Bài giảng Hệ điều hành nâng cao - Chapter 17: Distributed - File Systems giúp người đọc nắm được các kiến thức cơ bản về hệ thống file, cách đặt tên file, truy cập file từ xa, nhân bản tệp,.Hy vọng đây là tài liệu tham khảo hữu ích cho bạn. | Chapter 17: Distributed-File Systems 1 Chapter 17 Distributed-File Systems Background Naming and Transparency Remote File Access Stateful versus Stateless Service File Replication An Example: AFS 2 Chapter Objectives To explain the naming mechanism that provides location transparency and independence To describe the various methods for accessing distributed files To contrast stateful and stateless distributed file servers To show how replication of files on different machines in a distributed file system is a useful redundancy for improving availability To introduce the Andrew file system (AFS) as an example of a distributed file system 3 Background Distributed file system (DFS) – a distributed implementation of the classical time-sharing model of a file system, where multiple users share files and storage resources A DFS manages set of dispersed storage devices Overall storage space managed by a DFS is composed of different, remotely located, smaller storage spaces There is usually a correspondence between constituent storage spaces and sets of files 4 DFS Structure Service – software entity running on one or more machines and providing a particular type of function to a priori unknown clients Server – service software running on a single machine Client – process that can invoke a service using a set of operations that forms its client interface A client interface for a file service is formed by a set of primitive file operations (create, delete, read, write) Client interface of a DFS should be transparent, ., not distinguish between local and remote files 5 Naming and Transparency Naming – mapping between logical and physical objects Multilevel mapping – abstraction of a file that hides the details of how and where on the disk the file is actually stored A transparent DFS hides the location where in the network the file is stored For a file being replicated in several sites, the mapping returns a set of the locations of this file’s replicas; both the | Chapter 17: Distributed-File Systems 1 Chapter 17 Distributed-File Systems Background Naming and Transparency Remote File Access Stateful versus Stateless Service File Replication An Example: AFS 2 Chapter Objectives To explain the naming mechanism that provides location transparency and independence To describe the various methods for accessing distributed files To contrast stateful and stateless distributed file servers To show how replication of files on different machines in a distributed file system is a useful redundancy for improving availability To introduce the Andrew file system (AFS) as an example of a distributed file system 3 Background Distributed file system (DFS) – a distributed implementation of the classical time-sharing model of a file system, where multiple users share files and storage resources A DFS manages set of dispersed storage devices Overall storage space managed by a DFS is composed of different, remotely located, smaller storage spaces There is .
