/[gentoo]/xml/htdocs/doc/en/gentoo-x86-tipsntricks.xml
Gentoo

Contents of /xml/htdocs/doc/en/gentoo-x86-tipsntricks.xml

Parent Directory Parent Directory | Revision Log Revision Log


Revision 1.5 - (show annotations) (download) (as text)
Sun Apr 11 15:35:24 2004 UTC (10 years, 8 months ago) by swift
Branch: MAIN
Changes since 1.4: +31 -1 lines
File MIME type: application/xml
#46638 - Adding information on checking the disk for consistency

1 <?xml version='1.0' encoding="UTF-8"?>
2 <!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
3
4 <guide link="/doc/en/gentoo-x86-tipsntricks.xml">
5 <title>Gentoo/x86 Installation Tips &amp; Tricks</title>
6 <author title="Author">
7 <mail link="swift@gentoo.org">Sven Vermeulen</mail>
8 </author>
9
10 <abstract>
11 The Gentoo installation allows for very flexible approaches to the various
12 installation methods. As it is almost impossible to insert every single tip or
13 trick in the installation instructions this document tries to deal with all
14 submitted tips and tricks for reference purposes.
15 </abstract>
16
17 <license/>
18
19 <version>1.2</version>
20 <date>April 11, 2004</date>
21
22 <chapter>
23 <title>Introduction</title>
24 <section>
25 <title>Preliminary</title>
26 <body>
27
28 <p>
29 This document contains various tips and tricks for the Gentoo/x86 installation.
30 Most of them are discussed in a dense way - they are meant as an addendum to the
31 installation instructions and not as a replacement.
32 </p>
33
34 </body>
35 </section>
36 <section>
37 <title>Contents</title>
38 <body>
39
40 <p>
41 <b>Advanced Installations</b>
42 </p>
43
44 <ul>
45 <li><uri link="#software-raid">Software RAID</uri></li>
46 <li><uri link="#ata-raid-2.4">ATA RAID using 2.4 kernels</uri></li>
47 </ul>
48
49 <p>
50 <b>Simplifying the Installation</b>
51 </p>
52
53 <ul>
54 <li><uri link="#leave_terminal">Leaving the Terminal</uri></li>
55 </ul>
56
57 <p>
58 <b>Fixing Errors/Issues</b>
59 </p>
60
61 <ul>
62 <li><uri link="#checking-disks">Extensive Testing of your Disks</uri></li>
63 </ul>
64
65 </body>
66 </section>
67 </chapter>
68 <chapter>
69 <title>Advanced Installations</title>
70 <section id="software-raid">
71 <title>Software RAID</title>
72 <body>
73
74 <note>
75 If you are not known to software raid, please read the <uri
76 link="http://tldp.org/HOWTO/Software-RAID-HOWTO.html">Software-RAID-HOWTO</uri>.
77 </note>
78
79 <p>
80 Once you are booted from the LiveCD, load the appropriate RAID modules. For
81 instance, if you plan on using RAID-1:
82 </p>
83
84 <pre caption="Loading the RAID-1 module">
85 # <i>modprobe raid1</i>
86 </pre>
87
88 <p>
89 When you partition your disks, make sure that your partitions use <c>fd</c>
90 (Linux raid autodetect) as Partition Type instead of <c>83</c> (Linux native).
91 You can alter the partition type using the <c>t</c> command in <c>fdisk</c>.
92 </p>
93
94 <p>
95 After partitioning, create the <path>/etc/raidtab</path> file (yes, indeed, on
96 the LiveCD environment) and insert the necessary commands for your RAID setup.
97 For instance, to have your boot, swap and root partition mirrored (RAID-1)
98 covering <path>/dev/sda</path> and <path>/dev/sdb</path>, you can use:
99 </p>
100
101 <pre caption="/etc/raidtab for RAID-1 setup">
102 raiddev /dev/md0
103 raid-level 1
104 nr-raid-disks 2
105 chunk-size 32
106 persistent-superblock 1
107 device /dev/sda1
108 raid-disk 0
109 device /dev/sdb1
110 raid-disk 1
111
112 raiddev /dev/md1
113 raid-level 1
114 nr-raid-disks 2
115 chunk-size 32
116 persistent-superblock 1
117 device /dev/sda2
118 raid-disk 0
119 device /dev/sdb2
120 raid-disk 1
121
122 raiddev /dev/md2
123 raid-level 1
124 nr-raid-disks 2
125 chunk-size 32
126 persistent-superblock 1
127 device /dev/sda3
128 raid-disk 0
129 device /dev/sdb3
130 raid-disk 1
131 </pre>
132
133 <p>
134 Now create the necessary RAID devices for each RAID device you listed in
135 <path>/etc/raidtab</path>:
