mrush@cscihp.ecst.csuchico.edu (Matt "C P." Rush) (03/07/91)
After such a great response to my last question, here's another! Is there any way to Mount an OD (as root, probably) and then set som thing so that no one can eject it? The system runs off of a Hard Drive, and has 1 Optical Drive that I'd like to permanently Mount for additional, seldom- used files. Since the Cube is readily accessible, I'd like to have some way of preventing users from coming in, unmounting the OD, and walking off with or damaging 256MB of files and a $100 cartridge. Is this possible? -- C P. mrush@cscihp.ecst.csuchico.edu
bennett@mp.cs.niu.edu (Scott Bennett) (03/08/91)
In article <1991Mar07.091952.28376@ecst.csuchico.edu> mrush@cscihp.ecst.csuchico.edu (Matt "C P." Rush) writes: > > After such a great response to my last question, here's another! > > Is there any way to Mount an OD (as root, probably) and then set som >thing so that no one can eject it? The system runs off of a Hard Drive, and >has 1 Optical Drive that I'd like to permanently Mount for additional, seldom- >used files. > Since the Cube is readily accessible, I'd like to have some way of >preventing users from coming in, unmounting the OD, and walking off with or >damaging 256MB of files and a $100 cartridge. Is this possible? (At that price you must have bought it before last November. Unlike the automobiles sold before last November, it is most likely now worth *more* than when it was new. :-( ) I don't *think* so. Here's why: if you mount /dev/od0a /someodname as root, nobody can umount(8) it, *but* that still leaves /dev/od1a available for other people to mount an OD onto and when they do that, out pops the original OD. :-( You can't easily get around it by also doing a mount /dev/od1a /anotherodname as root and then taking the first one with you because anytime the system needs to look at /someodname (e.g. a user does a df(1)), the system ejects the od1a disk in order to load the od0a disk in order to look at /someodname. Likewise, if *you* looked at /someodname so that you could get the od1a disk back, the system would still eject the od0a disk in order to look at the od1a disk anytime it needed to look at /anotherodname. Now, another tack might be to reply 'n' to the load message when the system is switching disks. This message appears on the screen in case you *cannot* load the requested disk for some reason, in which case you're supposed to reply 'n'. The hitch is that, if you reply 'n', the device goes offline. 8-| When a device bearing a mounted file system goes offline, you (or the system) might decide there were much *worse* problems to deal with than what you started with. Sorry. BTW, if NeXT's MACH happens to have some way to bring a device back online once it has been knocked offline, *please* let me know. When a device is bumped off in 4.3BSD, you're stuck, plain and simple. A reboot is required to get it back. > > -- C P. > mrush@cscihp.ecst.csuchico.edu Scott Bennett, Comm. ASMELG, CFIAG Systems Programming Northern Illinois University DeKalb, Illinois 60115 ********************************************************************** * Internet: bennett@cs.niu.edu * * BITNET: A01SJB1@NIU * *--------------------------------------------------------------------* * "The good news is that Saddam Hussein will be tried for war * * crimes. The bad news is that the case will be heard by the * * Senate Ethics Committee."--quoted in _The_Wall_Street_Journal_ * **********************************************************************
regn@informatik.uni-ulm.de (Robert Regn) (04/12/91)
In <1991Mar07.091952.28376@ecst.csuchico.edu> mrush@cscihp.ecst.csuchico.edu (Matt "C P." Rush) writes: > Is there any way to Mount an OD (as root, probably) and then set som >thing so that no one can eject it? The system runs off of a Hard Drive, and >has 1 Optical Drive that I'd like to permanently Mount for additional, seldom- >used files. > Since the Cube is readily accessible, I'd like to have some way of >preventing users from coming in, unmounting the OD, and walking off with or >damaging 256MB of files and a $100 cartridge. Is this possible? Yes: create a process which has the 'current directory' somewhere on the od
bennett@mp.cs.niu.edu (Scott Bennett) (04/12/91)
In article <regn.671390337@julia> regn@informatik.uni-ulm.de (Robert Regn) writes: >In <1991Mar07.091952.28376@ecst.csuchico.edu> mrush@cscihp.ecst.csuchico.edu (Matt "C P." Rush) writes: > > >> Is there any way to Mount an OD (as root, probably) and then set som >>thing so that no one can eject it? The system runs off of a Hard Drive, and >>has 1 Optical Drive that I'd like to permanently Mount for additional, seldom- >>used files. >> Since the Cube is readily accessible, I'd like to have some way of >>preventing users from coming in, unmounting the OD, and walking off with or >>damaging 256MB of files and a $100 cartridge. Is this possible? > >Yes: create a process which has the 'current directory' somewhere on the od No, no, this does *not* work. You appear to be responding to a very old thread. Read the rest before you continue posting on any thread. Scott Bennett, Comm. ASMELG, CFIAG Systems Programming Northern Illinois University DeKalb, Illinois 60115 ********************************************************************** * Internet: bennett@cs.niu.edu * * BITNET: A01SJB1@NIU * *--------------------------------------------------------------------* * "Well, I don't know, but I've been told, in the heat of the sun * * a man died of cold..." Oakland, 19 Feb. 1991, first time since * * 25 Sept. 1970!!! Yippee!!!! Wondering what's NeXT... :-) * **********************************************************************