sysstat est une collection d’outils de surveillance des performances pour Linux comprenant sar, iostat, mpstat, pidstat et cifsiostat. Ces outils collectent, rapportent et archivent les données d’activité du système pour l’analyse en temps réel et la revue historique des performances.
Installation
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
Activer la collecte de données
# 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 — Rapporteur d’activité système
Utilisation CPU
# 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
Utilisation mémoire
# 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
E/S disque
# 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
Réseau
# 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
Autres métriques
# 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 — Statistiques d’E/S
# 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
Colonnes clés d’iostat
# 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 — Statistiques multiprocesseur
# 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 — Statistiques par processus
# 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 — Statistiques d’E/S CIFS
# 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
Collecte de données (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
Analyse historique
# 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
Référence rapide
| Outil | Fonction |
|---|
sar | Rapporteur d’activité système (CPU, mémoire, disque, réseau) |
iostat | Statistiques d’E/S disque |
mpstat | Statistiques par CPU |
pidstat | Statistiques par processus |
cifsiostat | E/S du système de fichiers CIFS |
sadc | Collecteur de données d’activité système (backend) |
sa1 | Wrapper cron pour sadc |
sa2 | Générateur de rapports quotidiens |
sadf | Convertisseur de format de données (CSV, JSON, SVG) |
| sar Flag | Métrique |
|---|
-u | Utilisation du CPU |
-r | Utilisation de la mémoire |
-S | Utilisation du swap |
-d | E/S disque |
-n DEV | Interfaces réseau |
-n TCP | Statistiques TCP |
-w | Changements de contexte |
-q | File d’exécution / charge moyenne |
-B | Statistiques de pagination |
-b | Taux de transfert d’E/S |
-F | Utilisation du système de fichiers |
