CPU usage with iostat
Bruno Galindro da Costa
bruno.galindro at gmail.com
Fri Nov 26 12:47:06 UTC 2010
Hi,
Why the first execution of "iostat -c" always displays the same values?
[root at abc ~]# iostat -c
Linux 2.6.9-55.ELsmp (abc) 11/26/2010
avg-cpu: %user %nice %sys %iowait %idle
5.62 0.00 3.08 3.30 88.00
[root at abc ~]# iostat -c
Linux 2.6.9-55.ELsmp (abc) 11/26/2010
avg-cpu: %user %nice %sys %iowait %idle
5.62 0.00 3.08 3.30 88.00
[root at abc ~]# iostat -c
Linux 2.6.9-55.ELsmp (abc) 11/26/2010
avg-cpu: %user %nice %sys %iowait %idle
5.62 0.00 3.08 3.30 88.00
___________________________________________________________________________________
___________________________________________________________________________________
When I use "iostat -c 1" the next values are modified:
[root at abc ~]# iostat -c 1
Linux 2.6.9-55.ELsmp (abc) 11/26/2010
avg-cpu: %user %nice %sys %iowait %idle
5.62 0.00 3.08 3.30 88.00
avg-cpu: %user %nice %sys %iowait %idle
2.00 0.00 4.00 23.25 70.75
avg-cpu: %user %nice %sys %iowait %idle
0.75 0.00 1.74 24.38 73.13
avg-cpu: %user %nice %sys %iowait %idle
0.25 0.00 0.50 24.56 74.69
___________________________________________________________________________________
___________________________________________________________________________________
Reading the man pages os iostat, I could not understand these lines:
*"The first report generated by the iostat command provides statistics
concerning the time since the system was booted. Each subsequent report
covers the time since the previous report."
"The first report contains statistics for the time since system startup
(boot). Each subsequent report contains statistics collected during the
interval since the previous report."*
*Why it can´t build a report with the current usage values at the first
execution?*
--
Att.
Bruno Galindro da Costa
bruno.galindro at gmail.com
http://www.thevenusproject.com/
http://www.arthurvinicius.com.br/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.fedoraproject.org/pipermail/users/attachments/20101126/be7d7c03/attachment.html
More information about the users
mailing list