[CentOS] server is extremly slugish - unable to troubleshoot..

Mon Aug 23 09:45:06 UTC 2010
John Doe <jdmls at yahoo.com>

From: Roland RoLaNd <r_o_l_a_n_d at hotmail.com>
>At times, with no specific reason. system becomes extremly slugish.
>PS: any command that may show I/O in KB/MB on the HDD ? 

iostat / vmstat
Checked dmesg for anything out of the ordinary...?
Always at the same time?
Or at a precise time?

JD