forked from lix-project/lix
* Started on the introduction.
This commit is contained in:
Eelco Dolstra
parent
74867e72f2
commit
4b7b0bd12c
|
|
@ -12,11 +12,128 @@
|
||||||
<chapter>
|
<chapter>
|
||||||
<title>Introduction</title>
|
<title>Introduction</title>
|
||||||
|
|
||||||
<para>
|
<sect1>
|
||||||
Nix is a system for the automatic creation and distribution of data, such
|
<title>The problem space</title>
|
||||||
as computer programs and other software artifacts.
|
|
||||||
</para>
|
|
||||||
|
|
||||||
|
<para>
|
||||||
|
Nix is a system for controlling the automatic creation and distribution
|
||||||
|
of data, such as computer programs and other software artifacts. This
|
||||||
|
is a very general problem, and there are many applications that fall
|
||||||
|
under this description.
|
||||||
|
</para>
|
||||||
|
|
||||||
|
<sect2>
|
||||||
|
<title>Build management</title>
|
||||||
|
|
||||||
|
<para>
|
||||||
|
Build management tools are used to perform <emphasis>software
|
||||||
|
builds</emphasis>, that is, the construction of derived products
|
||||||
|
such as executable programs from source code. A commonly used build
|
||||||
|
tool is Make, which is a standard tool on Unix systems. These tools
|
||||||
|
have to deal with several issues:
|
||||||
|
<itemizedlist>
|
||||||
|
<listitem>
|
||||||
|
<para>
|
||||||
|
</para>
|
||||||
|
</listitem>
|
||||||
|
</itemizedlist>
|
||||||
|
</para>
|
||||||
|
|
||||||
|
</sect2>
|
||||||
|
|
||||||
|
<sect2>
|
||||||
|
<title>Package management</title>
|
||||||
|
|
||||||
|
<para>
|
||||||
|
After software has been built, is must also be
|
||||||
|
<emphasis>deployed</emphasis> in the intended target environment,
|
||||||
|
e.g., the user's workstation. Examples include the Red Hat package
|
||||||
|
manager (RPM), Microsoft's MSI, and so on. Here also we have to deal
|
||||||
|
with several issues:
|
||||||
|
<itemizedlist>
|
||||||
|
<listitem>
|
||||||
|
<para>
|
||||||
|
The <emphasis>creation</emphasis> of packages from some formal
|
||||||
|
description of what artifacts should be distributed in the
|
||||||
|
package.
|
||||||
|
</para>
|
||||||
|
</listitem>
|
||||||
|
<listitem>
|
||||||
|
<para>
|
||||||
|
The <emphasis>deployment</emphasis> of packages, that is, the
|
||||||
|
mechanism by which we get them onto the intended target
|
||||||
|
environment. This can be as simple as copying a file, but
|
||||||
|
complexity comes from the wide range of possible installation
|
||||||
|
media (such as a network install), and the scalability of the
|
||||||
|
process (if a program must be installed on a thousand systems,
|
||||||
|
we do not want to visit each system and perform some manual
|
||||||
|
steps to install the program on that system; that is, the
|
||||||
|
complexity for the system administrator should be constant, not
|
||||||
|
linear).
|
||||||
|
</para>
|
||||||
|
</listitem>
|
||||||
|
</itemizedlist>
|
||||||
|
</para>
|
||||||
|
</sect2>
|
||||||
|
|
||||||
|
</sect1>
|
||||||
|
|
||||||
|
<sect1>
|
||||||
|
<title>The Nix system</title>
|
||||||
|
|
||||||
|
<para>
|
||||||
|
...
|
||||||
|
</para>
|
||||||
|
|
||||||
|
<para>
|
||||||
|
Existing tools in this field generally both a underlying model (such as
|
||||||
|
the derivation graph of build tools, or the versioning scheme that
|
||||||
|
determines when two packages are <quote>compatible</quote> in a package
|
||||||
|
management system) and a formalism that allows ...
|
||||||
|
</para>
|
||||||
|
|
||||||
|
<para>
|
||||||
|
Following the principle of separation of mechanism and policy, the Nix
|
||||||
|
system separates the <emphasis>low-level aspect</emphasis> of file
|
||||||
|
system object management form the <emphasis>high-level
|
||||||
|
aspect</emphasis> of the ...
