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sysstat 명령어

sysstat는 sar, iostat, mpstat, pidstat 및 cifsiostat을 포함하는 Linux 성능 모니터링 도구 모음입니다. 이러한 도구들은 실시간 분석과 과거 성능 검토를 위해 시스템 활동 데이터를 수집, 보고 및 보관합니다.

설치

Linux/Ubuntu

# Ubuntu/Debian
sudo apt install sysstat

# Enable automatic data collection
sudo systemctl enable sysstat
sudo systemctl start sysstat

# Fedora/RHEL
sudo dnf install sysstat
sudo systemctl enable --now sysstat

# Arch Linux
sudo pacman -S sysstat

# Verify installation
sar -V

데이터 수집 활성화

# Edit sysstat config to enable collection
sudo vi /etc/default/sysstat
# Set ENABLED="true"

# Configure collection interval (default: every 10 minutes)
# Collection is handled by /etc/cron.d/sysstat or systemd timers
# Data is stored in /var/log/sysstat/ (or /var/log/sa/)

# Manually trigger a data collection
sudo /usr/lib/sysstat/sa1 1 1

sar — 시스템 활동 리포터

CPU 사용량

# Current CPU usage (1 second interval, 5 samples)
sar -u 1 5

# CPU usage with ALL fields
sar -u ALL 1 5

# Per-CPU breakdown
sar -P ALL 1 5

# Specific CPU core
sar -P 0 1 5

# CPU usage from today's historical data
sar -u

# CPU usage from a specific day's archive
sar -u -f /var/log/sysstat/sa21

# CPU usage between specific times
sar -u -s 09:00:00 -e 17:00:00

# CPU usage from a specific date file
sar -u -f /var/log/sysstat/sa15 -s 14:00:00 -e 15:00:00

메모리 사용량

# Memory utilization
sar -r 1 5

# Memory with ALL fields
sar -r ALL 1 5

# Swap usage
sar -S 1 5

# Huge pages usage
sar -H 1 5

# Historical memory data
sar -r -f /var/log/sysstat/sa21

디스크 I/O

# Disk I/O activity
sar -d 1 5

# Disk I/O with device names (not dev major/minor)
sar -d -p 1 5

# Block device utilization
sar -b 1 5

# Specific device only
sar -d --dev=sda 1 5

# Historical disk data
sar -d -p -f /var/log/sysstat/sa21

네트워크

# Network interface statistics
sar -n DEV 1 5

# Network errors
sar -n EDEV 1 5

# TCP statistics
sar -n TCP 1 5

# TCP errors
sar -n ETCP 1 5

# Socket statistics
sar -n SOCK 1 5

# All network stats combined
sar -n ALL 1 5

# NFS client statistics
sar -n NFS 1 5

# NFS server statistics
sar -n NFSD 1 5

# IP-level statistics
sar -n IP 1 5

# ICMP statistics
sar -n ICMP 1 5

기타 메트릭

# Context switches and interrupts
sar -w 1 5

# Run queue and load average
sar -q 1 5

# Process creation rate
sar -c 1 5

# Paging statistics
sar -B 1 5

# I/O transfer rates
sar -b 1 5

# File systems utilization
sar -F 1 5

# TTY device activity
sar -y 1 5

# Power management
sar -m CPU 1 5

iostat — I/O 통계

# Basic I/O stats
iostat

# Extended statistics with human-readable units
iostat -xh 1 5

# Extended statistics for all devices
iostat -x 1 5

# Show only specific device
iostat -x sda 1 5

# Include NFS mount statistics
iostat -n

# Show megabytes instead of kilobytes
iostat -m 1 5

# Show partition statistics
iostat -p sda 1 5

# Continuous monitoring every 2 seconds
iostat -x 2

# JSON output
iostat -x -o JSON 1 5

# Omit first (since boot) report
iostat -x -y 1 5

주요 iostat 컬럼

# r/s      — Read requests per second
# w/s      — Write requests per second
# rMB/s    — Megabytes read per second
# wMB/s    — Megabytes written per second
# rrqm/s   — Read requests merged per second
# wrqm/s   — Write requests merged per second
# r_await  — Average read request latency (ms)
# w_await  — Average write request latency (ms)
# aqu-sz   — Average queue size
# rareq-sz — Average read request size (KB)
# wareq-sz — Average write request size (KB)
# %util    — Percentage of time device was busy

