What's a Filesystem?

• The disk hardware presents a generic interface

• Each block of data has a number (or three)

• Asking for data block 19686144 is no fun

• One of the jobs of the OS is to provide files

• Named collections of data

• When you ask for file /usr/local/apache/logs/access_log, how does it know which data blocks hold the data?

• The filesystem (FS) provides this index

• Also permissions, directory structure, etc.

• Filesystem operations include:

        open     read      write
        link     unlink    rename
        symlink  readlink  chmod
        chown    stat      truncate

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Copyright © 2001 M. J. Dominus