Aidis.102 net.periphs utcsrgv!utzoo!decvax!duke!mcnc!idis!dan Tue Mar 23 22:20:37 1982 Using SMS floppy disks on a VAX Our installation is getting a Scientific Micro Systems floppy disk system (FWT1127S) for our VAX. It is RX02 compatible and has an extended mode that provides on-line formatting and supports double sided diskettes and several IBM formats (i.e. larger sector sizes) that increase storage capacity by 23% (up to 2464 blocks per diskette). There are supposed to be six other vmunix sites that have ordered similar equipment. Does anyone have experience using these drives on a VAX 11/780 unibus? Has anyone developed a driver that uses more than the RX02 compatible features? We intend to place the floppy drive in a terminal room so that our users will have convenient off line storage and we can assign student disk quotas ruthlessly. Has anyone considered the implications of installing such a device on a unix system? There must be a mechanism for allocating drives. If we wish to allow user file structures (and we do), there must be a privileged program for mounting diskettes and the driver must prohibit special file I/O on a mounted diskette. There may still be ways for a user to sneak a setuid file past the mounting utility. Therefore we will probably modify the kernel to ignore setuid bits from the floppy block devices. Cached blocks from dismounted diskettes may be a problem. Must the length of the diver's active buffer queue be limited to avoid filling up the system cache with write behind blocks? Have I forgotten anything? Dan Strick ...!duke!mcnc!idis!dan ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.