Hi (newbie alert) I am struggling with how to model a particular workload: - there are two groups of processes (8 writers and 8 readers), that run concurrently, writing to a single RAID unit - each of the writers - opens 36 files - appends to the files in 1M chunks until they reach 100G - closes those files and opens a new set - each of the readers - reads a group of 36 contemporaneous files from beginning to end - moves on to the next group My goal is not to maximise numbers from fio tests but rather to model the system and how it is likely to scale up or down. In particular I want to observe the system behaviour over an extended period (up to 24h) with readers & writers hammering away. Below is my initial sketch which isn't right; in my tests (with smaller filesize, numjobs, nrfiles) it runs the file layout fine but I never seem to get a prolonged period of read operations in parallel with writes. [global] direct=0 fsync=0 bs=4k size=1M ioengine=posixaio rwmixread=50 rwmixwrite=50 group_reporting=1 per_job_logs=0 filesize=100G file_append=1 invalidate=1 refill_buffers=1 [writer] name=writer readwrite=write numjobs=8 nrfiles=36 file_service_type=roundrobin [reader] name=reader readwrite=read numjobs=8 nrfiles=36 file_service_type=roundrobin Any pointers would be most welcome. Vince -- 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
