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Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!nexus.coast.net!news.sprintlink.net!news.clark.net!rwatson From: rwatson@clark.net (Robert Watson) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: Suggestion for 2.1 Date: 22 Jun 1995 12:58:10 GMT Organization: The Star-Lit BBS, Bethesda, Maryland, USA Lines: 37 Message-ID: <3sbpd2$1s3@clarknet.clark.net> References: <3r7888$280@germany.eu.net> <3s0ils$7i9@multivac.orthanc.com> <3s3o6h$5k0@bonnie.tcd-dresden.de> <3s7h66$j4l@iii1.iii.net> <3s8qj7$meh@bonnie.tcd-dresden.de> <3saqif$lrc@news.bu.edu> NNTP-Posting-Host: clark.net Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Newsreader: TIN [version 1.2 PL2] Mikhail Teterin (mi@cs.bu.edu) wrote: : Some time ago (21 Jun 1995 12:00:07 +0200) honorable J Wunsch, : residing at j@bonnie.heep.sax.de wrote: : |It's not a CPU time hog, Peter, but a memory hog. Waking up every 5 : |or 10 seconds prevents a daemon from being swapped. Have a few of : I'm sorry, if I am obviously wrong, but how about some kind of "mounting : on demand"? Similar to how DOS does it... The process we were discussin, that woke up every x seconds, was originally one to check for mount change requirements. DOS doesn't bother with mounting -- it just reads when yu access the drive letter -- and since all mount points under does (X:\) are enforced through the operating system (You can't put it anywhere else without a TSR that modifies the file interface, and that would be messy as you'd never know which programs are going to use your routines, and which won't.. I think append does this, but I personally would try to avoid append) -- since Unix doesn't know where you would put the mount,and because file access occurs pretty requently all over the place, it wouldn't neccesarily be a good idea to check a device every time a directory was accessed. It also wouldn't be consistent with the UFS file system -- having stuff randomly disappear without an unmount is bad. Actually, I guess that's the key problem with mounting on directory access--when should the systemm unmount, and what happens if the disk radnomly disappears or is replaced? Acually -- it is possible to tell if the disk has been removed/change d-- I believe Microsoft (Symantec?) used it in MS BAckup -- the drive light stays on and backup can tell when you've put the new disk in. Of course, they run a compatibility test firstt that apparently fails on some machines.. And having the drive light always on is disconcerting in terms of the purpose of a drive light -- telling when yuo shoudn't remove the disk ;). That's one features I've always liked about macs (and non-caddy CD-ROMs) -- the ability to detect a disk insert/eject. -- Robert Watson rwatson@sidwell.edu http://www.sidwell.edu/~rwatson/ The goal of science is to build better mousetraps. The goal of nature is to build better mice.