Mikael, > -----Original Message----- > From: Mikael Carneholm [mailto:Mikael.Carneholm@xxxxxxxxxxxxxxx] > Sent: Friday, July 28, 2006 2:05 AM > > My bonnie++ results are found in this message: > http://archives.postgresql.org/pgsql-performance/2006-07/msg00164.php > Apologies if I've already said this, but those bonnie++ results are very disappointing. The sequential transfer rates between 20MB/s and 57MB/s are slower than a single SATA disk, and your SCSI disks might even do 80MB/s sequential transfer rate each. Random access is also very poor, though perhaps equal to 5 disk drives at 500/second. By comparison, we routinely get 950MB/s sequential transfer rate using 16 SATA disks and 3Ware 9550SX SATA RAID adapters on Linux. On Solaris ZFS on an X4500, we recently got this bonnie++ result on 36 SATA disk drives in RAID10 (single thread first): 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 thumperdw-i-1 32G 120453 99 467814 98 290391 58 109371 99 993344 94 1801 4 ------Sequential Create------ --------Random Create-------- -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 +++++ +++ +++++ +++ +++++ +++ 30850 99 +++++ +++ +++++ +++ Bumping up the number of concurrent processes to 2, we get about 1.5x speed reads of RAID10 with a concurrent workload (you have to add the rates together): 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 thumperdw-i-1 32G 111441 95 212536 54 171798 51 106184 98 719472 88 1233 2 ------Sequential Create------ --------Random Create-------- -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 26085 90 +++++ +++ 5700 98 21448 97 +++++ +++ 4381 97 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 thumperdw-i-1 32G 116355 99 212509 54 171647 50 106112 98 715030 87 1274 3 ------Sequential Create------ --------Random Create-------- -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 26082 99 +++++ +++ 5588 98 21399 88 +++++ +++ 4272 97 So that's 2500 seeks per second, 1440MB/s sequential block read, 212MB/s per character sequential read. - Luke
