path: root/en/appendix/files.xml

<!-- retain these comments for translator revision tracking -->
<!-- $Id$ -->


 <sect1 id="linuxdevices"><title>Linux Devices</title>
<para>

In Linux various special files can be found under the directory
<filename>/dev</filename>. 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 <firstterm>pipe</firstterm>.
The most important device files are listed in the tables below.

</para><para>

<informaltable><tgroup cols="2"><tbody>
<row>
  <entry><filename>fd0</filename></entry>
  <entry>First Floppy Drive</entry>
</row><row>
  <entry><filename>fd1</filename></entry>
  <entry>Second Floppy Drive</entry>
</row>
</tbody></tgroup></informaltable>

<informaltable><tgroup cols="2"><tbody>
<row>
  <entry><filename>hda</filename></entry>
  <entry>IDE Hard disk / CD-ROM on the first IDE port (Master)</entry>
</row><row>
  <entry><filename>hdb</filename></entry>
  <entry>IDE Hard disk / CD-ROM on the first IDE port (Slave)</entry>
</row><row>
  <entry><filename>hdc</filename></entry>
  <entry>IDE Hard disk / CD-ROM on the second IDE port (Master)</entry>
</row><row>
  <entry><filename>hdd</filename></entry>
  <entry>IDE Hard disk / CD-ROM on the second IDE port (Slave)</entry>
</row><row>
  <entry><filename>hda1</filename></entry>
  <entry>First partition of the first IDE hard disk</entry>
</row><row>
  <entry><filename>hdd15</filename></entry>
  <entry>Fifteenth partition of the fourth IDE hard disk</entry>
</row>
</tbody></tgroup></informaltable>

<informaltable><tgroup cols="2"><tbody>
<row>
  <entry><filename>sda</filename></entry>
  <entry>SCSI Hard disk with lowest SCSI ID (e.g. 0)</entry>
</row><row>
  <entry><filename>sdb</filename></entry>
  <entry>SCSI Hard disk with next higher SCSI ID (e.g. 1)</entry>
</row><row>
  <entry><filename>sdc</filename></entry>
  <entry>SCSI Hard disk with next higher SCSI ID (e.g. 2)</entry>
</row><row>
  <entry><filename>sda1</filename></entry>
  <entry>First partition of the first SCSI hard disk</entry>
</row><row>
  <entry><filename>sdd10</filename></entry>
  <entry>Tenth partition of the fourth SCSI hard disk</entry>
</row>
</tbody></tgroup></informaltable>

<informaltable><tgroup cols="2"><tbody>
<row>
  <entry><filename>sr0</filename></entry>
  <entry>SCSI CD-ROM with the lowest SCSI ID</entry>
</row><row>
  <entry><filename>sr1</filename></entry>
  <entry>SCSI CD-ROM with the next higher SCSI ID</entry>
</row>
</tbody></tgroup></informaltable>

<informaltable><tgroup cols="2"><tbody>
<row>
  <entry><filename>ttyS0</filename></entry>
  <entry>Serial port 0, COM1 under MS-DOS</entry>
</row><row>
  <entry><filename>ttyS1</filename></entry>
  <entry>Serial port 1, COM2 under MS-DOS</entry>
</row><row>
  <entry><filename>psaux</filename></entry>
  <entry>PS/2 mouse device</entry>
</row><row>
  <entry><filename>gpmdata</filename></entry>
  <entry>Pseudo device, repeater data from GPM (mouse) daemon</entry>
</row>
</tbody></tgroup></informaltable>

<informaltable><tgroup cols="2"><tbody>
<row>
  <entry><filename>cdrom</filename></entry>
  <entry>Symbolic link to the CD-ROM drive</entry>
</row><row>
  <entry><filename>mouse</filename></entry>
  <entry>Symbolic link to the mouse device file</entry>
</row>
</tbody></tgroup></informaltable>

<informaltable><tgroup cols="2"><tbody>
<row>
  <entry><filename>null</filename></entry>
  <entry>Anything written to this device will disappear</entry>
</row><row>
  <entry><filename>zero</filename></entry>
  <entry>One can endlessly read zeros out of this device</entry>
</row>
</tbody></tgroup></informaltable>

</para>

  <sect2>
<title>Setting Up Your Mouse</title>

<para>

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:

<informalexample><screen>
mouse =&gt; /dev/psaux  =&gt; gpm =&gt; /dev/gpmdata -&gt; /dev/mouse =&gt; X
         /dev/ttyS0             (repeater)        (symlink)
         /dev/ttyS1
</screen></informalexample>

Set the repeater protocol to be raw (in <filename>/etc/gpm.conf</filename>) while
setting X to the original mouse protocol in <filename>/etc/X11/XF86Config</filename>
or <filename>/etc/X11/XF86Config-4</filename>.

