Storage cluster for persistency, CXL pools for caching

The emergence of Compute Express Link (CXL) enables new opportunities for scaling memory across data center nodes, introducing a high-speed, coherent memory pool that multiple systems can access simultaneously.While CXL offers a promising alternative to traditional memory and storage hierarchies, its practical integration with the operating systems's page cache remains an open question.In this paper, we investigate the feasibility of leveraging CXL for storage data caching, specifically by extending the operating system's page cache to span CXL memory pools.We prototype a design using virtiofs and a CXL memory expander in a virtualized Linux environment, demonstrating its impact on shared file caching across multiple virtual machines.Our evaluation shows that while CXL enables efficient internode data sharing, its bandwidth limitations require careful consideration in cache placement strategies.We discuss the trade-offs between local memory, CXL-backed caches, and storage access patterns, offering insights into the potential of CXL to enhance data-intensive workloads in modern data centers.