In this talk we present FlexAlloc: a lean block allocator focused on bridging the gap between raw block device access in user space and data management through monolithic file systems.

Flexible Data Placement (FDP) represents the latest development in mainstream data placement technology for NVMe. Although its use-cases resemble those of other NVMe features, such as Streams and ZNS, the differences have significant implications for the implementation within host storage stacks and applications. As host stacks adopt various data placement technologies, the risk of bloated codebases and redundant implementations rises, increasing maintenance costs for large mainline projects.