sar
TLDR
Report I/O statistics every second
$ sar -b 1
Report network statistics every 2 seconds, 10 times$ sar -n DEV 2 10
Report CPU utilization every 2 seconds$ sar -u ALL 2
Report memory utilization$ sar -r ALL 1 20
Report run queue and load averages$ sar -q 1
Report paging statistics$ sar -B 5
Report disk statistics$ sar -d 1
SYNOPSIS
sar [options] [interval [count]]
DESCRIPTION
sar (System Activity Reporter) collects, reports, and saves system activity information. It can report on CPU, memory, I/O, network, and other subsystem performance.
PARAMETERS
-b
Report I/O and transfer rate statistics-B
Report paging statistics-d
Report disk I/O statistics-n KEYWORD
Report network statistics (DEV, EDEV, NFS, SOCK, IP, etc.)-q
Report queue length and load averages-r [ALL]
Report memory utilization statistics-u [ALL]
Report CPU utilization-v
Report status of inode, file, and other kernel tables-w
Report task creation and system switching activity-W
Report swapping statistics-y
Report TTY devices activity-f FILE
Read data from specified file-o FILE
Write data to specified file-s TIME
Set start time for report-e TIME
Set end time for report-P {cpu|ALL}
Report per-processor statistics-j {ID|LABEL|PATH|UUID}
Display persistent device names
CAVEATS
Without interval, sar reads from system activity data files. Data is collected by the sadc daemon and stored in /var/log/sa/. Historical data requires sysstat cron jobs to be enabled.
HISTORY
sar is part of the sysstat package, originally from System V Unix. It provides comprehensive system activity reporting and historical data analysis.
