/[gentoo]/xml/htdocs/doc/en/handbook/hb-install-ppc-disk.xml
Gentoo

Contents of /xml/htdocs/doc/en/handbook/hb-install-ppc-disk.xml

Parent Directory Parent Directory | Revision Log Revision Log


Revision 1.4 - (show annotations) (download) (as text)
Sun Apr 4 19:41:25 2004 UTC (10 years, 5 months ago) by pylon
Branch: MAIN
Changes since 1.3: +18 -6 lines
File MIME type: application/xml
Clearified the instructions about the bootstrap-partition.  There were many
users who still not understood that boot-strap != /boot.

Furthermore we need to bind-mount /dev into the chroot, so that yabootconfig
works.  See bug #44924.

1 <?xml version='1.0' encoding='UTF-8'?>
2 <!DOCTYPE sections SYSTEM "/dtd/book.dtd">
3
4 <!-- The content of this document is licensed under the CC-BY-SA license -->
5 <!-- See http://creativecommons.org/licenses/by-sa/1.0 -->
6
7 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/handbook/hb-install-ppc-disk.xml,v 1.3 2004/04/03 08:37:01 bennyc Exp $ -->
8
9 <sections>
10 <section>
11 <title>Introduction to Block Devices</title>
12 <subsection>
13 <title>Block Devices</title>
14 <body>
15
16 <p>
17 We'll take a good look at disk-oriented aspects of Gentoo Linux
18 and Linux in general, including Linux filesystems, partitions and block devices.
19 Then, once you're familiar with the ins and outs of disks and filesystems,
20 you'll be guided through the process of setting up partitions and filesystems
21 for your Gentoo Linux installation.
22 </p>
23
24 <p>
25 To begin, we'll introduce <e>block devices</e>. The most famous block device is
26 probably the one that represents the first IDE drive in a Linux system, namely
27 <path>/dev/hda</path>. If your system uses SCSI drives, then your first hard
28 drive would be <path>/dev/sda</path>.
29 </p>
30
31 <p>
32 The block devices above represent an abstract interface to the disk. User
33 programs can use these block devices to interact with your disk without worrying
34 about whether your drives are IDE, SCSI or something else. The program can
35 simply address the storage on the disk as a bunch of contiguous,
36 randomly-accessible 512-byte blocks.
37 </p>
38
39 </body>
40 </subsection>
41 <subsection>
42 <title>Partitions and Slices</title>
43 <body>
44
45 <p>
46 Although it is theoretically possible to use a full disk to house your Linux
47 system, this is almost never done in practice. Instead, full disk block devices
48 are split up in smaller, more manageable block devices. On most systems,
49 these are called <e>partitions</e>. Other architectures use a similar technique,
50 called <e>slices</e>.
51 </p>
52
53 </body>
54 </subsection>
55 </section>
56 <section>
57 <title>Designing a Partitioning Scheme</title>
58 <subsection>
59 <title>Default Partitioning Scheme</title>
60 <body>
61
62 <p>
63 If you are not interested in drawing up a partitioning scheme for your system,
64 you can use the partitioning scheme we use throughout this book:
65 </p>
66
67 <table>
68 <tr>
69 <th>Partition NewWorld</th>
70 <th>Partition OldWorld</th>
71 <th>Filesystem</th>
72 <th>Size</th>
73 <th>Description</th>
74 </tr>
75 <tr>
76 <ti><path>/dev/hda1</path></ti>
77 <ti>(Not needed)</ti>
78 <ti>(bootstrap)</ti>
79 <ti>800k</ti>
80 <ti>Apple_Bootstrap</ti>
81 </tr>
82 <tr>
83 <ti><path>/dev/hda2</path></ti>
84 <ti><path>/dev/hda1</path></ti>
85 <ti>(swap)</ti>
86 <ti>512M</ti>
87 <ti>Swap partition</ti>
88 </tr>
89 <tr>
90 <ti><path>/dev/hda3</path></ti>
91 <ti><path>/dev/hda2</path></ti>
92 <ti>ext3</ti>
93 <ti>Rest of the disk</ti>
94 <ti>Root partition</ti>
95 </tr>
96 </table>
97
98 <p>
99 If you are interested in knowing how big a partition should be, or even how
100 many partitions you need, read on. Otherwise continue now with
101 <uri link="#fdisk">Using fdisk to Partition your Disk</uri>.
