Tiered Cache-Sharing Service for Virtual Machine Images Based on Memory Pool

Zhihao Zhang, Weinan Liu, Zhenlong Song, Xinbiao Gan, Yue Yu, Yiming Zhang

Abstract: In virtualization-based cloud computing, numerous redundant tiered memory pages exist across independent virtual machines (VMs) deployed on different physical hosts within the data center. In this article, we propose fexible memory (FlexMem), a preliminary architecture designed to eliminate memory redundancy for qcow2-based VMs. First, FlexMem introduces a virtual persistent memory (PMem) device that facilitates cross-host memory consolidation by leveraging remote direct memory access (RDMA) for fast remote read operations. Second, FlexMem employs flexible backing specifications that are memory-mapped to sparse and layered qcow2 images. By delivering images to VMs through FlexMem and enabling guest direct access, user programs within the guest can directly access identical images already cached in the remote host’s memory. Our evaluation demonstrates that FlexMem significantly improves memory efficiency and the availability of VMs with reduced hardware costs, ultimately enhancing the competitiveness of cloud vendors.

External IDs:dblp:journals/micro/ZhangLSGYZ25