Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!udel!gdtltr From: gdtltr@freezer.it.udel.edu (Gary Duzan) Newsgroups: comp.unix.large Subject: Re: Epoch like filesystem Message-ID: <33763@nigel.ee.udel.edu> Date: 17 Oct 90 14:18:19 GMT References: <60058@bbn.BBN.COM> <11709@celit.fps.com> Sender: usenet@ee.udel.edu Organization: Brain Dead Innovations (BDI) Lines: 40 Nntp-Posting-Host: mocha.it.udel.edu In article <11709@celit.fps.com> hutch@fps.com (Jim Hutchison) writes: =>In article <60058@bbn.BBN.COM> chowe@bbn.com (Carl Howe) writes: =>>rodney@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 -- gdtltr@freezer.it.udel.edu _o_ -------------------------- _o_ [|o o|] An isolated computer is a terribly lonely thing. [|o o|] |_O_| "Don't listen to me; I never do." -- Doctor Who |_O_|