Which of the following tools are used to measure disk I/O? (Select THREE correct Answers.)

A.
lpstat

B.
sar

C.
iostat

D.
vmstat

E.
mpstat

Explanation:
The primary tool to use in troubleshooting disk I/O problems is iostat.
sar -d provides useful historical context. vmstat can provide information about disk saturation. For
Solaris 10 systems, dtrace can provide extremely fine-grained information about I/O performance
and what is causing any utilization or saturation problems. The DTrace Toolkit provides a number of
ready-to-use scripts to take advantage of DTrace’s capabilities.
UNIX man pages vmstat () vmstat reports information about processes, memory, paging, block IO,
traps, and cpu activity. The first report produced gives averages since the last reboot. Additional
reports give information on a sampling period of length delay. The process and memory reports are
instantaneous in either case.
UNIX man pages iostat (8)
The iostat utility displays kernel I/O statistics on terminal, device and cpu operations. The first
statistics that are printed are averaged over the system uptime. To get information about the
current activity, a suitable wait time should be specified, so that the subsequent sets of printed
statistics will be averaged over that time.
UNIX man pages sar (1)
In the first instance, sar samples cumulative activity counters in the operating system at n intervals
of t seconds, where t should be 5 or greater. If t is specified with more than one option, all headers
are printed together and the output may be difficult to read. (If the sampling interval is less than 5,
the activity of sar itself may affect the sample.) If the -o option is specified, it saves the samples in
filename in binary format. The default value of n is 1.

UNIX man pages mpstat (1M)
mpstat reports processor statistics in tabular form. Each row of the table represents the activity of
one processor. The first table summarizes all activity since boot; each subsequent table summarizes
activity for the preceding interval. All values are rates (events per second) unless otherwise noted.
UNIX man pages lpstat (1)
lpstat displays status information about the current classes, jobs, and printers. When run with no
arguments, lpstat will list jobs queued by the current user.