doc/en/grub-error-guide.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/grub-error-guide.xml,v 1.17 2011/09/04 17:53:40 swift Exp $ -->

<guide>
<title>Gentoo Grub Error Collection</title>

<author title="Thread Reviewer">Hartwig Brandl</author>
<author title="Editor">
  <mail link="deathwing00@gentoo.org">Ioannis Aslanidis</mail>
</author>
<author title="Editor">
  <mail link="swift@gentoo.org">Sven Vermeulen</mail>
</author>

<abstract>
The objective of this error collection is to list the GRUB problems and errors
people can be facing. All these solutions have been acquired through the
cooperation of many users of the Gentoo Forums.
</abstract>

<!-- The content of this document is licensed under the CC-BY-SA license -->
<!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
<license/>

<version>2</version>
<date>2011-12-26</date>

<chapter>
<title>Starting notes</title>

<section>
<title>Acknowledgements</title>
<body>

<p>
Many thanks to
<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&amp;u=18420">Earthwings</uri>,
<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&amp;u=39305">penetrode</uri>,
<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&amp;u=41638">loyaltonone</uri>,
<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&amp;u=4980">pilla</uri>,
<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&amp;u=3139">airhead</uri>,
<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&amp;u=13816">nephros</uri>,
<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&amp;u=25859">yamakawa</uri>
and all the others for the suggestions on the original
<uri link="http://forums.gentoo.org/viewtopic.php?t=122656">thread</uri>.
</p>

</body>
</section>

<section>
<title>Disclaimer warning</title>
<body>

<p>
The examples provided are just examples. Be sure to change partition numbers
and the like according to your systems specs. Follow the solutions provided
by this document at your own risk.
</p>

</body>
</section>
</chapter>

<chapter>
<title>Grub loading, please wait...</title>
<section>
<title>Situation</title>
<body>

<pre caption="Grub output">
GRUB loading stage 1.5
GRUB loading, please wait...
</pre>

<p>
After this message, the system stops. If you attempt to boot the system using a
grub floppy, the problem disappears.
</p>

</body>
</section>
<section>
<title>Solution</title>
<body>

<p>
According to
<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&amp;u=3134">The_Bell</uri>
you could change the boot order in your BIOS.
</p>

<p>
Tell your BIOS to not boot from your floppy first.
</p>

<p>
<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&amp;u=39305">penetrode</uri>
wrote that this may also be due to bad CFLAGS settings.
Although the current grub ebuild filters out <c>-fstack-protector</c>, it can't
hurt to recompile grub with clean CFLAGS if nothing else helps.
</p>

<pre caption="Using a clean CFLAG to rebuild GRUB">
# <i>CFLAGS="-O2 -march=i686 -fomit-frame-pointer -pipe" emerge grub</i>
</pre>

</body>
</section>
</chapter>

<chapter>
<title>Grub Error 12</title>
<section>
<title>Situation</title>
<body>

<pre caption="Grub Output">
12 : Invalid device requested.
</pre>

<p>
This error is returned if the device strings syntax is correct but other than
that, an error occurred that isn't defined by any other error.
</p>

</body>
</section>
<section>
<title>Solution</title>
<body>

<p>
When you installed grub in your boot record using the interactive commands,
did you execute the two lines below in the grub prompt?
</p>

<pre caption="Interactive installation commands">
grub&gt; <i>root (hd0,0)</i>
grub&gt; <i>setup (hd0)</i>
</pre>

<p>
(hd0,0) must be replaced with your boot partition and (hd0) with the HDD
you have chosen. Remember that (hd0) will install the bootloader in the
Master Boot Record of the first hard disk, the primary master.
</p>

</body>
</section>
</chapter>

<chapter>
<title>Grub Error 15</title>
<section>
<title>Situation</title>
<body>

<p>
This error can occur in two different stages of the GRUB configuration, either
during the initial configuration (installing GRUB in the master boot record) or
after booting the system and attempting to launch Linux (or any other entry).
</p>

<pre caption="Grub Output - Initial Configuration">
grub&gt; <i>root (hd0,0)</i>
 Filesystem type is xfs, partition type 0x83

grub&gt; <i>setup (hd0)</i>
 Checking if "/boot/grub/stage1" exists... no
 Checking if "/grub/stage1" exists... no

Error 15: File not found
</pre>

<pre caption="Grub Output - Booting an Entry">
Booting 'gentoo Linux'

root (hd0,0)
Filesystem type is ext2fs, partition type 0x83
kernel (hd0,0)/boot/kernel-2.4.20 root=/dev/sda3 vga=792

Error 15: File not found
Press any key to continue...
</pre>

</body>
</section>
<section>
<title>Solution - Initial Configuration</title>
<body>