102 </p>
103
104 </body>
105 </subsection>
106 <subsection>
107 <title>How Many and How Big?</title>
108 <body>
109
110 <p>
111 The number of partitions is highly dependent on your environment. For instance,
112 if you have lots of users, you will most likely want to have your
113 <path>/home</path> separate as it increases security and makes backups easier.
114 If you are installing Gentoo to perform as a mailserver, your
115 <path>/var</path> should be separate as all mails are stored inside
116 <path>/var</path>. A good choice of filesystem will then maximise your
117 performance. Gameservers will have a separate <path>/opt</path> as most gaming
118 servers are installed there. The reason is similar for <path>/home</path>:
119 security and backups.
120 </p>
121
122 <p>
123 As you can see, it very much depends on what you want to achieve. Separate
124 partitions or volumes have the following advantages:
125 </p>
126
127 <ul>
128 <li>
129 You can choose the most performant filesystem for each partition or volume
130 </li>
131 <li>
132 Your entire system cannot run out of free space if one defunct tool is
133 continuously writing files to a partition or volume
134 </li>
135 <li>
136 If necessary, file system checks are reduced in time, as multiple checks can
137 be done in parallel (although this advantage is more with multiple disks than
138 it is with multiple partitions)
139 </li>
140 <li>
141 Security can be enhanced by mounting some partitions or volumes read-only,
142 nosuid (setuid bits are ignored), noexec (executable bits are ignored) etc.
143 </li>
144 </ul>
145
146 <p>
147 However, multiple partitions have one big disadvantage: if not configured
148 properly, you might result in having a system with lots
149 of free space on one partition and none on another.
150 </p>
151
152 </body>
153 </subsection>
154 </section>
155 <section id="fdisk">
156 <title>Using mac-fdisk on PPC to Partition your Disk</title>
157 <body>
158
159 <p>
160 At this point, create your partitions using <c>mac-fdisk</c>:
161 </p>
162
163 <pre caption="Starting mac-fdisk">
164 # <i>mac-fdisk /dev/hda</i>
165 </pre>
166
167 <p>
168 First delete the partitions you have cleared previously to make room for your
169 Linux partitions. Use <c>d</c> in <c>mac-fdisk</c> to delete those partition(s).
170 It will ask for the partition number to delete.
171 </p>
172
173 <p>
174 Second, create an <e>Apple_Bootstrap</e> partition by using <c>b</c>. It will
175 ask for what block you want to start. Enter the number of your first free
176 partition, followed by a <c>p</c>. For instance this is <c>3p</c>.
177 </p>
178
179 <note>
180 This partition is <e>not</e> a "boot" partition. It is not used by Linux at all;
181 you don't have to place any filesystem on it and you should never mount it. PPC
182 users don't need a an extra partition for <path>/boot</path>.
183 </note>
184
185 <p>
186 Now create a swap partition by pressing <c>c</c>. Again <c>mac-fdisk</c> will
187 ask for what block you want to start this partition from. As we used <c>3</c>
188 before to create the Apple_Bootstrap partition, you now have to enter
189 <c>4p</c>. When you're asked for the size, enter <c>512M</c> (or whatever size
190 you want -- 512MB is recommended though). When asked for a name, enter <c>swap</c>
191 (mandatory).
