What’s In The Box? Are Storage Vendors Undersizing Cache?
If you’ve heard the term Megacaches and auto-tiering you may have a leg up already. However, for most folks, caching and auto-tiering is generally seen as a bit of a black-box that lives inside a storage vendor offering. There can be some information on the architecture exposed, but in some cases we get told
Understanding Why Caching is Good, Yet May Be Undersized
As we know, tiered storage systems those with multiple types of storage that place data in different tiers based on algorithms such as frequency of use, There are many factors that drive what data can be stored in each tier.
While caching for many enterprise storage environments is generally sized quite large to host as much data in the “hot” tier as possible. Many auto-tiering environments are designed with significantly less space in the cache which may affect a number of different metrics including performance, and possibly even more wear-and-tear on the magnetic disks than you think you will endure.
Dimitris Krekoukias has put together a great post that talks about this here which is a nice primer to understanding the inner workings of caching and auto-tiering.