<p>
This error is returned if the specified file name cannot be found, but
everything else (like the disk/partition info) is OK.
</p>

<p>
Frequently, the error notes a missing kernel image file. Make sure that
the file it is referring to exists on your boot partition.
</p>

<p>
To find out the exact name of your kernel, boot from the installation cd, mount
your root and (if applicable) boot partition. Next, chroot into your Gentoo
system and do a listing of the available files to see what kernel images you
have available:
</p>

<pre caption="Verifying kernel image existence">
# <i>cd /boot</i>
# <i>ls</i>
</pre>

<p>
This will list all the kernels that you've got on your boot partition.
If your kernel is missing make sure that you compiled a kernel (using
<c>genkernel</c> or manually):
</p>

<pre caption="Recompile the kernel">
# <i>cd /usr/src/linux/</i>
# <i>make menuconfig</i>
# <i>make</i>
</pre>

<p>
And that you copied it to your boot partition:
</p>

<pre caption="Copying the kernel">
# <i>cp /usr/src/linux/arch/i386/boot/bzImage /boot</i>
</pre>

<p>
Verify that the name of the kernel is exactly the same as the one mentioned in
your <path>grub.conf</path> file. Also make sure that the <c>kernel</c> line in
your <path>grub.conf</path> file is referring to that partition (either
explicitly or implicitly).
</p>

<p>
Another reported mistake is to have the BIOS ignore the disk on which the kernel
or grub stages reside. Also, the partition on which grub stores its stages
should not use a software RAID-5 (or other striping technology) configuration.
</p>

</body>
</section>
<section>
<title>Solution - Booting an Entry</title>
<body>

<p>
First, verify that the <c>root</c> and <c>setup</c> lines you have used are
correct.
</p>

<p>
If you are certain they are valid, then you <e>might</e> be using a flawed GRUB
version (0.93.20031222). Upgrade your Portage tree or mask this version of
grub:
</p>

<pre caption="Masking Grub">
<comment>(Execute this from within the chrooted environment)</comment>
# <i>echo "=sys-boot/grub-0.93.20031222" &gt;&gt; /etc/portage/package.mask</i>
# <i>emerge grub -p</i>
</pre>

<p>
You could also try to use the <c>grub-install</c> script as is recommended by
the GRUB authors:
</p>

<pre caption="Using grub-install">
<comment>(The --root-directory is needed if you are using a separate boot
partition,
 otherwise you should leave it out)</comment>
# <i>grub-install --root-directory=/boot /dev/sda</i>
</pre>

<p>
When all this fails, your boot partition may be corrupt. Check the partition for
errors:
</p>

<pre caption="Checking a partition for errors">
<comment>(Make sure the boot partition, /dev/sda1 in this case, is unmounted)</comment>
# <i>fsck -y /dev/sda1</i>
</pre>

</body>
</section>
</chapter>

<chapter>
<title>Grub Error 17</title>
<section>
<title>Situation</title>
<body>

<pre caption="Grub Output">
root (hd0,0)
filesystem type unknown partition type 0x7

Error 17 : Cannot mount selected partition
</pre>

</body>
</section>
<section>
<title>Solution</title>
<body>

<p>
This error is returned if the partition requested exists, but the
filesystem type cannot be recognized by GRUB.
</p>

<p>
Be sure to check your root(x,y) settings in your grub.conf.
</p>

<p>
Also, if you are trying to boot Windows, make sure that your
<path>grub.conf</path> file has the <c>root (hdX,Y)</c> (or <c>rootnoverify
(hdX,Y)</c>) and <c>chainloader (hdX,Y)+1</c> in it.
</p>

</body>
</section>
</chapter>

<chapter>
<title>Grub Error 18</title>
<section>
<title>Situation</title>
<body>

<pre caption="Grub Output">
kernel (hd1,4)/bzImage root=/dev/sdb7

Error 18: Selected cylinder exceeds max supported by BIOS
</pre>

</body>
</section>
<section>
<title>Solution</title>
<body>

<p>
This error is returned when a read is attempted at a linear block address beyond
the end of the BIOS translated area. This generally happens if your
disk is larger than the BIOS can handle (512MB for (E)IDE disks on
older machines or larger than 8GB in general).
</p>

<p>
Try an update for your BIOS and/or move your boot partition to the
front (or at least into the appropriate range).
</p>

</body>
</section>
</chapter>

<chapter>
<title>GRUB GRUB GRUB GRUB GRUB ...</title>
<section>
<title>Situation</title>
<body>

<pre caption="Grub Output">
GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB
  GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB
...
</pre>