136 </p>
137
138 <pre caption="Creating RAID devices">
139 # <i>mkraid /dev/md0</i>
140 # <i>mkraid /dev/md1</i>
141 # <i>mkraid /dev/md2</i>
142 </pre>
143
144 <p>
145 The Linux Software RAID driver will start creating the metadevices. You can see
146 its progress in <path>/proc/mdstat</path>. Wait until the metadevices are
147 completely finished before proceeding.
148 </p>
149
150 <p>
151 From now onwards, use <path>/dev/md0</path> for the boot partition,
152 <path>/dev/md1</path> for the swap partition and <path>/dev/md2</path> for the
153 root partition.
154 </p>
155
156 <p>
157 After mounting <path>/dev/md2</path> on <path>/mnt/gentoo</path>, don't forget
158 to copy over <path>/etc/raidtab</path> to <path>/mnt/gentoo/etc</path>.
159 </p>
160
161 <p>
162 When you're configuring your kernel, make sure you have the appropriate RAID
163 support <e>in</e> your kernel and not as module.
164 </p>
165
166 <p>
167 When installing extra tools, emerge <c>raidtools</c> as well. Note that this
168 isn't available on all LiveCDs so you might not be able to install Gentoo on a
169 Software RAID when using a networkless installation!
170 </p>
171
172 <p>
173 When configuring your bootloader, make sure it gets installed in the MBR of
174 <e>both</e> disks if you use mirroring.
175 </p>
176
177 </body>
178 </section>
179 <section id="ata-raid-2.4">
180 <title>ATA RAID using 2.4 kernels</title>
181 <body>
182
183 <p>
184 Make sure you boot your LiveCD using the <c>doataraid</c> option. Once booted,
185 check the contents of <path>/dev/ataraid</path>. It should contain various
186 <path>disc*</path> directories for each harddisk available in the ATA RAID. An
187 entire disk is displayed as <path>disc</path> while partitions are
188 <path>part*</path>.
189 </p>
190
191 <p>
192 Write down the various <path>/dev/ataraid/disc*/*</path> device files that you
193 use to install Gentoo on. You will need to substitute the <path>/dev/hda</path>
194 examples in the installation with this path.
195 </p>
196
197 <p>
198 Before chrooting, bind-mount the <path>/dev</path> structure in the new
199 environment:
200 </p>
201
202 <pre caption="Bind-mounting /dev">
203 # <i>mount -o bind /dev /mnt/gentoo/dev</i>
204 </pre>
205
206 <p>
207 When configuring your kernel, make sure you enable support for your ATA RAID
208 chipset and options. For instance, a popular ATA RAID system is a <e>Promise
209 FastTrack built-in RAID</e> in which case you definitely need <c>Promise
210 FastTrack Options</c> built in into your kernel.
211 </p>
212
213 <p>
214 When configuring GRUB, you first have to create a GRUB bootdisk. This is not as
215 hard as you think. First install GRUB as you would, but when you come to the
216 part where GRUB is getting installed in the MBR, follow the following
217 instructions:
218 </p>
219
220 <pre caption="Creating a GRUB bootdisk">
221 # <i>cd /boot/grub</i>
222 # <i>dd if=stage1 of=/dev/fd0 bs=512 count=1</i>
223 # <i>dd if=stage2 of=/dev/fd0 bs=512 seek=1</i>
224 </pre>
225
226 <p>
227 You still need to write your <path>grub.conf</path> file. This is no different
228 from the installation instructions, just make sure that your <c>root=</c> points
229 to the ATA RAID device.
230 </p>
231
232 <p>
233 After finishing the installation, boot with your GRUB bootdisk. You will be
234 greeted by a GRUB prompt. Now configure GRUB to boot from the ATA RAID device:
235 </p>
236
237 <pre caption="Installing GRUB on the ATA RAID">
238 grub&gt; root (hd0,x)
239 grub&gt; setup (hd0)
240 grub&gt; quit
241 </pre>
242
243 <p>
244 Now reboot (with the GRUB bootfloppy removed).
245 </p>
246
247 <p>
248 LILO users can safely use the instructions mentioned in the installation
249 instructions.
250 </p>
251
252 </body>
253 </section>
254 </chapter>
255
256 <chapter>
257 <title>Simplifying the Installation</title>
258 <section id="leave_terminal">
259 <title>Leaving your Terminal</title>
260 <body>
261
262 <p>
