IT has used auto-tiering for years as a way to move data from expensive fast storage to cheaper and slower secondary bulk storage. The approach was at best a crude approximation, being only able to distinguish between objects on the basis of age or lack of use. This meant, for instance, that documents and files stayed much longer in expensive storage than was warranted. There simply was no mechanism for sending such files automatically to cheap storage.
Now, to make life even more complicated, we’ve added a new tier of storage at each end of the food chain. At the fast end, we now have ultra-fast NVDIMM offering an even more expensive and, more importantly space limited, way to boost access speed, while at the other end of the spectrum the cloud is reducing the need for in-house long-term storage even more. Simple auto-tiering doesn’t do enough to optimize the spectrum of storage in a 4-state system like this. We need to get much savvier about where we keep things.
The successor to auto-tiering has to take into account traffic patterns for objects and plan their lifecycle accordingly. For example, a Word document may be stored as a fully editable file in today’s solutions, but the reality is that most of these documents, once fully edited, become read-only objects moved in their entirety to be read. If changes occur, a new, renamed, version of the document is created and the old one kept intact.