</body>
</section>
<section>
<title>Solution</title>
<body>

<p>
According to
<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&amp;u=3139">airhead</uri>
this can be caused by having your bios detect your disks automatically. Try to
set your bios entry to User Type HDD.
</p>

<p>
Another possibility is that you had Grub installed on your MBR and tried
reinstalling it (for instance due to hard disk changes) but used the wrong
<c>setup</c> and <c>root</c> commands.
</p>

</body>
</section>
</chapter>

<chapter>
<title>Probing Devices to Guess BIOS Drives. This May Take a Long Time.</title>
<section>
<title>Situation</title>
<body>

<p>
While trying to install grub, it hangs after displaying the following line:
</p>

<pre caption="Grub Output">
# <i>grub</i>

Probing devices to guess BIOS drives. This may take a long time.
</pre>

</body>
</section>
<section>
<title>Solution</title>
<body>

<p>
One reported cause was an exotic configuration of disk devices, like
ultra/non-ultra DMA disks on one cable.
</p>

</body>
</section>
</chapter>

<chapter>
<title>When Installing Grub, It Just Hangs</title>
<section>
<title>Situation</title>
<body>

<p>
When installing grub, it hangs:
</p>

<pre caption="Grub Output">
# <i>grub</i>
<comment>(At this stage, the installation stops)</comment>
</pre>

</body>
</section>
<section>
<title>Solution</title>
<body>

<p>
If you haven't got a floppy drive, have you used the --no-floppy switch?
</p>

<pre caption="Installing grub using the --no-floppy switch">
# <i>grub --no-floppy</i>
</pre>

</body>
</section>
</chapter>

<chapter>
<title>Uncompressing Linux... Ok, booting the kernel.</title>
<section>
<title>Situation</title>
<body>

<p>
The system hangs after displaying the following line:
</p>

<pre caption="Linux Output">
Uncompressing Linux... Ok, booting the kernel.
</pre>

</body>
</section>
<section>
<title>Solution</title>
<body>

<p>
Strictly speaking, this is no grub error. One possible cause is that ACPI is
not working correctly but is enabled in the kernel. Try to disable it in your
bios or in your kernel.
</p>

</body>
</section>
</chapter>

<chapter>
<title>Grub Just Shows a Grub Prompt</title>
<section>
<title>Situation</title>
<body>

<p>
When booting the system, you receive a grub prompt instead of a list of entries
you have defined in your <path>grub.conf</path> file.
</p>

</body>
</section>
<section>
<title>Solution</title>
<body>

<p>
Mount your boot partition and verify if the <path>grub/grub.conf</path> file
exists.
</p>

<pre caption="Mounting and verifying">
# <i>mount /dev/sda1 /mnt/gentoo/boot</i>
# <i>cat /mnt/gentoo/boot/grub/grub.conf</i>
</pre>

<p>
Also make sure that the <path>menu.lst</path> symbolic link exists:
</p>

<pre caption="Verifying the symbolic link">
# <i>ls -l /mnt/gentoo/boot/grub/menu.lst</i>
lrwxrwxrwx  1 root root 9 Mar  7 14:00 /mnt/gentoo/boot/grub/menu.lst -> grub.conf
</pre>

<p>
If not, recreate the symbolic link:
</p>

<pre caption="Recreating the menu.lst symbolic link">
# <i>cd /mnt/gentoo/boot/grub</i>
# <i>ln -snf grub.conf menu.lst</i>
</pre>

<p>
If this is the case, reinstall grub:
</p>

<pre caption="Reinstalling Grub">
<comment>(Run from within the chrooted environment)</comment>
# <i>grub-install --root-directory=/boot /dev/sda</i>
</pre>

</body>
</section>
</chapter>

<chapter>
<title>Could Not Find Device For /boot/boot: Not Found Or Not a Block Device</title>
<section>
<title>Situation</title>
<body>

<p>
When running <c>grub-install</c> during the GRUB installation, you receive the
following error:
</p>

<pre caption="Grub Output">
# <i>grub-install --root-directory=/boot /dev/sda</i>
Could not find device for /boot/boot: not found or not a block device
</pre>

</body>
</section>
<section>
<title>Solution</title>
<body>

<p>
Check that you didn't forget the following:
</p>

<pre caption="Updating the mtab file">
# <i>grep -v rootfs /proc/mounts > /etc/mtab</i>
</pre>

</body>
</section>
</chapter>

<chapter>
<title>The System Reboots After Hitting Return At The Grub Menu</title>
<section>
<title>Situation</title>
<body>

<p>
After hitting Return at the Grub menu during the system boot, the system
reboots.
</p>

