The exponential growth of digital information is imposing increasing scale and efficiency demands on modern storage infrastructures. As infrastructure complexity increases, so does the difficulty in ensuring quality of service, maintainability, and resource fairness, raising unprecedented performance, scalability, and programmability challenges. Software-Defined Storage (SDS) addresses these challenges by cleanly disentangling control and data flows, easing management, and improving control functionality of conventional storage systems. Despite its momentum in the research community, many aspects of the paradigm are still unclear, undefined, and unexplored, leading to misunderstandings that hamper the research and development of novel SDS technologies. In this article, we present an in-depth study of SDS systems, providing a thorough description and categorization of each plane of functionality. Further, we propose a taxonomy and classification of existing SDS solutions according to different criteria. Finally, we provide key insights about the paradigm and discuss potential future research directions for the field.

中文翻译：

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软件定义存储系统的调查和分类

数字信息的指数级增长对现代存储基础设施提出了越来越高的规模和效率要求。随着基础设施复杂性的增加，确保服务质量、可维护性和资源公平性的难度也在增加，从而引发前所未有的性能、可扩展性和可编程性挑战。软件定义存储 (SDS) 通过清晰地分离控制和数据流、简化管理和改进传统存储系统的控制功能来应对这些挑战。尽管它在研究界势头强劲，但该范式的许多方面仍不清楚、未定义和未探索，导致误解，阻碍了新型 SDS 技术的研究和开发。在本文中，我们对 SDS 系统进行了深入研究，提供每个功能平面的全面描述和分类。此外，我们根据不同的标准提出了现有 SDS 解决方案的分类和分类。最后，我们提供了关于范式的关键见解，并讨论了该领域潜在的未来研究方向。