I have run off another IO benchmark on EC2 using IOZone.
The OS is Centos 4.4 OS, running on Amazon Machine Image (AMI), which is a Zen based Virtual Machine (VM).
There seem to be a couple of sweet spots identified by the benchmark.
- To stay in CPU Cache keep your file size smaller than under 256KB and read and write in 64 Byte chunks
- If you must read from larger files, the size of the cache is the maximum size to remain in memory
- Reading is best done between 64 Byte to 512 Byte chunks.
- At least on EC2 stay away from reading 16 Kbyte files in 128 byte, 1K and 8K chunks.
http://s3.amazonaws.com/dbadojo_benchmark/iozone_ec2_write.GIF
http://s3.amazonaws.com/dbadojo_benchmark/iozone_ec2_read.GIF
http://s3.amazonaws.com/dbadojo_benchmark/iozone_ec2_random_read.GIF
http://s3.amazonaws.com/dbadojo_benchmark/iozone_ec2_random_write.GIF
http://s3.amazonaws.com/dbadojo_benchmark/iozone_benchmark_ec2.zip (Right Click SAVE AS)
Have Fun
Paul