Virtualize and share non-volatile memories in user space

Abstract

Emerging non-volatile memory (NVM) has attractive characteristics such as DRAM-like low-latency together with the non-volatility of storage devices. Recently, byte-addressable, memory bus-attached NVM has become available. This paper addresses the problem of combining a smaller, faster byte-addressable NVM with a larger, slower storage device, such as SSD, to create the impression of a larger and faster byte-addressable NVM which can be shared across multiple applications concurrently. In this paper, we propose vNVML, a user space library for virtualizing and sharing NVM. vNVML provides for applications transaction-like memory semantics that ensures write ordering, durability, and persistency guarantees across system failures. vNVML exploits DRAM for read caching to improve performance and potentially to reduce the number of writes to NVM, extending the NVM lifetime. vNVML is implemented in C and evaluated with realistic workloads to show that vNVML allows applications to share NVM efficiently, both in a single OS and when docker-like containers are employed. The results from the evaluation show that vNVML incurs less than 10% overhead while providing the benefits of an expanded virtualized NVM space to the applications, and allowing applications to safely share the virtual NVM.