Software Defined Networking (SDN) has always looked a bit like a solution in search of a problem, at least in the enterprise data center. But there are lots of potential applications that need a dynamic and scalable network. In my mind, storage is chief among these, since scalability and flexibility has always been extremely difficult to achieve.
Veritas Volume Manager
Mac OS X was majorly deficient in that it lacked a volume manager. This wouldn’t seem like a big deal to the average user, but held back the operating system in so many ways. A volume manager brings storage virtualization to an operating system, allowing storage capacity efficiently to be managed and manipulated. But all this has changed in Mac OS X 10.7 â€œLionâ€ with CoreStorage.
Thin provisioning needs communication to function, and zero page reclaim is only the array side of the story. WRITE_SAME helps reduce I/O load, but the server needs to use it. Wouldn’t it be nice if the operating system, file system, or volume manager would use these commands to help recover capacity?