IOPS

http://www.cnblogs.com/sink_cup/archive/2012/09/14/ssd_iops_sql_nosql.html

http://www.techrepublic.com/blog/the-enterprise-cloud/calculate-iops-in-a-storage-array/

https://www.zhihu.com/question/28111947/answer/39551626

http://f.dataguru.cn/thread-385925-1-1.html