chapter08 - • Introduction • File Service Architecture...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: • Introduction • File Service Architecture • Sun Network File System • The Andrew File System • Recent advances • Summary Chapter 7: Distributed File Systems • File system – persistent storage • Distributed file system – persistent storage – information sharing – similar (in some case better) performance and reliability • Various kinds of storage systems Introduction • Responsibilities – Organization, storage, retrieval, naming, sharing and protection • Important concepts related to file – File • Include data and attributes – Directory • A special file that provides a mapping from text names to internal file identifiers – Metadata • Extra management information; including attribute, directory etc • File system architecture • File system operations – Applications access via library procedures Characteristics of file systems • Transparency – access transparency – location transparency – mobility transparency – performance transparency – scaling transparency • Concurrent file updates – concurrency control • File replication – better performance & fault tolerance • Hardware and operating system heterogeneity Distributed file system requirements • Fault tolerance – idempotent operations: support at-least-semantics – stateless server: restart from crash without recovery • Consistency – One-copy update semantics • Security – Authenticate, access control, secure channel • Efficiency – comparable with, or better than local file systems in performance and reliability Distributed file system requirements … continuted • SUN NFS – First file service that was designed as a product [1984] – Adopted as a internet standard – Supported by almost platforms, e.g. Windows NT, Unix • Andrew File System – Campus information sharing system in CMU [1986] – 800 workstations and 40 servers at CMU [1991] Case studies • Introduction • File Service Architecture • Sun Network File System • The Andrew File System • Recent advances • Summary Chapter 7: Distributed File Systems • File service architecture • Flat file service – Operate on the contents of files – Unique file identifier (UFID) • Directory service – Provide a mapping between text names to UFIDs • Client module – Support applications accessing remote file service transparently – E.g. iterative request to directory service, cache files Three components of a file service • Flat file service operations • Comparison with Unix – No open and close – Read or write specifying a starting point • Fault tolerance reasons for the differences – Repeatable operations • except for create, all operations are idempotent – Stateless servers • E.g. without pointer when operate on files • restart after crash without recovery Flat file service interface • Unix File System – User’s access rights are checked against the access mode requested in the open call • Stateless DFS – DFS’s interface is opened to public...
View Full Document

{[ snackBarMessage ]}

Page1 / 58

chapter08 - • Introduction • File Service Architecture...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online