Path: utzoo!attcan!uunet!maverick.ksu.ksu.edu!ux1.cso.uiuc.edu!uwm.edu!rpi!rodney From: rodney@sun.ipl.rpi.edu (Rodney Peck II) Newsgroups: comp.unix.large Subject: Epoch like filesystem Message-ID: Date: 13 Oct 90 00:44:26 GMT Organization: Rensselaer Polytechnic Institute, Troy NY Lines: 37 Say, I was thinking the other day about how nice it would be to have an Epoch file server here in the lab, but we already invested $150,000 in a file server with 2.5 gig on it. Instead of spending another $70,000 for the basic Epoch system, it would be really nice to use what we have. I was thinking about how annoying it was that the salesman said we couldn't use the 8mm tape drive we already have with the potential new Epoch simply because we didn't buy it from them, and it hit me... Why not write some code to make a standard sunos system behave like Epoch? Basically, this means that the hard disk is paged off to optical disk as it fills up. Then, when the pages that are on the optical disk are referenced, they are brought back on line. The directory information stays on the hard disk at all times, making things like "find" run at a reasonable speed. This could be done the right way (rewrite the kernel with proper paging schemes and that sort of thing) or the easy way. The easy way would be to do a find of the tree and make things that are really old into symbolic links to the new file system on the optical disk. Could be a shell script? So, this sort of thing would let you by an inexpensive optical jukebox (you can get the 10 platter 600 meg version for somewhere around $10k I believe), hook it up, and have a pseudo epoch filesystem. I'd like to hear what you think of this idea -- I'm planning to try it out once our jukebox arrives (we're getting the 10 platter 1 gig/platter version). I think we could put aside two platters for an experiment in this wacky idea. anxiously awaiting the intelligent unix answers.... -- Rodney