-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 1/23/2014 7:24 AM, Stan Hoeppner wrote: > Increasing stripe_cache_size above the default as I suggested will > ALWAYS increase write speed, often by a factor of 2-3x or more on > modern hardware. It should speed up destructive resyncs > considerably, as well as normal write IO. Once your array has > settled down after the inits and resyncs and what not, run some > parallel FIO write tests with the default of 256 and then with > 2048. You can try 4096 as well, but with 5 rusty drives 4096 will > probably cause a slight tailing off of throughput. 2048 should be > your sweet spot. You can also just time a few large parallel file > copies. You'll be amazed at the gains. I have never seen it make a difference on destructive syncs on 3 or 4 disk raid5 arrays and when you think about it, that makes perfect sense. The point of the cache is to coalesce small random writes into full stripes so you don't have to do a RMW cycle, so for streaming IO, it isn't going to do a thing. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (MingW32) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJS6rOcAAoJEI5FoCIzSKrwz0YIAJMJG6C0aePvKfXJlQy1mmbp AaFHQX8MgIgj3kgiNj8s83uWEdVZfzaQpcc3oJcB0PD2FTHxt+204e8C2wZz0b5N 4zZim1YRec67LTRkLwNeko5HrkiapmWf0FYmx95d3gNvb0UGUbh98hRItgSX78NS Lu+afQWOLCqiv3UjMHpG4Blb37oT0cp2pttuGKbDZTS4OSgd/qWRvcQ5sRQ09338 n40EiCWaIIlWlSQJ0r6GUylTOiys+JziB+qcHK6SvK+9gF3VdYN955GXNKxMn7t1 A3rFbeVsC0MSRcMytVmMk3cFQDn+xhZ1ZvHvkbLagj9i0uLcC+1cR6KIeScdQC4= =iFoR -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
