Unlock Linux Performance Monitoring with sar: Install, Configure, Export Data

Introduction

Sar was originally implemented on the Salaris Unix system and later ported to most other Unix systems (e.g., AIX, HP‑UX). A French implementation of sysstat provides the same functionality on Linux.

It works by using cron to schedule a program that collects current system performance metrics and stores them in a binary file.

Installation

You can download the source and compile it yourself, or install a binary package; RHEL systems include it by default.

Main Features

Supported capabilities:

Collect virtually all system performance data.

Configure retention period for historical data.

Export collected data from the binary file to various formats (CSV, XML, JSON, etc.).

Graph performance data; several third‑party tools are available, and sar includes isag.

Configuration

Modify historical data retention period:

vi /etc/sysconfig/sysstat   # Red Hat
vi /etc/default/sysstat      # Debian
HISTORY=90   # keep 90 days of history

Change data collection frequency (cron schedule); default is every 10 minutes:

vi /etc/cron.d/sysstat

Export

Export performance data in various formats:

sadf -d   # CSV
sadf -x   # XML
sadf -j   # JSON

Graphing

Graphs can be generated with isag, which provides a graphical interface that is easy to use, though the visual quality is modest.

Other tools that use sysstat data for graphing:

sysstatgraph, which uses PHP and HTML5 Canvas.

Article link: http://kyle.xlau.org/posts/linux-sar.html