Using historical data

Red Hat Enterprise Linux 9.2 LPAR mode z/VM guest KVM guest

Historical data is available for the keyword time and the sets of keywords cpustat.<name>, meminfo.<name>, and vmstat.<name>.

See Keywords for CPU hotplug rules and Keywords for memory hotplug rules for details about these keywords.

Use the suffixes [<n>] to retrieve the data of <n> intervals in the past, where <n> can be in the range 0 - 100.

Examples

cpustat.idle
yields the current value for the counted idle ticks.
cpustat.idle[1]
yields the idle ticks as counted one interval ago.
cpustat.idle[5]
yields the idle ticks as counted five intervals ago.
cpustat.idle - cpustat.idle[5]
yields the idle ticks during the past five intervals.
time - time[1]
yields the length of an update interval in seconds.
cpustat.total_ticks - cpustat.total_ticks[5]
yields the total number of ticks during the past five intervals.
(cpustat.idle - cpustat.idle[5]) / (cpustat.total_ticks - cpustat.total_ticks[5])
yields the average ratio of idle ticks to total ticks during the past five intervals.

Multiplying this ratio with 100 yields the percentage of idle ticks during the last five intervals.

Multiplying this ratio with 100 * onumcpus yields the accumulated percentage of idle ticks for all processors during the last five intervals.