On Wed, Jan 7, 2015 at 5:32 PM, Jens Axboe <axboe@xxxxxxxxx> wrote: > An example job file would contain: > > random_distribution=zipf > random_drift=gradual > random_drift_start_percentage=50 > random_drift_percentage=10 Jens, This is an interesting proposal. Just to make sure if I understand your example correctly, in this example you are proposing Gradual shift in hot/cold Blocks after 50% of workload is generated. This shift then would be 10% total distribution for every 10% of remaining workload access. It that correct ? If I understand this correctly, the workload randomness distribution would change after drift. For example if I start with zipf:1.2 initially, I would have different distribution after the drift which is hard to describe. Would it be still Zipf with what theta parameter ? Having said that, It would be more interesting and practical if we can set specific distribution parameter for the drifted workload phases. For example, Would be nice to divide the workload into 4 phases, phase 1: workload start with zipf:1.2, phase 2: workload drift to zipf:1.4, phase 3: workload drift to pareto, phase 4:workload drift to uniform distribution. With this approach, we have more control on the workload randomness distribution parameters for each gradual drift. Moreover, it would be more practical to characterize a real workload and extract distribution parameters for these phases and then feed them to fio for synthetic re-generation of such a workload. Hope it helps. -- Alireza -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
