Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!clyde.concordia.ca!thunder.mcrcim.mcgill.edu!snorkelwacker.mit.edu!mit-eddie!media-lab!lacsap From: lacsap@media-lab.MEDIA.MIT.EDU (Pascal Chesnais) Newsgroups: comp.sys.next Subject: Re: How do you backup 105 MB Disk ? Summary: Just the FACTS! Message-ID: <4732@media-lab.MEDIA.MIT.EDU> Date: 5 Jan 91 17:27:04 GMT References: <7788@umd5.umd.edu> Organization: MIT Media Lab, Cambridge, MA Lines: 59 In this period of everyone trying to be helpful while using new hardware and a new OS, I would like to remind people to show some restraint and try out their panaceas before posting. Scott's message was essentially correct, but I would like to concisely review the umounting and ejecting of floppy and optical disks. The following information assumes that you were manipulating Floppy or Optical disks as a normal user, meaning that when you put in the disk it appeared on the top shelf of the workspace viewer. Floppy disks that appear on the workspace dock can usually be unmounted by dragging the floppy or optical disk icon off the top shelf of the dock into the recycler icon. This will not work if the disk is in use by some other application, which happens if you are connected to a directory from the Terminal or some other application. Once you have cleared these applications the floppy or optical disk should umount *and* eject cleanly. You can also unmount the disk from a unix shell using /etc/umount command. Again this will fail if some application is busy. /etc/umount will *not* eject the disk. The umount command tells the operating system to no longer recognize the filesystem on the disk. The operating system will automatically mount an inserted optical or floppy disk in the root directory with the label name. So if I put in an initialized floppy or optical diskette with the name "Untitiled" I would see it mounted as /Untitled using the df command. To eject the floppy or disk optical disk once operating system no longer has it mounted (use df to verify this true) you can use the /etc/disk command. You need to have superuser shell to do this. /etc/disk -e /dev/rfd0a will eject the floppy disk, and /etc/disk -e /dev/rod0a will eject the optical disk. It is important to understand that umount and mount deal with the operating system integrating the filesystem, and the disk command deals with low level disk manipulations. Using the disk command or any other mechanism to eject a disk before the operating system has cleanly unmounted can result in data being damaged on the disk. The eject function of the disk command can also be performed at the monitor level. Using a safety pin on the floppy drive or the NextTool on the optical drive should always be considered to be a last ditch measure for extracting the media from the drive. I really wish that NeXT would post similar stuff in a timely fashion in addition to having this information in NextAnswers. I hope this information is useful, and that people will correct its contents if it is false or mis-stated. Is someone still collecting information for the commonly asked questions? pasc -- Pascal Chesnais, Research Specialist, Electronic Publishing Group Media Laboratory, E15-348, 20 Ames Street, Cambridge, Ma, 02139 (617) 253-0311 email: lacsap@plethora.media.mit.edu (NeXT)