263 Many people want to leave their system when it's compiling. In certain cases
264 this is rather difficult as the installation is done in a public environment
265 where you cannot trust everyone. If this is the case, you want to be able to
266 perform the compilation in the background and log out from all terminals.
267 </p>
268
269 <p>
270 There are several possible solutions for this. The first one is to use
271 <c>screen</c>. After booting the LiveCD, set your root password and start a
272 screen session:
273 </p>
274
275 <note>
276 Not all LiveCDs provide screen. If this is the case, you will have to use one of
277 the other methods described in this section.
278 </note>
279
280 <pre caption="Starting a screen session">
281 # <i>screen -S gentoo</i>
282 </pre>
283
284 <p>
285 Once inside the screen session you can perform the entire installation. When you
286 want to leave your terminal, press <c>Ctrl-a, d</c> (that is, control and a at
287 the same time, then followed by a d) to <e>detach</e> your screen session. You
288 can now safely log out of your system.
289 </p>
290
291 <p>
292 To regain access to your terminal, log in as root again and <e>attach</e> to
293 the running screen session:
294 </p>
295
296 <pre caption="Attaching to a screen session">
297 # <i>screen -x gentoo</i>
298 </pre>
299
300 <p>
301 If you can't use screen, there is still a way to leave your terminal. Follow the
302 installation instructions, but when you come to the point where a long-term
303 compilation would be started (for instance the <c>./scripts/bootstrap.sh</c>
304 step), use <c>nohup</c> which allows for a process to continue even when you log
305 out. Don't forget the trailing "&amp;", otherwise the process won't be placed in
306 the background! Remember where you are (the <c>pwd</c> command will show you
307 that) as you will need to know this later on.
308 </p>
309
310 <pre caption="Using nohup">
311 # <i>pwd</i>
312 /usr/portage
313 # <i>nohup ./scripts/bootstrap.sh &amp;</i>
314 </pre>
315
316 <p>
317 Now exit the chrooted environment (<c>exit</c>) and the LiveCD session. Your
318 compilation will continue in the background.
319 </p>
320
321 <p>
322 When you want to check the compilation, log in as root (on the LiveCD) and
323 chroot back into your environment and go to the directory where you left off:
324 </p>
325
326 <pre caption="Chrooting back">
327 # <i>chroot /mnt/gentoo /bin/bash</i>
328 # <i>env-update &amp;&amp; source /etc/profile</i>
329 # <i>cd /usr/portage</i>
330 </pre>
331
332 <p>
333 Now use the <c>less</c> command on the <path>nohup.out</path> file that is
334 situated inside that directory. The compilation will append its output to that
335 file, so if you want to follow the compilation progress, run <c>less
336 nohup.out</c> and press <c>F</c> to follow the changes. When the compilation is
337 finished, you can continue with the next step of the installation instructions.
338 </p>
339
340 <p>
341 If you ever get tired of following the changes, press <c>Ctrl-C</c> followed by
342 a <c>q</c>. This won't stop the compilation process, only the <c>less</c>
343 process.
344 </p>
345
346 </body>
347 </section>
348 </chapter>
349
350 <chapter>
351 <title>Fixing Errors/Issues</title>
352 <section id="checking-disks">
353 <title>Extensive Testing of your Disks</title>
354 <body>
355
356 <p>
357 If you think your disk needs to be thoroughly checked for consistency (bad
358 sectors and such), you can use the <c>-c</c> option while placing the ext2 or
359 ext3 filesystem on it (using <c>mke2fs</c>). This will perform a read-test and
360 will mark all bad blocks as such. If you are really paranoid, use <c>-c -c</c>
361 to perform an extensive read/write test.
362 </p>
363
364 <pre caption="Checking for disk consistency">
365 # <i>mke2fs -j -c /dev/hda3</i>
366 </pre>
367
368 </body>
369 </section>
370 </chapter>
371
372 </guide>

  ViewVC Help
Powered by ViewVC 1.1.20