This morning we received a request to create an EC2 instance in AWS for an Oracle database. The application that was intending to benchmark on this EC2 instance tended to be very I/O intensive. In the past we had been using general-purpose disks rather than provisioned IOPS. To ensure that this application got the best I/O performance, they wanted the disks to be provisioned at the highest possible IOPS rate. Amazon has a restriction that the IOPS:GB ratio cannot exceed 30:1. We were striping the disks to improve I/O such that each ASM group consisted of 4 disks. We did some math and came up with the below structure:
IOPS #of disks Size per disk Ratio
(GB)
Arch 3000 4 100 30
ASM1 6000 4 200 30
ASM2 6000 4 200 30
Total size = 2000 gb
