/[gentoo]/xml/htdocs/doc/en/openrc-migration.xml
Gentoo

Contents of /xml/htdocs/doc/en/openrc-migration.xml

Parent Directory Parent Directory | Revision Log Revision Log


Revision 1.17 - (show annotations) (download) (as text)
Mon Nov 30 07:39:15 2009 UTC (7 years, 3 months ago) by nightmorph
Branch: MAIN
Changes since 1.16: +9 -8 lines
File MIME type: application/xml
update various paths and runlevel names for bug 292261

1 <?xml version='1.0' encoding='UTF-8'?>
2 <!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
3 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/openrc-migration.xml,v 1.16 2009/11/12 17:43:39 nightmorph Exp $ -->
4
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 <version>1.11</version>
28 <date>2009-11-29</date>
29
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
57 </body>
58 </section>
59 <section>
60 <title>So why migrate?</title>
61 <body>
62
63 <p>
64 Originally Gentoo's rc system was built into baselayout 1 and written entirely
65 in bash. This led to several limitations. For example, certain system calls need
66 to be accessed during boot and this required C-based callouts to be added. These
67 callouts were each statically linked, causing the rc system to bloat over time.
68 </p>
69
70 <p>
71 Additionally, as Gentoo expanded to other platforms like
72 Gentoo/FreeBSD and Gentoo Embedded, it became impossible to require a bash-based
73 rc system. This led to a development of baselayout 2, which is written in
74 C and only requires a POSIX-compliant shell. During the development of
75 baselayout 2, it was determined that it was a better fit if baselayout merely
76 provided the base files and filesystem layout for Gentoo and the rc system
77 was broken off into its own package. Thus we have OpenRC.
78 </p>
79
80 <p>
81 OpenRC is primarily developed by <uri link="http://roy.marples.name/openrc">Roy
82 Marples</uri> and supports all current Gentoo variations (i.e. Gentoo Linux,
83 Gentoo/FreeBSD, Gentoo Embedded, and Gentoo Vserver) and other platforms such as
84 FreeBSD and NetBSD.
85 </p>
86
87 </body>
88 </section>
89 </chapter>
90
91 <chapter>
92 <title>Migration to OpenRC</title>
93 <section>
94 <body>
95
96 <p>
97 Migration to OpenRC is fairly straightforward; it will be pulled in as part of
98 your regular upgrade process by your package manager. The most important step
99 actually comes after you install the new <c>>=sys-apps/baselayout-2</c> and
100 <c>sys-apps/openrc</c> packages. It is <e>critical</e> that you run
101 <c>dispatch-conf</c> and ensure your <path>/etc</path> is up to date before
102 rebooting. <brite>Failure to do so will result in an unbootable system</brite>
103 and will require the use of the Gentoo LiveCD to perform the steps below to
104 repair your system.
105 </p>
106
107 <p>
108 Once you've finished updating your config files, there are a few things to
109 verify prior to rebooting.
110 </p>
111
112 </body>
113 </section>
114
115 <section id="rc_conf">
116 <title>/etc/conf.d/rc</title>
117 <body>
118
119 <p>
120 <path>/etc/conf.d/rc</path> has been deprecated and any settings you have in
121 there will need to be migrated to the appropriate settings in
122 <path>/etc/rc.conf</path>. Please read through <path>/etc/rc.conf</path> and
123 <path>/etc/conf.d/rc</path> and migrate the settings. Once you are complete,
124 delete <path>/etc/conf.d/rc</path>.
125 </p>
126
127 </body>
128 </section>
129 <section id="modules">
130 <title>Kernel modules</title>
131 <body>
132
133 <p>
134 Normally, when you want certain kernel modules automatically loaded at boot, you
135 place them into <path>/etc/modules.autoload.d/kernel-2.6</path> along with any
136 parameters you wanted to pass to them. In baselayout-2, this file is not used
137 anymore. Instead, autoloaded modules and module parameters are placed in one
138 file, <path>/etc/conf.d/modules</path>, no matter the kernel version.
139 </p>
140
141 <p>
142 An example old style configuration would be:
143 </p>
144
145 <pre caption="/etc/modules.autoload.d/kernel-2.6">
146 ivtv
147 cx88_dvb video_br=2
148 </pre>
149
150 <p>
151 Converting the above example would result in the following:
152 </p>
153
154 <pre caption="/etc/conf.d/modules">
155 <comment># Modules autoloaded at boot</comment>
156 modules_2_6="ivtv cx88_dvb"
157 <comment># Module parameters</comment>
158 module_cx88_dvb_args_2_6="video_br=2"
159 </pre>
160
161 <p>
162 In the above examples, the modules and their parameters would only be passed
163 to 2.6.x series kernels. The new configuration allows for fine grained