192 </p>
193
194 <p>
195 To create the root partition, enter <c>c</c>, followed by <c>5p</c> to select
196 from what block the root partition should start. When asked for the size, enter
197 <c>5p</c> again. <c>mac-fdisk</c> will interpret this as "Use all available
198 space". When asked for the name, enter <c>root</c> (mandatory).
199 </p>
200
201 <p>
202 To finish up, write the partition to the disk using <c>w</c> and <c>q</c> to
203 quit <c>mac-fdisk</c>.
204 </p>
205
206 <p>
207 Now that your partitions are created, you can now continue with <uri
208 link="#filesystems">Creating Filesystems</uri>.
209 </p>
210
211 </body>
212 </section>
213 <section id="filesystems">
214 <title>Creating Filesystems</title>
215 <subsection>
216 <title>Introduction</title>
217 <body>
218
219 <p>
220 Now that your partitions are created, it is time to place a filesystem on them.
221 If you don't care about what filesystem to choose and are happy with what we use
222 as default in this handbook, continue with <uri
223 link="#filesystems-apply">Applying a Filesystem to a Partition</uri>.
224 Otherwise read on to learn about the available filesystems...
225 </p>
226
227 </body>
228 </subsection>
229 <subsection>
230 <title>Filesystems?</title>
231 <body>
232
233 <p>
234 Several filesystems are available. Ext2 and ext3 are found stable on the
235 PPC architecture, reiserfs and xfs are in experimental stage. jfs is
236 unsupported.
237 </p>
238
239 <p>
240 <b>ext2</b> is the tried and true Linux filesystem but doesn't have metadata
241 journaling, which means that routine ext2 filesystem checks at startup time can
242 be quite time-consuming. There is now quite a selection of newer-generation
243 journaled filesystems that can be checked for consistency very quickly and are
244 thus generally preferred over their non-journaled counterparts. Journaled
245 filesystems prevent long delays when you boot your system and your filesystem
246 happens to be in an inconsistent state.
247 </p>
248
249 <p>
250 <b>ext3</b> is the journaled version of the ext2 filesystem, providing metadata
251 journaling for fast recovery in addition to other enhanced journaling modes like
252 full data and ordered data journaling. ext3 is a very good and reliable
253 filesystem. It has an additional hashed b-tree indexing option that enables
254 high performance in almost all situations. In short, ext3 is an excellent
255 filesystem.
256 </p>
257
258 <p>
259 <b>ReiserFS</b> is a B*-tree based filesystem that has very good overall
260 performance and greatly outperforms both ext2 and ext3 when dealing with small
261 files (files less than 4k), often by a factor of 10x-15x. ReiserFS also scales
262 extremely well and has metadata journaling. As of kernel 2.4.18+, ReiserFS is
263 solid and usable as both general-purpose filesystem and for extreme cases such
264 as the creation of large filesystems, the use of many small files, very large
265 files and directories containing tens of thousands of files.
266 </p>
267
268 <p>
269 <b>XFS</b> is a filesystem with metadata journaling that is fully supported
270 under Gentoo Linux's xfs-sources kernel. It comes with a robust feature-set and
271 is optimized for scalability. We only recommend using this filesystem on Linux
272 systems with high-end SCSI and/or fibre channel storage and a uninterruptible
273 power supply. Because XFS aggressively caches in-transit data in RAM, improperly
274 designed programs (those that don't take proper precautions when writing files
275 to disk and there are quite a few of them) can lose a good deal of data if the
276 system goes down unexpectedly.
277 </p>
278
279 <p>
280 <b>JFS</b> is IBM's high-performance journaling filesystem. It has recently
281 become production-ready and there hasn't been a sufficient track record to
282 comment positively nor negatively on its general stability at this point.
