Linux Devices
In Linux you have various special files in
/dev. These files are called device files. In
the Unix world accessing hardware is different. There you have a
special file which actually runs a driver which in turn accesses the
hardware. The device file is an interface to the actual system
component. Files under /dev also behave
differently than ordinary files. Below are the most important device
files listed.
fd0
First Floppy Drive
fd1
Second Floppy Drive
hda
IDE Hard disk / CD-ROM on the first IDE port (Master)
hdb
IDE Hard disk / CD-ROM on the first IDE port (Slave)
hdc
IDE Hard disk / CD-ROM on the second IDE port (Master)
hdd
IDE Hard disk / CD-ROM on the second IDE port (Slave)
hda1
First partition of the first IDE hard disk
hdd15
Fifteenth partition of the fourth IDE hard disk
sda
SCSI Hard disk with lowest SCSI ID (e.g. 0)
sdb
SCSI Hard disk with next higher SCSI ID (e.g. 1)
sdc
SCSI Hard disk with next higher SCSI ID (e.g. 2)
sda1
First partition of the first SCSI hard disk
sdd10
Tenth partition of the fourth SCSI hard disk
sr0
SCSI CD-ROM with the lowest SCSI ID
sr1
SCSI CD-ROM with the next higher SCSI ID
ttyS0
Serial port 0, COM1 under MS-DOS
ttyS1
Serial port 1, COM2 under MS-DOS
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
Everything pointed to this device will disappear
zero
One can endlessly read zeros out of this device
Setting Up Your Mouse
The mouse can be used in both the Linux console (with gpm) and the X window
environment. The two uses can be made compatible if the gpm repeater is used
to allow the signal to flow to the X server as shown:
mouse => /dev/psaux => gpm => /dev/gpmdata -> /dev/mouse => X
/dev/ttyS0 (repeater) (symlink)
/dev/ttyS1
Set the repeater protocol to be raw (in /etc/gpm.conf) while
setting X to the original mouse protocol in /etc/X11/XF86Config
or /etc/X11/XF86Config-4.
This approach to use gpm even in X has advantages when the mouse is
unplugged inadvertently. Simply restarting gpm with
# /etc/init.d/gpm restart
will re-connect the mouse in software without restarting X.
If gpm is disabled or not installed with some reason, make sure to set X to
read directly from the mouse device such as /dev/psaux. For details, refer
to the 3-Button Mouse mini-Howto at
/usr/share/doc/HOWTO/en-txt/mini/3-Button-Mouse.gz,
man gpm,
/usr/share/doc/gpm/FAQ.gz, and
README.mouse.
For PowerPC, in /etc/X11/XF86Config or
/etc/X11/XF86Config-4, set the mouse device to
"/dev/input/mice".
Modern kernels give you the capability to emulate a three-button mouse
when your mouse only has one button. Just add the following lines to
/etc/sysctl.conf file.
# 3-button mouse emulation
# turn on emulation
/dev/mac_hid/mouse_button_emulation = 1
# Send middle mouse button signal with the F11 key
/dev/mac_hid/mouse_button2_keycode = 87
# Send right mouse button signal with the F12 key
/dev/mac_hid/mouse_button3_keycode = 88
# For different keys, use showkey to tell you what the code is.
Disk Space Needed for Tasks
The base installation for i386 using the default 2.4 kernel,
including all standard packages, requires 573MB of disk space.
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.
Note that you will need to add the sizes listed in the table to the size
of the base installation when determining the size of partitions.
Most of the size listed as Installed size
will end up in
/usr; the size listed as Download size
is (temporarily) required in /var.
Task
Installed size (MB)
Download size (MB)
Space needed to install (MB)
Desktop
1392
460
1852
Web server
36
12
48
Print server
168
58
226
DNS server
2
1
3
File server
47
24
71
Mail server
10
3
13
SQL database
66
21
87
The Desktop task will install both the Gnome and KDE
desktop environments.
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 200MB in total for download and installation.