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1 nightmorph 1.1 <?xml version='1.0' encoding='UTF-8'?>
2     <!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
3 vapier 1.7 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/openrc-migration.xml,v 1.6 2008/04/15 06:17:47 nightmorph Exp $ -->
4 nightmorph 1.1
5     <guide link="/doc/en/openrc-migration.xml">
6     <title>Baselayout and OpenRC Migration Guide</title>
7    
8     <author title="Author">
9     <mail link="cardoe"/>
10     </author>
11     <author title="Author">
12     <mail link="nightmorph"/>
13     </author>
14     <author title="Contributor">
15     <mail link="uberlord"/>
16     </author>
17    
18     <abstract>
19     This guide shows you how to migrate from baselayout-1 to baselayout-2 and
20     OpenRC.
21     </abstract>
22    
23     <!-- The content of this document is licensed under the CC-BY-SA license -->
24     <!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
25     <license/>
26    
27 vapier 1.7 <version>1.4</version>
28     <date>2008-04-15</date>
29 nightmorph 1.1
30     <chapter>
31     <title>Background</title>
32     <section>
33     <title>What's baselayout?</title>
34     <body>
35    
36     <p>
37     Baselayout provides a basic set of files that are necessary for all systems to
38     function properly, such as <path>/etc/hosts</path>. It also provides the basic
39     filesystem layout used by Gentoo (i.e. <path>/etc</path>, <path>/var</path>,
40     <path>/usr</path>, <path>/home</path> directories).
41     </p>
42    
43     </body>
44     </section>
45     <section>
46     <title>What's OpenRC?</title>
47     <body>
48    
49     <p>
50     OpenRC is a dependency-based rc system that works with whatever init is provided
51     by the system, normally <path>/sbin/init</path>. However, it is <e>not</e> a
52     replacement for <path>/sbin/init</path>. The default init used by Gentoo Linux
53     is <c>sys-apps/sysvinit</c>, while Gentoo/FreeBSD uses the FreeBSD init provided
54     by <c>sys-freebsd/freebsd-sbin</c>.
55     </p>
56     </body>
57     </section>
58     <section>
59     <title>So why migrate?</title>
60     <body>
61    
62     <p>
63     Originally Gentoo's rc system was built into baselayout 1 and written entirely
64     in bash. This led to several limitations. For example, certain system calls need
65     to be accessed during boot and this required C-based callouts to be added. These
66     callouts were each statically linked, causing the rc system to bloat over time.
67     </p>
68    
69     <p>
70     Additionally, as Gentoo expanded to other platforms like
71     Gentoo/FreeBSD and Gentoo Embedded, it became impossible to require a bash-based
72     rc system. This led to a development of baselayout 2, which is written in
73     C and only requires a POSIX-compliant shell. During the development of
74     baselayout 2, it was determined that it was a better fit if baselayout merely
75     provided the base files and filesystem layout for Gentoo and the rc system
76     was broken off into its own package. Thus we have OpenRC.
77     </p>
78    
79     <p>
80     OpenRC is primarily developed by <uri link="http://roy.marples.name/openrc">Roy
81     Marples</uri> and supports all current Gentoo variations (i.e. Gentoo Linux,
82     Gentoo/FreeBSD, Gentoo Embedded, and Gentoo Vserver) and other platforms such as
83     FreeBSD and NetBSD.
84     </p>
85    
86     </body>
87     </section>
88     </chapter>
89    
90     <chapter>
91     <title>Migration to OpenRC</title>
92     <section>
93     <body>
94    
95     <p>
96 nightmorph 1.4 Migration to OpenRC is fairly straightforward; it will be pulled in as part of
97     your regular upgrade process by your package manager. The most important step
98     actually comes after you install the new <c>>=sys-apps/baselayout-2</c> and
99     <c>sys-apps/openrc</c> packages. It is <e>critical</e> that you run
100     <c>dispatch-conf</c> and ensure your <path>/etc</path> is up to date before
101     rebooting. <brite>Failure to do so will result in an unbootable system</brite>
102     and will require the use of the Gentoo LiveCD to perform the steps below to
103     repair your system.
104 nightmorph 1.1 </p>
105    
106     <p>
107     Once you've finished updating your config files, there are a few things to
108 nightmorph 1.4 verify prior to rebooting.