</para><para>

This approach to use gpm even in X has advantages when the mouse is
unplugged inadvertently.  Simply restarting gpm with

<informalexample><screen>
# /etc/init.d/gpm restart
</screen></informalexample>

will re-connect the mouse in software without restarting X.

</para><para>

If gpm is disabled or not installed for some reason, make sure to set X to
read directly from a mouse device such as /dev/psaux. For details, refer
to the 3-Button Mouse mini-Howto at
<filename>/usr/share/doc/HOWTO/en-txt/mini/3-Button-Mouse.gz</filename>,
<userinput>man gpm</userinput>,
<filename>/usr/share/doc/gpm/FAQ.gz</filename>, and
<ulink url="&url-xorg;current/doc/html/mouse.html">README.mouse</ulink>.

</para><para arch="powerpc">

For PowerPC, in <filename>/etc/X11/XF86Config</filename> or
<filename>/etc/X11/XF86Config-4</filename>, set the mouse device to
<userinput>"/dev/input/mice"</userinput>.

</para><para arch="powerpc">

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
<filename>/etc/sysctl.conf</filename> file.

<informalexample><screen>
# 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.
</screen></informalexample>

</para>
  </sect2>
 </sect1>

 <sect1 id="tasksel-size-list">
 <title>Disk Space Needed for Tasks</title>

<!-- Note for d-i and manual maintainers
 Sizes of tasks should be determined by running tasksel with the "new-install"
 option on a system that been fully installed without selecting any tasks. By
 selecting a task together with the "manual selection" option, aptitude will
 be started and show the sizes for the task. Use "cancel panding actions" to
 clear the slate, quit aptitude and repeat for other tasks.
 Space requirements need to be determined from tasksel as tasksel will not
 install recommended packages while selecting a task from aptitude will.

 The size for the minimal base system should be determined after running
 'aptitude clean' using 'du -hsx /'. After that the "Standard system" task
 should be installed after which the size of the standard system should be
 determined using the same method.
-->

<para>

A standard installation for the i386 architecture, including all standard
packages and using the default 2.6 kernel, takes up 442MB of disk space.
A minimal base installation, without the <quote>Standard system</quote>
task selected, will take 230MB.

</para>
<important><para>

In both cases this is the actual disk space used <emphasis>after</emphasis>
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
<emphasis>during</emphasis> the installation and for normal system use.

</para></important>
<para>

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.

</para><para>

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 <quote>Installed size</quote> will end up in
<filename>/usr</filename> and in <filename>/lib</filename>;
the size listed as <quote>Download size</quote>
is (temporarily) required in <filename>/var</filename>.

</para><para>

<informaltable><tgroup cols="4">
<thead>
<row>
  <entry>Task</entry>
  <entry>Installed size (MB)</entry>
  <entry>Download size (MB)</entry>
  <entry>Space needed to install (MB)</entry>
</row>
</thead>

<tbody>
<row>
  <entry>Desktop environment</entry>
  <entry>1267</entry>
  <entry>420</entry>
  <entry>1667</entry>
</row>

<row>
  <entry>Laptop<footnote>
  
  <para>
  There is a large overlap of the Laptop task with the Destop environment task.
  If you install both, the Laptop task will only require a few MB additional
  disk space.
  </para>

  </footnote></entry>
  <entry>50</entry>
  <entry>17</entry>
  <entry>67</entry>
</row>

<row>
  <entry>Web server</entry>
  <entry>35</entry>
  <entry>11</entry>
  <entry>46</entry>
</row>

<row>
  <entry>Print server</entry>
  <entry>277</entry>
  <entry>79</entry>
  <entry>356</entry>
</row>

<row>
  <entry>DNS server</entry>
  <entry>2</entry>
  <entry>1</entry>
  <entry>3</entry>
</row>

<row>
  <entry>File server</entry>
  <entry>49</entry>
  <entry>21</entry>
  <entry>70</entry>
</row>

<row>
  <entry>Mail server</entry>
  <entry>13</entry>
  <entry>5</entry>
  <entry>18</entry>
</row>

<row>
  <entry>SQL database</entry>
  <entry>24</entry>
  <entry>8</entry>
  <entry>32</entry>
</row>

</tbody>
</tgroup></informaltable>

<note><para>

The <emphasis>Desktop</emphasis> task will install the GNOME desktop
environment.

</para></note>

</para><para>

If you install in a language other than English, <command>tasksel</command>
may automatically install a <firstterm>localization task</firstterm>, if one
is available for your language. Space requirements differ per language;
you should allow up to 350MB in total for download and installation. 

</para>
 </sect1>