System information

System Monitoring Utilities 17
2.2 System Information
2.2.1 Device Load Information: iostat
iostat monitors the system device loading. It generates reports that can be useful
for better balancing the load between physical disks attached to your system.
The first iostat report shows statistics collected since the system was booted. Sub-
sequent reports cover the time since the previous report.
tux@mercury:~> iostat
Linux 2.6.32.7-0.2-default (geeko@buildhost) 02/24/10 _x86_64_
avg-cpu: %user %nice %system %iowait %steal %idle
0,49 0,01 0,10 0,31 0,00 99,09
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 1,34 5,59 25,37 1459766 6629160
sda1 0,00 0,01 0,00 1519 0
sda2 0,87 5,11 17,83 1335365 4658152
sda3 0,47 0,47 7,54 122578 1971008
When invoked with the -n option, iostat adds statistics of network file systems
(NFS) load. The option -x shows extended statistics information.
You can also specify which device should be monitored at what time intervals. For ex-
ample, iostat -p sda 3 5 will display five reports at three second intervals for
device sda.
NOTE: sysstat Package
iostat is part of sysstat package. To use it, install the package with zyp-
per in sysstat
2.2.2 Processor Activity Monitoring:
mpstat
The utility mpstat examines activities of each available processor. If your system
has one processor only, the global average statistics will be reported.