The hard disk has been declared dead so many times over the last ten years, but let’s face it: The hard drive is alive and kicking. It’s still far more cost effective than flash and has a significant advantage when it comes to durability for long term storage.
Most persistent volumes, especially those with a lot of files and data, follow a pattern where only a subset of the files are accessed frequently. The bulk of the data, often 80%, are cold but need to be accessible quickly at any time. Storing all cold data on flash is often prohibitively expensive, or at least a waste of resources. Unless your users select specific storage classes for certain applications (see our tutorial how to create those with Quobyte), you have to provide general purpose persistent volumes that balance price and performance.
Quobyte offers multiple methods to help you achieve this goal without torturing your users with slow tiering to secondary storage systems.
As you can see, it’s quite easy to get the best of flash and HDD on your Quobyte cluster, even when you don’t know what kind of IO patterns to expect from your user’s stateful applications.