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The "FS2_Design" page has been changed by brane:
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Comment:
Describe versioned filesystem concepts.

  = The Versioned Filesystem =
  
+ Subversion's versioned filesystem is a set of snapshots of the state of a 
tree of nodes. Changes to the tree are described by ''transactions'', which are 
a set of mutations of the tree state. Discrete states of the tree are called 
''revisions'' and are represented by immutable transactions. Each snapshot 
(except for the first, which has none and is called ''revision 0'') has exactly 
one predecessor and at most one immutable successor. Any number of mutable 
transactions can exist at the same time. The set of revisions is a temporally 
ordered sequence; the last or ''youngest'' revision is called the ''HEAD''. New 
revisions are created by ''merging'' the changes described by a mutable 
transaction with the tree state represented by HEAD and appending the resulting 
revision to the sequence, creating a new HEAD.
+ 
+ [[attachment:vfs-snapshot-sequence.svg]]
+ 
+ Nodes are either ''files'', which are containers of unstructured data, or 
''directories'', which are lists of named files and directories. The root node 
of this tree is always a directory. At any point in time during the 
filesystem's lifetime, each node (except the root) will have exactly one parent.
+ 

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