Chico CSCI 640 - Chapter 17: Distributed­File Systems Part 2 (21 pages)

Previewing pages 1, 2, 20, 21 of 21 page document View the full content.
View Full Document

Chapter 17: Distributed­File Systems Part 2



Previewing pages 1, 2, 20, 21 of actual document.

View the full content.
View Full Document
View Full Document

Chapter 17: Distributed­File Systems Part 2

59 views

Lecture Notes


Pages:
21
School:
California State University, Chico
Course:
Csci 640 - Operating Systems

Unformatted text preview:

Chapter 17 Distributed File Systems Part 2 Chapter 17 Distributed File Systems Chapter 17 1 Background Naming and Transparency Remote File Access Chapter 17 2 Stateful versus Stateless Service File Replication An Example AFS Operating System Concepts 17 2 Silberschatz Galvin and Gagne 2005 Chapter Objectives 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 Operating System Concepts 17 3 Silberschatz Galvin and Gagne 2005 Stateful File Service Stateful File Service Server either tracks each file being accessed by a each client or else it is stateless Stateful File Service Client opens a file Server fetches information about the file from its disk stores it in its memory and gives the client a connection identifier unique to the client and the open file Identifier is used for subsequent accesses until session ends A stateful service is characterized by a connection between the client and the server during a session Server keeps main memory information about all of its clients Server reclaims main memory space used by clients when no longer active Operating System Concepts 17 4 Silberschatz Galvin and Gagne 2005 Stateful File Service 2 Advantages We certainly get Increased performance Fewer disk accesses because file information is cached in main memory in the server and can be readily accessed by the connection identifier In Unix the server fetches an inode and provides the client a file descriptor which serves as an index to an in core table of inodes Stateful server knows if a file was opened for sequential access and can thus read ahead the next blocks Operating System Concepts 17 5 Silberschatz Galvin and Gagne 2005 Stateless File Server Stateless This mechanism only provides blocks of data as when requested with no knowledge of how the client uses or modifies the data Here each request is self contained by itself Thus no



View Full Document

Access the best Study Guides, Lecture Notes and Practice Exams

Loading Unlocking...
Login

Join to view Chapter 17: Distributed­File Systems Part 2 and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Chapter 17: Distributed­File Systems Part 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?