4k sector disk drive and linux
Read this article: http://lwn.net/Articles/377895/
I just want to add my performance measures here. Drive is a WDC WD20EARS:
Misaligned partition 10GB ext2 results with bonnie++:
Version 1.03d ------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 server 5G 61962 41 59906 6 26673 1 91696 58 125708 2 170.9 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 6384 95 +++++ +++ +++++ +++ 6649 98 +++++ +++ 19556 99 server,5G,61962,41,59906,6,26673,1,91696,58,125708,2,170.9,0,16,6384,95,+++++,+++,+++++,+++,6649,98,+++++,+++,19556,99
Aligned partition with fdisk expert ("x") menu: Type "b" and move start of partition to sector 64. Attention: You loose all data in the partition!
Results with bonnie++:
Version 1.03d ------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 server 5G 107161 71 106024 12 45917 1 101213 64 125729 2 217.6 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 6316 98 +++++ +++ +++++ +++ 6680 99 +++++ +++ 19471 99 server,5G,107161,71,106024,12,45917,1,101213,64,125729,2,217.6,0,16,6316,98,+++++,+++,+++++,+++,6680,99,+++++,+++,19471,99
So you can see: the alignment has a significant impact on the performance.