no IO wait with fusion io

https://access.redhat.com/sites/default/files/fusion_iodrives_on_rhel_6_for_database_performance_acceleration_0.pdf


Examining the I/O and cpu utilization in the vmstat output during the Fibre Channel run, the
I/O is highlighted with the yellow block while the CPU utilization is highlighted in blue. The
“bo” column (blocks out) in yellow shows peak write rates of 150 MB/s to the Fibre Channel
storage. As the peak rates are achieved, the CPU utilization block shows I/O waits under the
“wa” column and consequently resulting in “id”  (idle) times when cpus spin in user space.

Comparing the vmstat output from both runs, the Fusion ioDrives write throughput peaks at
400-500 MB/s. However in this case, the I/O is not the limiting factor. Examining the CPU
utilization block in the Fusion ioDrives vmstat output, there are no I/O waits in the “wa”column and very little idle time in the “id” column so the system is running at its full potential.
Using Fusion ioDrives in this situation helped remove the I/O bottleneck presented by the
fibre channel storage and allowed the application to fully utilize the processing power of the
server.