Epoch like filesystem

[Gary Duzan]

In article <11709 at celit.fps.com> hutch at fps.com (Jim Hutchison) writes:
=>In article <60058 at bbn.BBN.COM> chowe at bbn.com (Carl Howe) writes:
=>>rodney at sun.ipl.rpi.edu (Rodney Peck II) writes:
=>>>[...deleted...]
=>>>Why not write some code to make a standard sunos system behave like Epoch?
=>>>[...deleted...]
=>
=>>Plan 9 from Bell Labs does a similar sort of thing.  They back up the
=>>entire contents of their hard disk to optical every night as part of
=>>the standard file system tree.  [ ... ]
=>
=>O.k. I'll bite, how does such a system last?  At the end of each month does
=>it make a "level 0 dump" file system?   Certainly at some point the on-line
=>optical disk resources will be exhausted and some sort of consolidation will
=>be needed, or the system will have to grow continuously at a rate determined
=>by day-to-day disk activity.  It seems that consolidation could limit this
=>growth, and allow for old "level 0 dump" disks to be migrated onto a shelf
=>or into a safe place.
=>
=>With the current speeds for optical drives, I'd kind of guess this system
=>is not useful as a primary storage device.  Presuming WORM and not M-O,
=>it couldn't be used for frequent migration, due to the rapid rate at which
=>the platters would fill up with minor revisions.
=>--

   I'm no expert, but I did read some on it. Plan 9 uses a WORM Jukebox,
which can hold quite a bit of data. The Hard Disk can be viewed as a
cache for the Jukebox. That way you get speed, size, and reliability.

                                        Gary Duzan
                                        Time  Lord
                                    Third Regeneration



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