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.

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 /proc filesystem for gathering information.

Platform support

Sar was originally developed for the Unix System V operating system; it is available in AIX, HP-UX, Solaris and other System V based operating systems but it is not available for macOS or FreeBSD. Prior to 2013 there was a bsdsar tool, but it is now deprecated.

Most Linux distributions provide sar utility through the sysstat package.

Syntax

-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

Sysstat package

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

  • :Collect, report, or save system activity information.–LinuxUser CommandsManual
  • :Collect and store binary data in the system activity daily data file.–LinuxAdministration and Privileged CommandsManual
  • :shell variant ofsar, supporting the same flags assarcommand which write a daily report in the /var/log/sa directory.–LinuxAdministration and Privileged CommandsManual
  • :, similar tosarbut 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.
  • :reports basic CPU statistics and input/output statistics for devices, partitions and network filesystems.–LinuxUser CommandsManual
  • :reports individual or combined processor related statistics.–LinuxUser CommandsManual
  • :reports statistics for Linux tasks (processes): I/O, CPU, memory, etc.–LinuxUser CommandsManual
  • :reports input/output statistics for network filesystems (NFS).–LinuxUser CommandsManual
  • :reports I/O statistics forCIFSresources.–LinuxUser CommandsManual

See also

  • atopsar
  • Nmon
  • sag - "system activity graph" command
  • 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

Footnotes