iostat(1)
NAME
iostat − report I/O statistics
SYNOPSIS
iostat [ interval [ count ] ]
DESCRIPTION
iostat iteratively reports the number of characters read and written to terminals, and, for each disk, the number of seeks transfers per second, kilobytes transfered per second, and the milliseconds per average seek. It also gives the percentage of time the system has spent idling (id), in user mode (us), in system mode (sy), waiting for I/O in wait mode (wa), and waiting for memory in sxbrk mode (sb).
To compute this information, for each disk, seeks and data transfer completions and number of words transferred are counted; for terminals collectively, the number of input and output characters are counted. Also, each sixtieth of a second, the state of each disk is examined and a tally is made if the disk is active. From these numbers and given the transfer rates of the devices it is possible to determine average seek times for each device.
The optional interval argument causes iostat to report once each interval seconds. The first report is for all time since a reboot and each subsequent report is for the last interval only. The interval value must also be an integer greater than zero.
The optional count argument restricts the number of reports. The count value must be an integer greater than zero.
FILES
/dev/kmem
/unix
SEE ALSO
CX/UX User’s Reference Manual