|
||||||
|
</para>
|
||||||
|
|
||||||
|
</sect1>
|
||||||
|
|
||||||
|
</chapter>
|
||||||
|
|
||||||
|
|
||||||
|
<!--======================================================================-->
|
||||||
|
|
||||||
|
<chapter>
|
||||||
|
<title>A Guided Tour</title>
|
||||||
|
|
||||||
|
<para>
|
||||||
|
Bla bla
|
||||||
|
</para>
|
||||||
|
</chapter>
|
||||||
|
|
||||||
|
|
||||||
|
<!--======================================================================-->
|
||||||
|
|
||||||
|
<chapter>
|
||||||
|
<title>Fix Language Reference</title>
|
||||||
|
|
||||||
|
<para>
|
||||||
|
Bla bla
|
||||||
|
</para>
|
||||||
|
</chapter>
|
||||||
|
|
||||||
|
|
||||||
|
<!--======================================================================-->
|
||||||
|
|
||||||
|
<chapter>
|
||||||
|
<title>Nix Syntax and Semantics</title>
|
||||||
|
|
||||||
|
<para>
|
||||||
|
Bla bla
|
||||||
|
</para>
|
||||||
</chapter>
|
</chapter>
|
||||||
|
|
||||||
|
|
||||||
|
|
@ -99,4 +216,74 @@ $ make install</screen>
|
||||||
</chapter>
|
</chapter>
|
||||||
|
|
||||||
|
|
||||||
|
<!--======================================================================-->
|
||||||
|
|
||||||
|
<appendix>
|
||||||
|
<title>Troubleshooting</title>
|
||||||
|
|
||||||
|
<sect1>
|
||||||
|
<title>Database hangs</title>
|
||||||
|
|
||||||
|
<para>
|
||||||
|
If Nix or Fix appear to hang immediately after they are started, Nix's
|
||||||
|
database is probably <quote>wedged</quote>, i.e., some process died
|
||||||
|
while it held a lock on the database. The solution is to ensure that
|
||||||
|
no other processes are accessing the database and then run the
|
||||||
|
following command:
|
||||||
|
</para>
|
||||||
|
|
||||||
|
<screen>
|
||||||
|
$ db_recover -e -h <replaceable>prefix</replaceable>/var/nix/db</screen>
|
||||||
|
|
||||||
|
<para>
|
||||||
|
Here, <replaceable>prefix</replaceable> should be replaced by Nix's
|
||||||
|
installation prefix.
|
||||||
|
</para>
|
||||||
|
|
||||||
|
</sect1>
|
||||||
|
|
||||||
|
|
||||||
|
<sect1>
|
||||||
|
<title>Database logfile removal</title>
|
||||||
|
|
||||||
|
<para>
|
||||||
|
Every time a Nix database transaction takes place, Nix writes a record
|
||||||
|
of this transaction to a <emphasis>log</emphasis> in its database
|
||||||
|
directory to ensure that the operation can be replayed in case of a
|
||||||
|
application or system crash. However, without manual intervention,
|
||||||
|
the log grows indefinitely. Hence, unused log files should be deleted
|
||||||
|
periodically. This can be accomplished using the following command:
|
||||||
|
</para>
|
||||||
|
|
||||||
|
<screen>
|
||||||
|
$ rm `db_archive -a -h <replaceable>prefix</replaceable>/var/nix/db`</screen>
|
||||||
|
|
||||||
|
</sect1>
|
||||||
|
|
||||||
|
|
||||||
|
</appendix>
|
||||||
|
|
||||||
|
|
||||||
|
<!--======================================================================-->
|
||||||
|
|
||||||
|
<appendix>
|
||||||
|
<title>Known problems</title>
|
||||||
|
|
||||||
|
<itemizedlist>
|
||||||
|
|
||||||
|
<listitem>
|
||||||
|
<para>
|
||||||
|
Nix should automatically recover the Berkeley DB database.
|
||||||
|
</para>
|
||||||
|
</listitem>
|
||||||
|
|
||||||
|
<listitem>
|
||||||
|
<para>
|
||||||
|
Nix should automatically remove Berkeley DB logfiles.
|
||||||
|
</para>
|
||||||
|
</listitem>
|
||||||
|
|
||||||
|
</itemizedlist>
|
||||||
|
</appendix>
|
||||||
|
|
||||||
</book>
|
</book>
|
||||||
|
|
|
||||||
Loading…
Reference in a new issue