164 control over the modules and parameters based on kernel version.
165 </p>
166
167 <p>
168 An in-depth example would be:
169 </p>
170
171 <pre caption="detailed example of /etc/conf.d/modules">
172 <comment># Always load ochi1394 and ieee1394, no matter the kernel version</comment>
173 modules="ohci1394 ieee1394"
174 <comment># Only load tun and usbserial for 2.6.x series kernels</comment>
175 modules_2_6="tun usbserial"
176 <comment># Only load cx88_dvb for 2.6.23 kernels</comment>
177 modules_2_6_23="cx88_dvb"
178 <comment># Only load ivtv for 2.6.23-gentoo-r5</comment>
179 modules_2_6_23_gentoo_r5="ivtv"
180
181 <comment># For 2.6.23-gentoo-r5, pass video_br=2 to cx88_dvb</comment>
182 module_cx88_dvb_args_2_6_23_gentoo_r5="video_br=2"
183 <comment># For 2.6.x series kernels, always pass vendor and product</comment>
184 module_usbserial_args_2_6="vendor=0x1410 product=0x2110"
185 <comment># Always pass debug to ieee1394</comment>
186 module_ieee1394_args="debug"
187 </pre>
188
189 <note>
190 Please note the difference between <b>module_</b> and <b>modules_</b>.
191 </note>
192
193 </body>
194 </section>
195 <section id="boot">
196 <title>Boot runlevel</title>
197 <body>
198
199 <p>
200 The <c>boot</c> runlevel performs several important steps for every machine. For
201 example, making sure your root filesystem is mounted read/write, that your
202 filesystems are checked for errors, that your mountpoints are available, and
203 that the <path>/proc</path> pseudo-filesystem is started at boot.
204 </p>
205
206 <p>
207 With OpenRC, volume management services for your block storage devices are no
208 longer run automatically at boot. This includes lvm, raid, swap, device-mapper
209 (dm), dm-crypt, evms, and the like. You must ensure the appropriate initscript
210 for these services is in the <c>boot</c> runlevel, otherwise it's possible that
211 your system will not boot!
212 </p>
213
214 <p>
215 While the OpenRC ebuild will attempt to do this migration for you, you should
216 verify that it migrated all the volume management services properly:
217 </p>
218
219 <pre caption="Display all services in boot runlevel">
220 # <i>ls -l /etc/runlevels/boot/</i>
221 </pre>
222
223 <p>
224 If you don't see root, procfs, mtab, swap, and fsck in the above listing,
225 perform the following to add them to the <c>boot</c> runlevel:
226 </p>
227
228 <pre caption="Adding critical services to the boot runlevel">
229 # <i>rc-update add root boot</i>
230 # <i>rc-update add procfs boot</i>
231 # <i>rc-update add mtab boot</i>
232 # <i>rc-update add fsck boot</i>
233 # <i>rc-update add swap boot</i>
234 </pre>
235
236 <p>
237 If you know you use mdraid and lvm but do not see them above, you would run
238 the following to add initscripts to the <c>boot</c> runlevel:
239 </p>
240
241 <pre caption="Adding mdraid and lvm to the boot runlevel">
242 # <i>rc-update add mdraid boot</i>
243 # <i>rc-update add lvm boot</i>
244 </pre>
245
246 </body>
247 </section>
248 <section>
249 <title>Udev</title>
250 <body>
251
252 <p>
253 OpenRC no longer starts <c>udev</c> by default, but it does need to be present
254 in the <c>sysinit</c> runlevel to be started. The OpenRC ebuild should detect if
255 <c>udev</c> was previously enabled and add it to the <c>sysinit</c> runlevel.
256 However, to be safe, check if <c>udev</c> is present:
257 </p>
258
259 <pre caption="Verifying udev">
260 # <i>ls -l /etc/runlevels/sysinit</i>
261 lrwxrwxrwx 1 root root 14 2009-01-29 08:00 /etc/runlevels/sysinit/udev -> \
262 /etc/init.d/udev
263 </pre>
264
265 <p>
266 If <c>udev</c> is not listed, add it to the correct runlevel:
267 </p>
268
269 <pre caption="Adding udev to the sysinit runlevel">
270 # <i>rc-update add udev sysinit</i>
271 </pre>
272
273 </body>
274 </section>
275 <section>
276 <title>Network</title>
277 <body>
278
279 <p>
280 Due to baselayout and OpenRC being broken into two different packages, your
281 net.eth0 initscript may disappear during the upgrade process. To replace this
282 initscript please perform the following:
283 </p>
284
285 <pre caption="Adding back missing net.eth0 script">
286 # <i>cd /etc/init.d</i>
287 # <i>ln -s net.lo net.eth0</i>
288 </pre>
289
290 <p>
291 If you are missing any other network initscripts, follow the instructions above
292 to re-add them. Simply replace <c>eth0</c> with the name of your network
293 device.
294 </p>
295
296 <p>
297 Also, <path>/etc/conf.d/net</path> no longer uses bash-style arrays for
298 configuration. Please review
