Lecture 6
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Files and filesystems

inode
 - key data structure in UNIX-like filesystems

Files have two parts
 - file inode (metadata)
 - file data

Directories associate file names with inodes
  (specifically, inode numbers)

file metadata in an inode
 - owner
 - group
 - size
 - permissions
 - pointers to data blocks (in some format)
 ...



Where are filesystems stored?
 - persistent arrays
   - array entries are "blocks"
   - 4K traditionally, but can be bigger or smaller

To access, kernel gives device a block number, gets back block contents