sar (Unix)

System Activity Report (sar) is a Unix System V-derived system monitor command used to report on various system loads, including CPU activity, memory/paging, interrupts, device load, network and swap space utilization. Sar uses /procfilesystem for gathering information [3]

sar

Stable release	sysstat 12.1.1[1] / October 13, 2018 (2018-10-13)
Preview release	sysstat 11.7.4 / June 1, 2018 (2018-06-01) [2]
Repository	github.com/sysstat/sysstat/
Written in	C
Operating system	AIX, Linux, Solaris, HP-UX
Type	System reporting
Website	sebastien.godard.pagesperso-orange.fr//

Called regularly by cron, sadc does the monitoring and stores its measurements to files in the /var/log/sa/ folder. The sar client can be used to explore this data.

Platform support

Sar was originally developed for Solaris operating system[4] and it is available in Linux, Solaris, AIX, HP-UX, but it is not available for macOS or FreeBSD, until 2013 there was a bsdsar tool actually deprecated [5].

Linux distributions, such as Debian, Red Hat Enterprise Linux, SuSe[6] and Ubuntu provide sar utility through the sysstat package.

Syntax

sar [-flags] [ -e time ] [ -f filename ] [-i sec ] [ -s time ]

-f

filename Uses filename as the data source for sar. The default is the current daily data file /var/adm/sa/sadd.

-e

time Selects data up to time. The default is 18:00.

-i

sec Selects data at intervals as close as possible to sec seconds.

Example

[user@localhost]$ sar  # Displays current CPU activity.

Sysstat package

Additional to sar command, Linux sysstat package in Debian[7], RedHat Enterprise Linux and SuSE provides additional reporting tools:

• sar(1): Collect, report, or save system activity information. – Linux User Commands Manual
• sa1(8): Collect and store binary data in the system activity daily data file. – Linux Administration and Privileged Commands Manual
• sa2(8): shell variant of sar, supporting the same flags as sar command which write a daily report in the /var/log/sa directory. – Linux Administration and Privileged Commands Manual
• sadf(1): , similar to sar but can write its data in different formats (CSV, XML, etc.). This is useful to load performance data into a database, or import them in a spreadsheet to make graphs.
• iostat(1): reports basic CPU statistics and input/output statistics for devices, partitions and network filesystems. – Linux User Commands Manual
• mpstat(1): reports individual or combined processor related statistics. – Linux User Commands Manual
• pidstat(1): reports statistics for Linux tasks (processes) : I/O, CPU, memory, etc. – Linux User Commands Manual
• nfsiostat(1): reports input/output statistics for network filesystems (NFS). – Linux User Commands Manual
• cifsiostat(1): reports I/O statistics for CIFS resources. – Linux User Commands Manual

See also

• atopsar
• Nmon
• sag - "system activity graph" command[8]
• ksar- BSD licensed Java-based application to create graph of all parameters from the data collected by Unix sar utilities.
• CURT, IBM AIX CPU Usage Reporting Tool

• isag, tcl based command to plot sar/sysstat data

References

• sar(1) – Solaris 10 User Commands Reference Manual
• Easy system monitoring with SAR (IBM developerWorks)
• System Activity Reporter (Softpanorama)
• Article on sar at Computerhope

Footnotes

1. https://github.com/sysstat/sysstat/releases/tag/v12.1.1
2. http://sebastien.godard.pagesperso-orange.fr/
3. http://sebastien.godard.pagesperso-orange.fr/man_sar.html
4. https://www.itworld.com/article/2786092/open-source-tools/unix-tip--using-sar-for-long-term-performance-analysis.html
5. https://www.freshports.org/sysutils/bsdsar
6. http://www.softpanorama.org/Admin/Monitoring/sar.shtml
7. https://packages.debian.org/sid/sysstat
8. "sag(1)" (PDF). SUNOS Reference Manual. Mountain View, California: Sun Microsystems. 1993-02-24. pp. 1–895. Retrieved 2010-05-04. sag - system activity graph [...] DESCRIPTION sag graphically displays the system activity data stored in a binary data file by a previous sar(1) run.