Sar (Unix)

System Activity Report 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  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  tool, but it is now deprecated.

Most Linux distributions provide  utility through the   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.

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