</body>
</section>
<section>
<title>Solution</title>
<body>

<p>
Try disabling framebuffer support in your kernel.
If this does not help, disable APM and ACPI.
</p>

</body>
</section>
</chapter>

<chapter>
<title>After Hitting Return At The Grub Menu, The Screen Blanks Out</title>
<section>
<title>Situation</title>
<body>

<p>
After hitting Return at the Grub menu during system boot, the screen blanks out,
but the system is responsive (for instance, your numlock led is switcheable).
</p>

</body>
</section>
<section>
<title>Solution</title>
<body>

<p>
Turn off framebuffer (typically remove <c>vga=XYZ</c> from your
<path>grub.conf</path>) and check the processor architecture in your
kernel config.
</p>

</body>
</section>
</chapter>

<chapter>
<title>Missing Grub Image</title>
<section>
<title>Situation</title>
<body>

<p>
When booting the system, you do not see that spify Gentoo splashscreen.
</p>

</body>
</section>
<section>
<title>Solution</title>
<body>

<p>
First of all check if the splashscreen file you are referring to in your
<path>grub.conf</path> really exists. If that is the case, go and check
the grub ebuild. Maybe the patch for the splash image is commented out in the
version that you are using.
</p>

</body>
</section>
</chapter>

<chapter>
<title>Failing To Boot Windows From a Second Harddrive</title>
<section>
<title>Situation</title>
<body>

<p>
After selecting the Windows entry, the system refuses to boot without any clear
reason as to why.
</p>

</body>
</section>
<section>
<title>Solution</title>
<body>

<p>
<uri
link="http://forums.gentoo.org/profile.php?mode=viewprofile&amp;u=14595">cyrillic</uri>
informed us that you can "map" your disks in a different order by changing your
<path>grub.conf</path>'s Windows entry like so:
</p>

<pre caption="Mapping disks">
title Windows XP
  map (hd0) (hd1)
  map (hd1) (hd0)
  chainloader (hd1,0)+1
</pre>

</body>
</section>
</chapter>

<chapter>
<title>Grub segfaults when trying to install</title>
<section>
<title>Situation</title>
<body>

<p>
The situation described below is only relevant for grub-0.95.x at the moment
of installing grub at the boot sector.
</p>

<pre caption="Installing Grub">
grub&gt; root (hd0,0)

grub&gt; setup (hd0)

Segmentation fault
</pre>

</body>
</section>
<section>
<title>Solution</title>
<body>

<p>
This is a known bug related to this problem and has been fixed
in grub 0.96. It is also known that grub 0.94 r1 and grub 0.94 r2
should work correctly. If that fails too, you can try to emerge
grub-static which is currently stable on amd64 and unstable on x86
(~x86). Check out bug
<uri link="http://bugs.gentoo.org/show_bug.cgi?id=79378">#79378</uri>
for additional information.
</p>

