On Tue, Jul 02 2013, James Vanns wrote: > Hi. In attempting to get a single job to create files before allowing further jobs to perform I/O on them, I cannot > see how to restrict the sum total of all the files on the device. I wish to create n files ranging in size from i-j > with a cap of m in total (so the sum of n does not exceed m). For example; > > [file-generator] > numjobs=1 > create_only=1 > create_on_open=0 > time_based=0 > fill_fs=0 > fill_device=0 > filesize=4k-20m > size=512m > nrfiles=256 > fallocate=posix > fadvise_hint=1 > filename_format=\$filenum.dat > directory=/tmp/fio > > I'd expect the above to create 256 files ranging from 4k to 20m and a 'du -sh' on /tmp/fio to result in > 512m. However, it always seems to fill the device! How can I stop this? It might be a little confusing, but it's actually documented behaviour. If you set filesize and nrfiles, that dictates the workload size and not the size= setting. So with the above, you could expect anywhere from 4k * 256 to 20m * 256 of bytes used. For a normal random distribution of sizes, you should see around ~2.5GB of data used. -- Jens Axboe -- 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
