Computer Science 330
Operating Systems

Spring 2012, Siena College

Home     Syllabus     Schedule

Agenda

• Announcements
• File Systems
• Directories - listings of files
  • directory concept
  • directory operations
  • directory organization
    • single-level
    • two-level
    • tree-structured
    • acyclic-graph: links/shortcuts/aliases
    • general graph: upward-pointing links create cycles
  • directory implementation
    • linear list
    • hash tables
• Disks and partitions
  • a system may have multiple disks, each of which contains multiple partitions
  • we create a file system (more later) in each partition
  • mounting: drive letters in Windows, paths in Unix
  • In Unix, a virtual file system layer translates generic paths to the correct partitions (local of varying types, network-accessible)
  • partitioning: why and how?
• File System Implementations
  • want to provide: convenience, protection, efficiency
  • issues:
    • allocation of disk blocks to files/directories
    • track available blocks
    • do this efficiently

Lecture Assignment 19

Due at the start of class, Tuesday, April 10.

Please submit answers to these questions either as a hard copy (typeset or handwritten are OK) or by email to jteresco AT siena.edu by the start of class. Please use a clear subject line when submitting by email (e.g., CS 330 Lecture Assignment 19, Joe Student). We will discuss these questions at the start of class, so no late submissions are accepted.

The readings for next class are SG&G Chapter 10.

• SG&G Exercise 9.13, p. 420 (2 points)
• SG&G Exercise 9.17, p. 421 (2 points)

Examples

• morelinks