</body>
</section>
</chapter>

</guide>
1	<?xml version="1.0" encoding="UTF-8"?>
2	<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
3	<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/grub-error-guide.xml,v 1.17 2011/09/04 17:53:40 swift Exp $ -->
4
5	<guide>
6	<title>Gentoo Grub Error Collection</title>
7
8	<author title="Thread Reviewer">Hartwig Brandl</author>
9	<author title="Editor">
10	<mail link="deathwing00@gentoo.org">Ioannis Aslanidis</mail>
11	</author>
12	<author title="Editor">
13	<mail link="swift@gentoo.org">Sven Vermeulen</mail>
14	</author>
15
16	<abstract>
17	The objective of this error collection is to list the GRUB problems and errors
18	people can be facing. All these solutions have been acquired through the
19	cooperation of many users of the Gentoo Forums.
20	</abstract>
21
22	<!-- The content of this document is licensed under the CC-BY-SA license -->
23	<!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
24	<license/>
25
26	<version>2</version>
27	<date>2011-12-26</date>
28
29	<chapter>
30	<title>Starting notes</title>
31
32	<section>
33	<title>Acknowledgements</title>
34	<body>
35
36	<p>
37	Many thanks to
38	<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&u=18420">Earthwings</uri>,
39	<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&u=39305">penetrode</uri>,
40	<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&u=41638">loyaltonone</uri>,
41	<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&u=4980">pilla</uri>,
42	<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&u=3139">airhead</uri>,
43	<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&u=13816">nephros</uri>,
44	<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&u=25859">yamakawa</uri>
45	and all the others for the suggestions on the original
46	<uri link="http://forums.gentoo.org/viewtopic.php?t=122656">thread</uri>.
47	</p>
48
49	</body>
50	</section>
51
52	<section>
53	<title>Disclaimer warning</title>
54	<body>
55
56	<p>
57	The examples provided are just examples. Be sure to change partition numbers
58	and the like according to your systems specs. Follow the solutions provided
59	by this document at your own risk.
60	</p>
61
62	</body>
63	</section>
64	</chapter>
65
66	<chapter>
67	<title>Grub loading, please wait...</title>
68	<section>
69	<title>Situation</title>
70	<body>
71
72	<pre caption="Grub output">
73	GRUB loading stage 1.5
74	GRUB loading, please wait...
75	</pre>
76
77	<p>
78	After this message, the system stops. If you attempt to boot the system using a
79	grub floppy, the problem disappears.
80	</p>
81
82	</body>
83	</section>
84	<section>
85	<title>Solution</title>
86	<body>
87
88	<p>
89	According to
90	<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&u=3134">The_Bell</uri>
91	you could change the boot order in your BIOS.
92	</p>
93
94	<p>
95	Tell your BIOS to not boot from your floppy first.
96	</p>
97
98	<p>
99	<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&u=39305">penetrode</uri>
100	wrote that this may also be due to bad CFLAGS settings.
101	Although the current grub ebuild filters out <c>-fstack-protector</c>, it can't
102	hurt to recompile grub with clean CFLAGS if nothing else helps.
103	</p>
104
105	<pre caption="Using a clean CFLAG to rebuild GRUB">
106	# <i>CFLAGS="-O2 -march=i686 -fomit-frame-pointer -pipe" emerge grub</i>
107	</pre>
108
109	</body>
110	</section>
111	</chapter>
112
113	<chapter>
114	<title>Grub Error 12</title>
115	<section>
116	<title>Situation</title>
117	<body>
118
119	<pre caption="Grub Output">
120	12 : Invalid device requested.
121	</pre>
122
123	<p>
124	This error is returned if the device strings syntax is correct but other than
125	that, an error occurred that isn't defined by any other error.
126	</p>
127
128	</body>
129	</section>
130	<section>
131	<title>Solution</title>
132	<body>
133
134	<p>
135	When you installed grub in your boot record using the interactive commands,
136	did you execute the two lines below in the grub prompt?
137	</p>
138
139	<pre caption="Interactive installation commands">
140	grub> <i>root (hd0,0)</i>
141	grub> <i>setup (hd0)</i>
142	</pre>
143
144	<p>
145	(hd0,0) must be replaced with your boot partition and (hd0) with the HDD
146	you have chosen. Remember that (hd0) will install the bootloader in the
147	Master Boot Record of the first hard disk, the primary master.
148	</p>
149
150	</body>
151	</section>
152	</chapter>
153
154	<chapter>
155	<title>Grub Error 15</title>
156	<section>
157	<title>Situation</title>
158	<body>
159
160	<p>
161	This error can occur in two different stages of the GRUB configuration, either
162	during the initial configuration (installing GRUB in the master boot record) or
