Data storage performance enhancement through a write activity level metric recorded in high performance block storage metadata

A sequence of fixed-size blocks defines a page (e.g., in a server system, storage subsystem, DASD, etc.). Each fixed-size block includes a data block and a footer. A high performance block storage metadata unit associated with the page is created from a confluence of the footers. The confluence of footers has space available for application metadata. In an embodiment, the metadata space is utilized to record a "write activity level" metric, and a timestamp. The metric indicates the write frequency or "hotness" of the page, and its value changes over time as the activity level changes. Frequently accessed pages may be mapped to higher performance physical disks and infrequently accessed pages may be mapped to lower power physical disks.