On 02/07/11 12:49, Yi Zhang wrote:
If buffering is on, the running time of my app doesn't reflect the actual I/O cost. My goal is to accurately measure the time of I/O. With buffering on, ZFS would batch up a bunch of writes and change both the original I/O activity and the time.
if batching main pool writes improves the overall throughput of the system over a more naive i/o scheduling model, don't you want your users to see the improvement in performance from that batching?
why not set up a steady-state sustained workload that will run for hours, and measure how long it takes the system to commit each 1000 or 10000 transactions in the middle of the steady state workload?
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