163	after booting the system and attempting to launch Linux (or any other entry).
164	</p>
165
166	<pre caption="Grub Output - Initial Configuration">
167	grub> <i>root (hd0,0)</i>
168	Filesystem type is xfs, partition type 0x83
169
170	grub> <i>setup (hd0)</i>
171	Checking if "/boot/grub/stage1" exists... no
172	Checking if "/grub/stage1" exists... no
173
174	Error 15: File not found
175	</pre>
176
177	<pre caption="Grub Output - Booting an Entry">
178	Booting 'gentoo Linux'
179
180	root (hd0,0)
181	Filesystem type is ext2fs, partition type 0x83
182	kernel (hd0,0)/boot/kernel-2.4.20 root=/dev/sda3 vga=792
183
184	Error 15: File not found
185	Press any key to continue...
186	</pre>
187
188	</body>
189	</section>
190	<section>
191	<title>Solution - Initial Configuration</title>
192	<body>
193
194	<p>
195	This error is returned if the specified file name cannot be found, but
196	everything else (like the disk/partition info) is OK.
197	</p>
198
199	<p>
200	Frequently, the error notes a missing kernel image file. Make sure that
201	the file it is referring to exists on your boot partition.
202	</p>
203
204	<p>
205	To find out the exact name of your kernel, boot from the installation cd, mount
206	your root and (if applicable) boot partition. Next, chroot into your Gentoo
207	system and do a listing of the available files to see what kernel images you
208	have available:
209	</p>
210
211	<pre caption="Verifying kernel image existence">
212	# <i>cd /boot</i>
213	# <i>ls</i>
214	</pre>
215
216	<p>
217	This will list all the kernels that you've got on your boot partition.
218	If your kernel is missing make sure that you compiled a kernel (using
219	<c>genkernel</c> or manually):
220	</p>
221
222	<pre caption="Recompile the kernel">
223	# <i>cd /usr/src/linux/</i>
224	# <i>make menuconfig</i>
225	# <i>make</i>
226	</pre>
227
228	<p>
229	And that you copied it to your boot partition:
230	</p>
231
232	<pre caption="Copying the kernel">
233	# <i>cp /usr/src/linux/arch/i386/boot/bzImage /boot</i>
234	</pre>
235
236	<p>
237	Verify that the name of the kernel is exactly the same as the one mentioned in
238	your <path>grub.conf</path> file. Also make sure that the <c>kernel</c> line in
239	your <path>grub.conf</path> file is referring to that partition (either
240	explicitly or implicitly).
241	</p>
242
243	<p>
244	Another reported mistake is to have the BIOS ignore the disk on which the kernel
245	or grub stages reside. Also, the partition on which grub stores its stages
246	should not use a software RAID-5 (or other striping technology) configuration.
247	</p>
248
249	</body>
250	</section>
251	<section>
252	<title>Solution - Booting an Entry</title>
253	<body>
254
255	<p>
256	First, verify that the <c>root</c> and <c>setup</c> lines you have used are
257	correct.
258	</p>
259
260	<p>
261	If you are certain they are valid, then you <e>might</e> be using a flawed GRUB
262	version (0.93.20031222). Upgrade your Portage tree or mask this version of
263	grub:
264	</p>
265
266	<pre caption="Masking Grub">
267	<comment>(Execute this from within the chrooted environment)</comment>
268	# <i>echo "=sys-boot/grub-0.93.20031222" >> /etc/portage/package.mask</i>
269	# <i>emerge grub -p</i>
270	</pre>
271
272	<p>
273	You could also try to use the <c>grub-install</c> script as is recommended by
274	the GRUB authors:
275	</p>
276
277	<pre caption="Using grub-install">
278	<comment>(The --root-directory is needed if you are using a separate boot
279	partition,
280	otherwise you should leave it out)</comment>
281	# <i>grub-install --root-directory=/boot /dev/sda</i>
282	</pre>
283
284	<p>
285	When all this fails, your boot partition may be corrupt. Check the partition for
286	errors:
287	</p>
288
289	<pre caption="Checking a partition for errors">
290	<comment>(Make sure the boot partition, /dev/sda1 in this case, is unmounted)</comment>
291	# <i>fsck -y /dev/sda1</i>
292	</pre>
293
294	</body>
295	</section>
296	</chapter>
297
298	<chapter>
299	<title>Grub Error 17</title>
300	<section>
301	<title>Situation</title>
302	<body>
303
304	<pre caption="Grub Output">
305	root (hd0,0)
306	filesystem type unknown partition type 0x7
307
308	Error 17 : Cannot mount selected partition
309	</pre>
310
311	</body>
312	</section>
313	<section>
314	<title>Solution</title>
315	<body>
316
317	<p>
318	This error is returned if the partition requested exists, but the
319	filesystem type cannot be recognized by GRUB.
320	</p>
321
322	<p>
323	Be sure to check your root(x,y) settings in your grub.conf.
324	</p>
325
326	<p>
327	Also, if you are trying to boot Windows, make sure that your
328	<path>grub.conf</path> file has the <c>root (hdX,Y)</c> (or <c>rootnoverify
329	(hdX,Y)</c>) and <c>chainloader (hdX,Y)+1</c> in it.
330	</p>
331
332	</body>
