diff options
Diffstat (limited to 'doc/apt_preferences.5.xml')
| -rw-r--r-- | doc/apt_preferences.5.xml | 60 |
1 files changed, 41 insertions, 19 deletions
diff --git a/doc/apt_preferences.5.xml b/doc/apt_preferences.5.xml index 9a4791c08..abcf56744 100644 --- a/doc/apt_preferences.5.xml +++ b/doc/apt_preferences.5.xml @@ -14,7 +14,7 @@ &apt-email; &apt-product; <!-- The last update date --> - <date>04 May 2009</date> + <date>16 February 2010</date> </refentryinfo> <refmeta> @@ -53,6 +53,17 @@ earliest in the &sources-list; file. The APT preferences file does not affect the choice of instance, only the choice of version.</para> +<para>Preferences are a strong power in the hands of a system administrator +but they can become also their biggest nightmare if used without care! +APT will not questioning the preferences so wrong settings will therefore +lead to uninstallable packages or wrong decisions while upgrading packages. +Even more problems will arise if multiply distribution releases are mixed +without a good understanding of the following paragraphs. +Packages included in a specific release aren't tested in and +therefore doesn't always work as expected in older or newer releases or +together with other packages from different releases. +You have been warned.</para> + <para>Note that the files in the <filename>/etc/apt/preferences.d</filename> directory are parsed in alphanumeric ascending order and need to obey the following naming convention: The files have no or "<literal>pref</literal>" @@ -87,6 +98,12 @@ algorithm to set the priorities of the versions of a package. Assign: <variablelist> <varlistentry> +<term>priority 1</term> +<listitem><simpara>to the versions coming from archives which in their <filename>Release</filename> +files are marked as "NotAutomatic: yes" like the debian experimental archive.</simpara></listitem> +</varlistentry> + +<varlistentry> <term>priority 100</term> <listitem><simpara>to the version that is already installed (if any).</simpara></listitem> </varlistentry> @@ -105,7 +122,9 @@ algorithm to set the priorities of the versions of a package. Assign: <para>If the target release has not been specified then APT simply assigns priority 100 to all installed package versions and priority 500 to all -uninstalled package versions.</para> +uninstalled package versions, expect versions coming from archives which +in their <filename>Release</filename> files are marked as "NotAutomatic: yes" - +these versions get the priority 1.</para> <para>APT then applies the following rules, listed in order of precedence, to determine which version of a package to install. @@ -184,8 +203,15 @@ Pin: origin "" Pin-Priority: 999 </programlisting> -<simpara>A note of caution: the keyword used here is "<literal>origin</literal>". -This should not be confused with the Origin of a distribution as +<simpara>A note of caution: the keyword used here is "<literal>origin</literal>" +which can be used to match a hostname. The following record will assign a high priority +to all versions available from the server identified by the hostname "ftp.de.debian.org"</simpara> +<programlisting> +Package: * +Pin: origin "ftp.de.debian.org" +Pin-Priority: 999 +</programlisting> +<simpara>This should <emphasis>not</emphasis> be confused with the Origin of a distribution as specified in a <filename>Release</filename> file. What follows the "Origin:" tag in a <filename>Release</filename> file is not an Internet address but an author or vendor name, such as "Debian" or "Ximian".</simpara> @@ -200,11 +226,11 @@ Pin-Priority: 50 </programlisting> <simpara>The following record assigns a high priority to all package versions -belonging to any distribution whose Codename is "<literal>squeeze</literal>".</simpara> +belonging to any distribution whose Codename is "<literal>&testing-codename;</literal>".</simpara> <programlisting> Package: * -Pin: release n=squeeze +Pin: release n=&testing-codename; Pin-Priority: 900 </programlisting> @@ -337,7 +363,7 @@ APT priorities: <para>The <filename>Release</filename> file is normally found in the directory <filename>.../dists/<replaceable>dist-name</replaceable></filename>: for example, <filename>.../dists/stable/Release</filename>, -or <filename>.../dists/woody/Release</filename>. +or <filename>.../dists/&stable-codename;/Release</filename>. It consists of a single multi-line record which applies to <emphasis>all</emphasis> of the packages in the directory tree below its parent. Unlike the <filename>Packages</filename> file, nearly all of the lines in a <filename>Release</filename> @@ -365,14 +391,14 @@ Pin: release a=stable <term>the <literal>Codename:</literal> line</term> <listitem><simpara>names the codename to which all the packages in the directory tree belong. For example, the line -"Codename: squeeze" +"Codename: &testing-codename;" specifies that all of the packages in the directory tree below the parent of the <filename>Release</filename> file belong to a version named -<literal>squeeze</literal>. Specifying this value in the APT preferences file +<literal>&testing-codename;</literal>. Specifying this value in the APT preferences file would require the line: </simpara> <programlisting> -Pin: release n=squeeze +Pin: release n=&testing-codename; </programlisting> </listitem> </varlistentry> @@ -458,10 +484,6 @@ distribution.</para> <para>Each record in the APT preferences file can optionally begin with one or more lines beginning with the word <literal>Explanation:</literal>. This provides a place for comments.</para> - -<para>The <literal>Pin-Priority:</literal> line in each APT preferences record is -optional. If omitted, APT assigns a priority of 1 less than the last value -specified on a line beginning with <literal>Pin-Priority: release ...</literal>.</para> </refsect2> </refsect1> @@ -576,14 +598,14 @@ the example configurations above. <programlisting> Explanation: Uninstall or do not install any Debian-originated package versions -Explanation: other than those in the distribution codenamed with squeeze or sid +Explanation: other than those in the distribution codenamed with &testing-codename; or sid Package: * -Pin: release n=squeeze +Pin: release n=&testing-codename; Pin-Priority: 900 Explanation: Debian unstable is always codenamed with sid Package: * -Pin: release a=sid +Pin: release n=sid Pin-Priority: 800 Package: * @@ -594,7 +616,7 @@ Pin-Priority: -10 <para>With a suitable &sources-list; file and the above preferences file, any of the following commands will cause APT to upgrade to the -latest version(s) in the release codenamed with <literal>squeeze</literal>. +latest version(s) in the release codenamed with <literal>&testing-codename;</literal>. <programlisting> apt-get install <replaceable>package-name</replaceable> @@ -606,7 +628,7 @@ apt-get dist-upgrade <para>The following command will cause APT to upgrade the specified package to the latest version from the <literal>sid</literal> distribution. Thereafter, <command>apt-get upgrade</command> will upgrade -the package to the most recent <literal>squeeze</literal> version if that is +the package to the most recent <literal>&testing-codename;</literal> version if that is more recent than the installed version, otherwise, to the most recent <literal>sid</literal> version if that is more recent than the installed version. |