Linux disk performance test statement

1. Read performance test command:

dd iflag=direct if=/home/zhouyan/1.dat of=/dev/null bs=2M count=500


2. Write performance test command:

dd oflag=direct if=/dev/zero of=/home/zhouyan/2.dat bs=2M count=500


3. Read and write performance test command:

dd iflag=direct oflag=direct if=/home/zhouyan/1.dat of=/home/zhouyan/2. dat bs=2M count=500