Mathieu Othacehe writes: >> This is still pretty bad, but better than the <1M performance suggested >> by previous runs. > > Mmh interesting, I also have a x10 speed up on sdb by increasing the > block size from 4k to 512k. I'm not sure what conclusion should we draw > from this observation. As a general rule, we want the block size to match that of the configured disk layout — if we care about getting the best numbers in our benchmarks. With real workloads things are always going to be slower anyway. > In particular for our most urging matter, /gnu/store/trash > removal. Moving to a faster hard drive would definitely help here, but I > still don't understand if that disk performance regression comes from > Linux, the file-system fragmentation, or the disk itself. > >> READ: bw=1547MiB/s (1622MB/s), 1547MiB/s-1547MiB/s (1622MB/s-1622MB/s), io=3055MiB (3203MB), run=1975-1975msec >> WRITE: bw=527MiB/s (553MB/s), 527MiB/s-527MiB/s (553MB/s-553MB/s), io=1042MiB (1092MB), run=1975-1975msec > > Wooh that's fast! On test could be to copy the /gnu/store/trash content > to the SAN an observe how long that it takes for this operating to > complete. Do you mean time the copy or time the removal from that storage? You know what, I’ll time both. I’ll need to get more space first. I think the trash directory is larger than the 500G that I got for testing the SAN. > Thanks for your support on that complex topic :) Hey, I’m just happy neither of us has to do this alone. Thank you! -- Ricardo