• Filesystem: Your view, using the OS. Pages in a file are logically consecutive.

  • Disk pages: Lower level view, pages on disk. Pages that are logically consecutive may or may not be adjacent.

  • On random access, read 4 consecutive pages.

  • Scan red file: 2 random accesses.

  • Scan blue file: 2 random accesses.

  • Scan green file: 3 random accesses (even though it's a smaller file).