299 <path>/usr/share/doc/openrc-&lt;version&gt;/net.example</path> for configuration
300 instructions. Conversion should be relatively straight-forward, for example a
301 static IP assignment would change as follows:
302 </p>
303
304 <pre caption="Old /etc/conf.d/net style">
305 config_eth0=( "192.168.1.37 netmask 255.255.255.0 brd 192.168.1.255" )
306 routes_eth0=( "default via 192.168.1.100" )
307 </pre>
308
309 <pre caption="New /etc/conf.d/net style">
310 config_eth0="192.168.1.37 netmask 255.255.255.0 brd 192.168.1.255"
311 routes_eth0="default via 192.168.1.100"
312 </pre>
313
314 </body>
315 </section>
316 <section>
317 <title>Clock</title>
318 <body>
319
320 <p>
321 Clock settings have been renamed from <path>/etc/conf.d/clock</path> to your
322 system's native tool for adjusting the clock. This means on Linux it will be
323 <path>/etc/conf.d/hwclock</path> and on FreeBSD it will be
324 <path>/etc/conf.d/adjkerntz</path>. Systems without a working real time clock
325 (RTC) chip should use <path>/etc/init.d/swclock</path>, which sets the system
326 time based on the mtime of a file which is created at system shutdown. The
327 initscripts in <path>/etc/init.d/</path> have also been renamed accordingly, so
328 make sure the appropriate script for your system has been added to the boot
329 runlevel.
330 </p>
331
332 <p>
333 Additionally, the <c>TIMEZONE</c> variable is no longer in this file. Its
334 contents are instead found in the <path>/etc/timezone</path> file. If it
335 doesn't exist, you will of course have to create it with your timezone. Please
336 review both of these files to ensure their correctness.
337 </p>
338
339 <p>
340 The proper value for this file is the path relative to your timezone from
341 <path>/usr/share/zoneinfo</path>. For example, for someone living on the east
342 coast of the United States, the following would be a correct setting:
343 </p>
344
345 <pre caption="/etc/timezone">
346 America/New_York
347 </pre>
348
349 </body>
350 </section>
351 <section>
352 <title>XSESSION</title>
353 <body>
354
355 <p>
356 The XSESSION variable is no longer found in <path>/etc/rc.conf</path>. Instead,
357 you can set the XSESSION variable per-user in <path>~/.bashrc</path> (or
358 equivalent), or system-wide in <path>/etc/env.d/</path>.
359 </p>
360
361 <p>
362 Here's an example of setting XSESSION for the whole system:
363 </p>
364
365 <pre caption="Setting XSESSION system-wide">
366 # <i>echo 'XSESSION="Xfce4"' > /etc/env.d/90xsession</i>
367 </pre>
368
369 <impo>
370 You must run <c>env-update</c> after creating a file in <path>/etc/env.d</path>,
371 and then logout and login for it to take effect. If you set the variable in
372 <path>~/.bashrc</path>, you can re-source the file with <c>source
373 ~/.bashrc</c>.
374 </impo>
375
376 </body>
377 </section>
378 <section>
379 <title>EDITOR and PAGER</title>
380 <body>
381
382 <p>
383 The EDITOR variable is no longer found in <path>/etc/rc.conf</path>. Both
384 EDITOR and PAGER are set by default in <path>/etc/profile</path>. You should
385 change this as needed in your <path>~/.bashrc</path> (or equivalent) file or
386 create <path>/etc/env.d/99editor</path> and set the system default there.
387 </p>
388
389 <impo>
390 You must run <c>env-update</c> after creating a file in <path>/etc/env.d</path>,
391 and then logout and login for it to take effect. If you set the variable in
392 <path>~/.bashrc</path>, you can re-source the file with <c>source
393 ~/.bashrc</c>.
394 </impo>
395
396 </body>
397 </section>
398 <section>
399 <title>Boot log</title>
400 <body>
401
402 <p>
403 Previously, you could log the boot process by using
404 <c>app-admin/showconsole</c>. However, OpenRC now handles all logging
405 internally, so there's no need for the hacks that <c>showconsole</c> employed.
406 You can safely unmerge <c>showconsole</c>. To continue logging boot messages,
407 just set the appropriate variable in <path>/etc/rc.conf</path>. Logs will appear
408 in <path>/var/log/rc.log</path>.
409 </p>
410
411 <pre caption="Enabling boot logging in /etc/rc.conf">
412 rc_logger="YES"
413 </pre>
414
415 </body>
416 </section>
417 <section>
418 <title>Finishing up</title>
419 <body>
420
421 <p>
422 Once you've finished updating your config files and initscripts, the last thing
423 to do is <b>reboot</b>. This is necessary because system state information is
424 not preserved during the upgrade, so you'll need to provide it with a fresh
425 boot.
426 </p>
427
428 </body>
429 </section>
430 </chapter>
431 </guide>

  ViewVC Help
Powered by ViewVC 1.1.20