109     </p>
110 nightmorph 1.1
111     </body>
112     </section>
113    
114     <section id="rc_conf">
115     <title>/etc/conf.d/rc</title>
116     <body>
117    
118     <p>
119     <path>/etc/conf.d/rc</path> has been deprecated and any settings you have in
120     there will need to be migrated to the appropriate settings in
121     <path>/etc/rc.conf</path>. Please read through <path>/etc/rc.conf</path> and
122     <path>/etc/conf.d/rc</path> and migrate the settings. Once you are complete,
123     delete <path>/etc/conf.d/rc</path>.
124     </p>
125    
126     </body>
127     </section>
128     <section id="modules">
129     <title>Kernel modules</title>
130     <body>
131    
132     <p>
133     Normally, when you want certain kernel modules automatically loaded at boot, you
134     place them into <path>/etc/modules.autoload.d/kernel-2.6</path> along with any
135     parameters you wanted to pass to them. In baselayout-2, this file is not used
136     anymore. Instead, autoloaded modules and module parameters are placed in one
137     file, <path>/etc/conf.d/modules</path>, no matter the kernel version.
138     </p>
139    
140     <p>
141     An example old style configuration would be:
142     </p>
143    
144     <pre caption="/etc/modules.autoload.d/kernel-2.6">
145     ivtv
146     cx88_dvb video_br=2
147     </pre>
148    
149     <p>
150     Converting the above example would result in the following:
151     </p>
152    
153     <pre caption="/etc/conf.d/modules">
154     <comment># Modules autoloaded at boot</comment>
155     modules_2_6="ivtv cx88_dvb"
156     <comment># Module parameters</comment>
157     module_cx88_dvb_args_2_6="video_br=2"
158     </pre>
159    
160     <p>
161     In the above examples, the modules and their parameters would only be passed
162     to 2.6.x series kernels. The new configuration allows for fine grained
163     control over the modules and parameters based on kernel version.
164     </p>
165    
166     <p>
167     An in-depth example would be:
168     </p>
169    
170     <pre caption="detailed example of /etc/conf.d/modules">
171     <comment># Always load ochi1394 and ieee1394, no matter the kernel version</comment>
172     modules="ohci1394 ieee1394"
173     <comment># Only load tun and usbserial for 2.6.x series kernels</comment>
174     modules_2_6="tun usbserial"
175     <comment># Only load cx88_dvb for 2.6.23 kernels</comment>
176     modules_2_6_23="cx88_dvb"
177     <comment># Only load ivtv for 2.6.23-gentoo-r5</comment>
178     modules_2_6_23_gentoo_r5="ivtv"
179    
180     <comment># For 2.6.23-gentoo-r5, pass video_br=2 to cx88_dvb</comment>
181     module_cx88_dvb_args_2_6_23_gentoo_r5="video_br=2"
182     <comment># For 2.6.x series kernels, always pass vendor and product</comment>
183     module_usbserial_args_2_6="vendor=0x1410 product=0x2110"
184     <comment># Always pass debug to ieee1394</comment>
185     module_ieee1394_args="debug"
186     </pre>
187    
188     <note>
189     Please note the difference between <b>module_</b> and <b>modules_</b>.
190     </note>
191    
192     </body>
193     </section>
194 nightmorph 1.5 <section id="boot">
195     <title>Boot runlevel</title>
196 nightmorph 1.1 <body>
197    
198     <p>
199 nightmorph 1.5 The <c>boot</c> runlevel performs several important steps for every machine. For
200     example, making sure your root filesystem is mounted read/write, that your
201     filesystems are checked for errors, that your mountpoints are available, and
202     that the <path>/proc</path> pseudo-filesystem is started at boot.
203 nightmorph 1.1 </p>
204    
205     <p>
206 nightmorph 1.5 With OpenRC, volume management services for your block storage devices are no
207     longer run automatically at boot. This includes lvm, raid, swap, device-mapper
208     (dm), dm-crypt, evms, and the like. You must ensure the appropriate initscript
209     for these services is in the <c>boot</c> runlevel, otherwise it's possible that
210     your system will not boot!