333	</section>
334	</chapter>
335
336	<chapter>
337	<title>Grub Error 18</title>
338	<section>
339	<title>Situation</title>
340	<body>
341
342	<pre caption="Grub Output">
343	kernel (hd1,4)/bzImage root=/dev/sdb7
344
345	Error 18: Selected cylinder exceeds max supported by BIOS
346	</pre>
347
348	</body>
349	</section>
350	<section>
351	<title>Solution</title>
352	<body>
353
354	<p>
355	This error is returned when a read is attempted at a linear block address beyond
356	the end of the BIOS translated area. This generally happens if your
357	disk is larger than the BIOS can handle (512MB for (E)IDE disks on
358	older machines or larger than 8GB in general).
359	</p>
360
361	<p>
362	Try an update for your BIOS and/or move your boot partition to the
363	front (or at least into the appropriate range).
364	</p>
365
366	</body>
367	</section>
368	</chapter>
369
370	<chapter>
371	<title>GRUB GRUB GRUB GRUB GRUB ...</title>
372	<section>
373	<title>Situation</title>
374	<body>
375
376	<pre caption="Grub Output">
377	GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB
378	GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB GRUB
379	...
380	</pre>
381
382	</body>
383	</section>
384	<section>
385	<title>Solution</title>
386	<body>
387
388	<p>
389	According to
390	<uri link="http://forums.gentoo.org/profile.php?mode=viewprofile&u=3139">airhead</uri>
391	this can be caused by having your bios detect your disks automatically. Try to
392	set your bios entry to User Type HDD.
393	</p>
394
395	<p>
396	Another possibility is that you had Grub installed on your MBR and tried
397	reinstalling it (for instance due to hard disk changes) but used the wrong
398	<c>setup</c> and <c>root</c> commands.
399	</p>
400
401	</body>
402	</section>
403	</chapter>
404
405	<chapter>
406	<title>Probing Devices to Guess BIOS Drives. This May Take a Long Time.</title>
407	<section>
408	<title>Situation</title>
409	<body>
410
411	<p>
412	While trying to install grub, it hangs after displaying the following line:
413	</p>
414
415	<pre caption="Grub Output">
416	# <i>grub</i>
417
418	Probing devices to guess BIOS drives. This may take a long time.
419	</pre>
420
421	</body>
422	</section>
423	<section>
424	<title>Solution</title>
425	<body>
426
427	<p>
428	One reported cause was an exotic configuration of disk devices, like
429	ultra/non-ultra DMA disks on one cable.
430	</p>
431
432	</body>
433	</section>
434	</chapter>
435
436	<chapter>
437	<title>When Installing Grub, It Just Hangs</title>
438	<section>
439	<title>Situation</title>
440	<body>
441
442	<p>
443	When installing grub, it hangs:
444	</p>
445
446	<pre caption="Grub Output">
447	# <i>grub</i>
448	<comment>(At this stage, the installation stops)</comment>
449	</pre>
450
451	</body>
452	</section>
453	<section>
454	<title>Solution</title>
455	<body>
456
457	<p>
458	If you haven't got a floppy drive, have you used the --no-floppy switch?
459	</p>
460
461	<pre caption="Installing grub using the --no-floppy switch">
462	# <i>grub --no-floppy</i>
463	</pre>
464
465	</body>
466	</section>
467	</chapter>
468
469	<chapter>
470	<title>Uncompressing Linux... Ok, booting the kernel.</title>
471	<section>
472	<title>Situation</title>
473	<body>
474
475	<p>
476	The system hangs after displaying the following line:
477	</p>
478
479	<pre caption="Linux Output">
480	Uncompressing Linux... Ok, booting the kernel.
481	</pre>
482
483	</body>
484	</section>
485	<section>
486	<title>Solution</title>
487	<body>
488
489	<p>
490	Strictly speaking, this is no grub error. One possible cause is that ACPI is
491	not working correctly but is enabled in the kernel. Try to disable it in your
492	bios or in your kernel.
493	</p>
494
495	</body>
496	</section>
497	</chapter>
498
499	<chapter>
500	<title>Grub Just Shows a Grub Prompt</title>
501	<section>
502	<title>Situation</title>
503	<body>
504
505	<p>
506	When booting the system, you receive a grub prompt instead of a list of entries
507	you have defined in your <path>grub.conf</path> file.
508	</p>
509
510	</body>
511	</section>
512	<section>
513	<title>Solution</title>
514	<body>
515
516	<p>
517	Mount your boot partition and verify if the <path>grub/grub.conf</path> file
518	exists.
519	</p>
520
521	<pre caption="Mounting and verifying">
522	# <i>mount /dev/sda1 /mnt/gentoo/boot</i>
523	# <i>cat /mnt/gentoo/boot/grub/grub.conf</i>
524	</pre>
525
526	<p>
527	Also make sure that the <path>menu.lst</path> symbolic link exists:
528	</p>
529
530	<pre caption="Verifying the symbolic link">
531	# <i>ls -l /mnt/gentoo/boot/grub/menu.lst</i>
532	lrwxrwxrwx 1 root root 9 Mar 7 14:00 /mnt/gentoo/boot/grub/menu.lst -> grub.conf
533	</pre>
534
535	<p>
536	If not, recreate the symbolic link:
537	</p>
538
