.

  2. Not collecting data: sar collects data. Enable it.

  3. Only checking one metric: Check CPU, memory, I/O, network. All matter.

  4. Not understanding output: Learn what the numbers mean. They tell you things.

  5. Ignoring historical data: sar shows trends. Use it.

Real-World Examples​

Analyze Performance​

# CPU
mpstat -P ALL 1

# Memory
free -h
vmstat 1

# I/O
iostat -x 1

# Network
ifstat

What's Next?​

Now that you can analyze performance, let's talk about Troubleshooting Techniques to fix problems.

Personal note: Performance tools seemed complex at first. Then I learned them. Now I use them to find bottlenecks. They're essential. Learn them.