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Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!simtel!zombie.ncsc.mil!news.mathworks.com!europa.chnt.gtegsc.com!howland.reston.ans.net!Germany.EU.net!zib-berlin.de!news.tu-chemnitz.de!irz401!uriah.heep!not-for-mail From: j@uriah.heep.sax.de (J Wunsch) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: Unprivileged mounts (was Re: Suggestion for 2.1) Date: 24 Jun 1995 11:59:24 +0200 Organization: Private FreeBSD site, Dresden. Lines: 63 Message-ID: <3sgnls$6hf@uriah.heep.sax.de> References: <3r7888$280@germany.eu.net> <3saqif$lrc@news.bu.edu> <3sc8l9$2ar@bonnie.tcd-dresden.de> <3sfj2q$q62@news.bu.edu> NNTP-Posting-Host: uriah.heep.sax.de Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Mikhail Teterin <mi@cs.bu.edu> wrote: >|DOS does no ``mounting on demand'', it does no mounting at all. > >|What are you thinking of? Please elaborate on it... >... So, in FreeBSD, >that may look like: "I insert a floppy and say 'cd /diska'". I realize, >that this will be absolutely out of Unix traditions, and will make trouble >with Unix partitioned floppies, but there is definelty something to be done. Hmm, looks like some ``auto-mounter''. It has been done for NFS access, i have no idea how much work it would be for something like floppy access. One problem is still remaining: when should that thingie try to unmount the floppy again? As soon as there's no more active vnode on the floppy? Will cause you the overhead of mounting it over and over again if you're just cd'ing back and forth. Only just when ejecting the floppy? Well, you need an additional command (this is also the Silicon Graphics way), so go on to the next paragraph. I've rather thought about a simple help in order to get the disk mounted. For example, i'm using a small (Perl) script in order to mount a CD, so i can say just ``do-mount cd'' instead of ``su - r <entering password> mount -o ro -t cd9660 /dev/cd0a /cd''. When i'm done, i say ``do-mount -u cd''. Perhaps it could also be placed in some menu system, sort of an andmin's help system. Seen so on some sysv's. >Having a proper entries in /etc/fstab will do it, but not now, as DOS does not >require you to know a format of the floppy. And FreeBSD may, actually, free >you from knowing what kind of FS that is. It will take longer to mount (trying >all the combinations, starting with the most frequently used, of course), but >those who know exactly the format, may still do it in todays way. I'm thinking about automagic format detection for the floppy driver. Pray to whomever you like that my personal time resources will allow me executing my plans. Btw., DOS does not do automagic format detection. It can only read its very own disks, only for a format with 512 bytes per sector (and it does it by analyzing the data in the first sector). It cannot handle raw disks via the operating system interface (only via the BIOS interface), i.e. you cannot read a tar floppy easily (e.g. by ``tar xvf A:'', where tar doesn't know about the special meaning of just `A:' instead of `A:/foo/bar.tar'). Many BIOSes fail to read formats they do not know of, even if DOS could handle them (e.g. 720 KB on a 5.25in DS/DD floppy). You would have a hard time to read a ufs floppy in DOS. :) Well, i've seen the Silicon Graphics approach of automatically trying to determine the type of the floppy -- and i do not like it. (Even though they've got the better hardware and are able to detect the insertion of the floppy -- which we cannot do.) There are too many weird floppy formats, low-level as well as high-level. This is not to say that such a tool to simplify the process is a Good Thing (TM). -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ Never trust an operating system you don't have sources for. ;-)