In Linux various special files can be found under the directory /dev. These files are called device files and behave unlike ordinary files. The most common types of device files are for block devices and character devices. These files are an interface to the actual driver (part of the Linux kernel) which in turn accesses the hardware. Another, less common, type of device file is the named pipe. The most important device files are listed in the tables below. sda First hard disk sdb Second hard disk sda1 First partition of the first hard disk sdb7 Seventh partition of the second hard disk sr0 First CD-ROM sr1 Second CD-ROM ttyS0 Serial port 0, also referred to as COM1 ttyS1 Serial port 1, also referred to as COM2 psaux PS/2 mouse device gpmdata Pseudo device, repeater data from GPM (mouse) daemon cdrom Symbolic link to the CD-ROM drive mouse Symbolic link to the mouse device file null Anything written to this device will disappear zero One can endlessly read zeros out of this device The mouse can be used in both the Linux console (with gpm) and the X window environment. Normally, this is a simple matter of installing gpm and the X server itself. Both should be configured to use /dev/input/mice as the mouse device. The correct mouse protocol is named exps2 in gpm, and ExplorerPS/2 in X. The respective configuration files are /etc/gpm.conf and /etc/X11/xorg.conf. Certain kernel modules must be loaded in order for your mouse to work. In most cases the correct modules are autodetected, but not always for old-style serial and bus mice Serial mice usually have a 9-hole D-shaped connector; bus mice have an 8-pin round connector, not to be confused with the 6-pin round connector of a PS/2 mouse or the 4-pin round connector of an ADB mouse. , which are quite rare except on very old computers. Summary of Linux kernel modules needed for different mouse types: Module Description psmouse PS/2 mice (should be autodetected) usbhid USB mice (should be autodetected) sermouse Most serial mice logibm Bus mouse connected to Logitech adapter card inport Bus mouse connected to ATI or Microsoft InPort card To load a mouse driver module, you can use the modconf command (from the package with the same name) and look in the category kernel/drivers/input/mouse. A standard installation for the amd64 architecture, including all standard packages and using the default kernel, takes up &std-system-size;MB of disk space. A minimal base installation, without the Standard system task selected, will take &base-system-size;MB. In both cases this is the actual disk space used after the installation is finished and any temporary files deleted. It also does not take into account overhead used by the file system, for example for journal files. This means that significantly more disk space is needed both during the installation and for normal system use. The following table lists sizes reported by aptitude for the tasks listed in tasksel. Note that some tasks have overlapping constituents, so the total installed size for two tasks together may be less than the total obtained by adding up the numbers. By default the installer will install the GNOME desktop environment, but alternative desktop environments can be selected either by using one of the special installation images, or by specifying the desired desktop environment during installation (see ). Note that you will need to add the sizes listed in the table to the size of the standard installation when determining the size of partitions. Most of the size listed as Installed size will end up in /usr and in /lib; the size listed as Download size is (temporarily) required in /var. Task Installed size (MB) Download size (MB) Space needed to install (MB) Desktop environment         • GNOME (default) &task-desktop-gnome-inst; &task-desktop-gnome-dl; &task-desktop-gnome-tot;   • KDE Plasma &task-desktop-kde-inst; &task-desktop-kde-dl; &task-desktop-kde-tot;   • Xfce &task-desktop-xfce-inst; &task-desktop-xfce-dl; &task-desktop-xfce-tot;   • LXDE &task-desktop-lxde-inst; &task-desktop-lxde-dl; &task-desktop-lxde-tot;   • MATE &task-desktop-mate-inst; &task-desktop-mate-dl; &task-desktop-mate-tot;   • Cinnamon &task-desktop-cinnamon-inst; &task-desktop-cinnamon-dl; &task-desktop-cinnamon-tot; Web server &task-web-inst; &task-web-dl; &task-web-tot; SSH server &task-ssh-inst; &task-ssh-dl; &task-ssh-tot; If you install in a language other than English, tasksel may automatically install a localization task, if one is available for your language. Space requirements differ per language; you should allow up to 350MB in total for download and installation.