mpstat — 멀티프로세서 통계

# All CPUs summary
mpstat 1 5

# Per-CPU breakdown
mpstat -P ALL 1 5

# Specific CPU cores
mpstat -P 0,1,2,3 1 5

# Include interrupt statistics
mpstat -I ALL 1 5

# Show only specific interrupt types
mpstat -I CPU 1 5
mpstat -I SCPU 1 5
mpstat -I SUM 1 5

# JSON output
mpstat -P ALL -o JSON 1 5

# Node-level stats (NUMA)
mpstat -N ALL 1 5

pidstat — 프로세스 통계

# CPU usage per process
pidstat 1 5

# Memory usage per process
pidstat -r 1 5

# Disk I/O per process
pidstat -d 1 5

# Context switches per process
pidstat -w 1 5

# Threads (show individual threads)
pidstat -t 1 5

# Specific PID
pidstat -p 1234 1 5

# All stats for a specific process
pidstat -u -r -d -w -p 1234 1 5

# Filter by process name
pidstat -C "nginx" 1 5

# Show child process statistics
pidstat -l 1 5

# Stack usage per process
pidstat -s 1 5

# Combined CPU + Memory + I/O for a process
pidstat -urd -p 1234 1 5

cifsiostat — CIFS I/O 통계

# CIFS filesystem I/O stats
cifsiostat 1 5

# Show in megabytes
cifsiostat -m 1 5

# Include timestamps
cifsiostat -t 1 5

# Skip first (since-boot) report
cifsiostat -y 1 5

데이터 수집 (sadc/sa1/sa2)

# sadc — System Activity Data Collector (backend)
# Typically called by cron or systemd timers

# Manual data collection (1 sample per second, 10 samples)
sudo /usr/lib/sysstat/sadc 1 10 /var/log/sysstat/sa$(date +%d)

# sa1 — Wrapper for sadc, used in cron
# Collects 1 sample:
sudo /usr/lib/sysstat/sa1 1 1

# sa2 — Generate daily summary report
# Creates sar files from binary data:
sudo /usr/lib/sysstat/sa2 -A

# Typical cron entries (/etc/cron.d/sysstat):
# Collect data every 10 minutes
# */10 * * * * root /usr/lib/sysstat/sa1 1 1
# Generate daily summary at 23:53
# 53 23 * * * root /usr/lib/sysstat/sa2 -A

히스토리 분석

# List available data files
ls -la /var/log/sysstat/

# Read data from a specific day (e.g., the 15th)
sar -u -f /var/log/sysstat/sa15

# Read data for a specific time window
sar -u -f /var/log/sysstat/sa15 -s 08:00:00 -e 12:00:00

# Export historical data as CSV
sadf -d /var/log/sysstat/sa15 -- -u > cpu_history.csv

# Export as JSON
sadf -j /var/log/sysstat/sa15 -- -u > cpu_history.json

# Export as SVG graph
sadf -g /var/log/sysstat/sa15 -- -u > cpu_graph.svg

# Compare data across days
for day in 15 16 17 18 19; do
  echo "=== Day $day ==="
  sar -u -f /var/log/sysstat/sa$day | tail -1
done

빠른 참조

ToolPurpose
sarSystem activity reporter (CPU, memory, disk, network)
iostatDisk I/O statistics
mpstatPer-CPU statistics
pidstatPer-process statistics
cifsiostatCIFS filesystem I/O
sadcSystem activity data collector (backend)
sa1Cron wrapper for sadc
sa2Daily report generator
sadfData format converter (CSV, JSON, SVG)
sar FlagMetric
-uCPU utilization
-rMemory utilization
-SSwap utilization
-dDisk I/O
-n DEVNetwork interfaces
-n TCPTCP statistics
-wContext switches
-qRun queue / load average
-BPaging statistics
-bI/O transfer rates
-FFilesystem utilization