211 nightmorph 1.1 </p>
212    
213     <p>
214     While the OpenRC ebuild will attempt to do this migration for you, you should
215 nightmorph 1.5 verify that it migrated all the volume management services properly:
216 nightmorph 1.1 </p>
217    
218 nightmorph 1.5 <pre caption="Display all services in boot runlevel">
219 nightmorph 1.1 # <i>ls -l /etc/runlevels/boot/</i>
220     </pre>
221    
222     <p>
223 nightmorph 1.5 If you don't see root, procfs, mtab, swap, and fsck in the above listing,
224     perform the following to add them to the <c>boot</c> runlevel:
225 nightmorph 1.1 </p>
226    
227     <pre caption="Adding missing volume management services to the boot runlevel">
228 nightmorph 1.5 # <i>rc-update add root boot</i>
229     # <i>rc-update add procfs boot</i>
230     # <i>rc-update add mtab boot</i>
231     # <i>rc-update add fsck boot</i>
232 nightmorph 1.1 # <i>rc-update add swap boot</i>
233     </pre>
234    
235 nightmorph 1.2 <p>
236 nightmorph 1.5 If you know you use mdraid and lvm but do not see them above, you would run
237     the following to add initscripts to the <c>boot</c> runlevel:
238 nightmorph 1.2 </p>
239    
240 nightmorph 1.6 <pre caption="Adding raid and lvm to the boot runlevel">
241 nightmorph 1.5 # <i>rc-update add raid boot</i>
242     # <i>rc-update add lvm boot</i>
243 nightmorph 1.2 </pre>
244    
245 nightmorph 1.1 </body>
246     </section>
247     <section>
248     <title>Clock</title>
249     <body>
250    
251     <p>
252     Clock settings have been renamed from <path>/etc/conf.d/clock</path> to your
253     system's native tool for adjusting the clock. This means on Linux it will be
254     <path>/etc/conf.d/hwclock</path> and on FreeBSD it will be
255 nightmorph 1.2 <path>/etc/conf.d/adjkerntz</path>. The initscript in <path>/etc/init.d/</path>
256     has also been renamed accordingly, so make sure it's in the appropriate
257     runlevel.
258 nightmorph 1.1 </p>
259    
260     <p>
261     Additionally, the <c>TIMEZONE</c> variable is no longer in this file. Its
262     contents are instead found in the <path>/etc/timezone</path> file. Please review
263     both of these files to ensure their correctness.
264     </p>
265    
266     </body>
267     </section>
268     <section>
269     <title>XSESSION</title>
270     <body>
271    
272     <p>
273     The XSESSION variable is no longer found in <path>/etc/rc.conf</path>. The
274     <c>x11-apps/xinit</c> package now provides <path>/etc/env.d/90xsession</path>,
275     which can be used to set the XSESSION variable.
276     </p>
277    
278     <p>
279     This variable will <b>NOT</b> be migrated for you by default, so you will need
280     to edit <path>/etc/env.d/90xsession</path>.
281     </p>
282    
283     <impo>
284     You must run <c>env-update</c> after creating a file in <path>/etc/env.d</path>,
285     and then logout and login for it to take effect.
286     </impo>
287    
288     </body>
289     </section>
290     <section>
291 vapier 1.7 <title>EDITOR / PAGER</title>
292 nightmorph 1.1 <body>
293    
294     <p>
295 vapier 1.7 The EDITOR variable is no longer found in <path>/etc/rc.conf</path>. Both
296     EDITOR and PAGER are set by default in /etc/profile. You should change this as
297     needed in your <path>~/.bashrc</path> (or equivalent) file or create
298     <path>/etc/env.d/99editor</path> and set the system default there.
299 nightmorph 1.1 </p>
300    
301     <impo>
302     You must run <c>env-update</c> after creating a file in <path>/etc/env.d</path>,
303     and then logout and login for it to take effect. If you set the variable in
304     <path>~/.bashrc</path>, you can re-source the file with <c>source
305     ~/.bashrc</c>.
306     </impo>
307    
308     </body>
309     </section>
310     <section>
311     <title>Finishing up</title>
312     <body>
313    
314     <p>
315     Once you've finished updating your config files and initscripts, the last thing
316     to do is <b>reboot</b>. This is necessary because system state information is
317     not preserved during the upgrade, so you'll need to provide it with a fresh
318     boot.
319     </p>
320    
321     </body>
322     </section>
323     </chapter>
324     </guide>

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