539	<pre caption="Recreating the menu.lst symbolic link">
540	# <i>cd /mnt/gentoo/boot/grub</i>
541	# <i>ln -snf grub.conf menu.lst</i>
542	</pre>
543
544	<p>
545	If this is the case, reinstall grub:
546	</p>
547
548	<pre caption="Reinstalling Grub">
549	<comment>(Run from within the chrooted environment)</comment>
550	# <i>grub-install --root-directory=/boot /dev/sda</i>
551	</pre>
552
553	</body>
554	</section>
555	</chapter>
556
557	<chapter>
558	<title>Could Not Find Device For /boot/boot: Not Found Or Not a Block Device</title>
559	<section>
560	<title>Situation</title>
561	<body>
562
563	<p>
564	When running <c>grub-install</c> during the GRUB installation, you receive the
565	following error:
566	</p>
567
568	<pre caption="Grub Output">
569	# <i>grub-install --root-directory=/boot /dev/sda</i>
570	Could not find device for /boot/boot: not found or not a block device
571	</pre>
572
573	</body>
574	</section>
575	<section>
576	<title>Solution</title>
577	<body>
578
579	<p>
580	Check that you didn't forget the following:
581	</p>
582
583	<pre caption="Updating the mtab file">
584	# <i>grep -v rootfs /proc/mounts > /etc/mtab</i>
585	</pre>
586
587	</body>
588	</section>
589	</chapter>
590
591	<chapter>
592	<title>The System Reboots After Hitting Return At The Grub Menu</title>
593	<section>
594	<title>Situation</title>
595	<body>
596
597	<p>
598	After hitting Return at the Grub menu during the system boot, the system
599	reboots.
600	</p>
601
602	</body>
603	</section>
604	<section>
605	<title>Solution</title>
606	<body>
607
608	<p>
609	Try disabling framebuffer support in your kernel.
610	If this does not help, disable APM and ACPI.
611	</p>
612
613	</body>
614	</section>
615	</chapter>
616
617	<chapter>
618	<title>After Hitting Return At The Grub Menu, The Screen Blanks Out</title>
619	<section>
620	<title>Situation</title>
621	<body>
622
623	<p>
624	After hitting Return at the Grub menu during system boot, the screen blanks out,
625	but the system is responsive (for instance, your numlock led is switcheable).
626	</p>
627
628	</body>
629	</section>
630	<section>
631	<title>Solution</title>
632	<body>
633
634	<p>
635	Turn off framebuffer (typically remove <c>vga=XYZ</c> from your
636	<path>grub.conf</path>) and check the processor architecture in your
637	kernel config.
638	</p>
639
640	</body>
641	</section>
642	</chapter>
643
644	<chapter>
645	<title>Missing Grub Image</title>
646	<section>
647	<title>Situation</title>
648	<body>
649
650	<p>
651	When booting the system, you do not see that spify Gentoo splashscreen.
652	</p>
653
654	</body>
655	</section>
656	<section>
657	<title>Solution</title>
658	<body>
659
660	<p>
661	First of all check if the splashscreen file you are referring to in your
662	<path>grub.conf</path> really exists. If that is the case, go and check
663	the grub ebuild. Maybe the patch for the splash image is commented out in the
664	version that you are using.
665	</p>
666
667	</body>
668	</section>
669	</chapter>
670
671	<chapter>
672	<title>Failing To Boot Windows From a Second Harddrive</title>
673	<section>
674	<title>Situation</title>
675	<body>
676
677	<p>
678	After selecting the Windows entry, the system refuses to boot without any clear
679	reason as to why.
680	</p>
681
682	</body>
683	</section>
684	<section>
685	<title>Solution</title>
686	<body>
687
688	<p>
689	<uri
690	link="http://forums.gentoo.org/profile.php?mode=viewprofile&u=14595">cyrillic</uri>
691	informed us that you can "map" your disks in a different order by changing your
692	<path>grub.conf</path>'s Windows entry like so:
693	</p>
694
695	<pre caption="Mapping disks">
696	title Windows XP
697	map (hd0) (hd1)
698	map (hd1) (hd0)
699	chainloader (hd1,0)+1
700	</pre>
701
702	</body>
703	</section>
704	</chapter>
705
706	<chapter>
707	<title>Grub segfaults when trying to install</title>
708	<section>
709	<title>Situation</title>
710	<body>
711
712	<p>
713	The situation described below is only relevant for grub-0.95.x at the moment
714	of installing grub at the boot sector.
715	</p>
716
717	<pre caption="Installing Grub">
718	grub> root (hd0,0)
719
720	grub> setup (hd0)
721
722	Segmentation fault
723	</pre>
724
725	</body>
726	</section>
727	<section>
728	<title>Solution</title>
729	<body>
730
731	<p>
732	This is a known bug related to this problem and has been fixed
733	in grub 0.96. It is also known that grub 0.94 r1 and grub 0.94 r2
734	should work correctly. If that fails too, you can try to emerge
735	grub-static which is currently stable on amd64 and unstable on x86
736	(~x86). Check out bug
737	<uri link="http://bugs.gentoo.org/show_bug.cgi?id=79378">#79378</uri>
738	for additional information.
739	</p>
740
741	</body>
742	</section>
743	</chapter>
744
745	</guide>