1. 读性能测试命令:
dd iflag=direct if=/home/zhouyan/1.dat of=/dev/null bs=2M count=500
2. 写性能测试命令:
dd oflag=direct if=/dev/zero of=/home/zhouyan/2.dat bs=2M count=500
3. 读写性能测试命令:
dd iflag=direct oflag=direct if=/home/zhouyan/1.dat of=/home/zhouyan/2.dat bs=2M count=500