Abstract: Metadata is essential for the successful operation of data files, as it acts as the underlying data that helps maintain and manage the namespace, permissions, and address of the file data blocks. The performance of metadata services has a direct impact on the overall performance of the file system, as these operations can account for a significant portion, up to 80%, of file system activity. Large-scale distributed file systems (DFS) have emerged to meet the rising demand for data storing. These systems provide users with access to numerous storage units spread across various locations. The widespread use of large-scale DFSs as the foundation for a range of computing systems and applications, particularly in the era of Big Data, highlights the importance of efficient metadata management. This paper seeks to offer an enhanced knowledge of the current status of metadata systems in large-scale DFSs, this paper presents a comprehensive overview of the latest research in the field. DFSs are defined by three aspects: scalability, performance, and availability. Moreover, the study evaluates various challenges and limitations in the current research, providing valuable insight for future studies. Overall, the study attempts to give a complete knowledge of the present scenario of metadata services across large-scale DFSs and to recommend areas for future research and development.