I am mounting an image, and just realized that I have to create thedirectory for mounting point first. The command mount won't mountto a non-existing directory.But I seem to remember in some cases, when I insert some externaldevice, such as external HDD and CD, I don't have to create mountingpoint myself. So I wonder when mounting points are required to becreated by myself and when not?Is it correct that mounting point directories can be createdanywhere? Then what is the purposes of the directories /mnt and /media? Aren't they for hosting mounting points of devices?PS: I am under Ubuntu 12.04.Thanks!
Creating mounting point
ubuntu;mount
You can indeed create a mount point directory anywhere. /mnt and /media are conventions, not technical requirements, just like e.g., /home. /media is used in particular for auto-mounting. Some part of your desktop environment (possibly udisks) auto-mounts removable media when its connected. It does so by creating a directory under /media, and running mount (just like you would by hand). An image isn't connected (unlike a USB thumb drive, for example), so the desktop environment isn't noticing it and auto-mounting it./mnt is often used for remote file servers. Unlike /media, your desktop environment won't automatically mount stuff there.  If you're not using /mnt for remote file servers, its a perfectly good place for your temporary mount.You can see descriptions of the conventions for these directories in the Filesystem Hierarchy Standard.