I’m always trying to find a good method of monitoring system performance and logging it, but today I ran into a rather strange issue that I couldn’t find on google.

sar 0 was returning high idle percentages:

sar -u 0
08:17:29 AM    CPU   %user   %nice  %system  %iowait   %idle
08:17:29 AM    all   18.11    0.01   11.66   70.22   3549.42
running top didn’t produce 3.5k % idle and in fact the system was nearly 98% idle. 
The quick fix is to simply run

yum update sysstat
That fixed the problem immediately on the box I was using.

Hope this helps someone else.