Brendan Gregg of Sun Oracle fame made a good explanation how to visualize latency to get a better understanding of what is going on (and as such about how to solve bottlenecks). I have seen all this already in various posts in his blog and in the Analytics package in an OpenStorage presentation, but the ACM article summarizes it very good.
Unfortunately Analytics is AFAIK not available in OpenSolaris, so we can not go out and adapt it for FreeBSD (which would probably require to port/implement some additional dtrace stuff/probes). I am sure something like this would be very interesting to all those companies which use FreeBSD in an appliance (regardless if it is a storage appliance like NetApp, or a network appliance like a Cisco/Juniper router, or anything else which has to perform good).
