Here are some bonnie numbers for a few tests: 2.6.20, only 1 drive active in md device (other drive pulled for testing): Version 1.03 ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP testbox 7G 45165 76 55461 8 25677 5 53573 90 66251 7 194.1 0 ------Sequential Create------ --------Random Create-------- -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++ testbox,7G,45165,76,55461,8,25677,5,53573,90,66251,7,194.1,0,16,+++++,+++,+++++, +++,+++++,+++,+++++,+++,+++++,+++,+++++,+++ 2.6.20, 2 drives in raid1: Version 1.03 ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP testbox 7G 47633 80 56795 10 27598 5 53675 89 66643 7 283.6 0 ------Sequential Create------ --------Random Create-------- -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++ testbox,7G,47633,80,56795,10,27598,5,53675,89,66643,7,283.6,0,16,+++++,+++,+++++ ,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++ 2.6.21-rc2 (for completeness), 2 drives in raid1: Version 1.03 ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP testbox 7G 48128 83 56330 10 28183 5 53173 89 66425 6 307.1 0 ------Sequential Create------ --------Random Create-------- -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++ testbox,7G,48128,83,56330,10,28183,5,53173,89,66425,6,307.1,0,16,+++++,+++,+++++ ,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++ Just about the only stat in these tests that show a marked improvement between one and two drives is Random Seeks (which makes sense). What doesn't make sense is that none of the Sequential Input numbers increase. Shouldn't I be seeing close to a 100% improvement? Of course a 100% increase in performance is the theoretical maximum, but these numbers show no improvement at all. Both drives are 320Gb Seagate 7200RPM Barracudas, part number ST3320620AS. The motherboard is a SuperMicro PDSME+. Any insight will be appreciated. Dan - 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