I am trying to find the bottleneck of a server running a fairly busy php/mysql site. My first culprit was io but iostat shows that on average iowait consumes only %3.60 of cpu time. here is the complete result of issuing iostat:
avg-cpu: %user %nice %system %iowait %steal %idle 65.78 0.00 8.52 3.60 0.00 22.10 Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn sda 42.36 138.28 1754.70 408630278 5185216128
So I am wondering if the iowait is within acceptable range, and if not, whether switching from SATA to SSD would dramatically reduce it?