283 </p>
284
285 </body>
286 </subsection>
287 <subsection id="filesystems-apply">
288 <title>Applying a Filesystem to a Partition</title>
289 <body>
290
291 <p>
292 To create a filesystem on a partition or volume, there are tools available for
293 each possible filesystem:
294 </p>
295
296 <table>
297 <tr>
298 <th>Filesystem</th>
299 <th>Creation Command</th>
300 </tr>
301 <tr>
302 <ti>ext2</ti>
303 <ti><c>mke2fs</c></ti>
304 </tr>
305 <tr>
306 <ti>ext3</ti>
307 <ti><c>mke2fs -j</c></ti>
308 </tr>
309 <tr>
310 <ti>reiserfs</ti>
311 <ti><c>mkreiserfs</c></ti>
312 </tr>
313 <tr>
314 <ti>xfs</ti>
315 <ti><c>mkfs.xfs</c></ti>
316 </tr>
317 <tr>
318 <ti>jfs</ti>
319 <ti><c>mkfs.jfs</c></ti>
320 </tr>
321 </table>
322
323 <p>
324 For instance, to have the root partition (<path>/dev/hda3</path> in our example)
325 in ext3 (as in our example), you would use:
326 </p>
327
328 <pre caption="Applying a filesystem on a partition">
329 # <i>mke2fs -j /dev/hda3</i>
330 </pre>
331
332 <p>
333 Now create the filesystems on your newly created partitions (or logical
334 volumes).
335 </p>
336
337 </body>
338 </subsection>
339 <subsection>
340 <title>Activating the Swap Partition</title>
341 <body>
342
343 <p>
344 <c>mkswap</c> is the command that is used to initialize swap partitions:
345 </p>
346
347 <pre caption="Creating a Swap signature">
348 # <i>mkswap /dev/hda4</i>
349 </pre>
350
351 <p>
352 To activate the swap partition, use <c>swapon</c>:
353 </p>
354
355 <pre caption="Activating the swap partition">
356 # <i>swapon /dev/hda4</i>
357 </pre>
358
359 <p>
360 Create and activate the swap now.
361 </p>
362
363 </body>
364 </subsection>
365 </section>
366 <section>
367 <title>Mounting</title>
368 <body>
369
370 <p>
371 Now that your partitions are initialized and are housing a filesystem, it is
372 time to mount those partitions. Use the <c>mount</c> command. Don't forget to
373 create the necessary mount directories for every partition you created. As an
374 example we create a mount-point and mount the root and boot partition:
375 </p>
376
377 <pre caption="Mounting partitions">
378 # <i>mkdir /mnt/gentoo</i>
379 # <i>mount /dev/hda3 /mnt/gentoo</i>
380 </pre>
381
382 <note>
383 If you want your <path>/tmp</path> to reside on a separate partition, be sure to
384 change its permissions after mounting: <c>chmod 1777 /mnt/gentoo/tmp</c>. This
385 also holds for <path>/var/tmp</path>.
386 </note>
387
388 <p>
389 We also need to mount the proc filesystem (a virtual interface with the kernel)
390 on <path>/proc</path>. We first create the <path>/mnt/gentoo/proc</path>
391 mountpoint and then mount the filesystem:
392 </p>
393
394 <pre caption="Creating the /mnt/gentoo/proc mountpoint">
395 # <i>mkdir /mnt/gentoo/proc</i>
396 # <i>mount -t proc none /mnt/gentoo/proc</i>
397 </pre>
398
399 <p>
400 Finally we have to create the <path>/dev</path> files in our new home, which is
401 needed during the bootloader installation. This could be done by "bind"-mapping
402 the <path>/dev</path>-filesystem from the LiveCD:
403 </p>
404
405 <pre caption="Bind-mounting the /dev-filesystem">
406 # <i>mkdir /mnt/gentoo/dev</i>
407 # <i>mount -o bind /dev /mnt/gentoo/dev</i>
408 </pre>
409
410 <p>
411 Now continue with <uri link="?part=1&amp;chap=5">Installing the Gentoo
412 Installation Files</uri>.
413 </p>
414
415 </body>
416 </section>
417 </sections>

  ViewVC Help
Powered by ViewVC 1.1.20