Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!rpi!rodney From: rodney@sun.ipl.rpi.edu (Rodney Peck II) Newsgroups: comp.unix.large Subject: Re: Epoch like filesystem Message-ID: Date: 17 Oct 90 16:20:17 GMT References: Organization: Rensselaer Polytechnic Institute, Troy NY Lines: 47 In article I said: > >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? > >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). Well, after extensive and tiring flipping through the trade magazines and calling dealers, I found out some more information. 10 disk 600meg erasable disks are very popular and are standardized. The 1gig isn't and is only made by maxstor. It could be completely non-interchangable inside of a year. also, the 10 disk jukebox normally comes with no software to let it work reasonably with the filesystem. For example, consider what happens when you have say, 6 platter sides mounted and a sync command comes along. Remember that there is only one disk drive, 10 disks, each with two sides, and it takes an average 6 seconds to mount a side. could be a big performance problem there since update sends out sync commands all the time. So, most of the vendors don't have support software, just the jukeboxes. A company that I would like your comments on, sells a package that has a jukebox, and some caching software that handles all the filesystem stuff. It takes up 30 or so meg on your machine to work as the cache and directory space for the jukebox. It keeps track of all the files in the library including disks that aren't in the machine at that time. So, you could have any amount of data appear to be present on the filesystem. Requests for files on disks in someone's desk cause mount requests to the operator to be made. The software allows for security type things to prevent users from reading files that aren't theirs and all of that. The system doesn't move older files off the main filesystem like epoch does, however. Basically, this seems like a decent package -- does anyone have any horror stories to share about this company (R squared)? The whole thing comes to $17,000 including 10 disks (a $2000 value) and the software and they fly out to install it. -- Rodney