Adding a kernel to grub

titaniumdecoy · 12-30-2008, 01:53 AM

I have compiled a kernel from source and am trying to boot with it. (I am using Ubuntu 8.10.) I added a new entry to my grub file by copying a working entry. A snippet of my /boot/grub/menu.lst file is show below.

Code:

# DEFAULT WORKING ENTRY
title		Ubuntu 8.10, kernel 2.6.27-9-generic
uuid		778cb529-8914-451a-97ee-fb2d8ae404ae
kernel		/boot/vmlinuz-2.6.27-9-generic root=UUID=778cb529-8914-451a-97ee-fb2d8ae404ae ro quiet splash 
initrd		/boot/initrd.img-2.6.27-9-generic
quiet

# CUSTOM ADDED ENTRY
title		Custom Kernel
uuid		778cb529-8914-451a-97ee-fb2d8ae404ae
kernel		/boot/bzImage root=UUID=778cb529-8914-451a-97ee-fb2d8ae404ae
ro quiet splash 
initrd		/boot/initramfs
quiet

bzImage is my compiled kernel. I created the initramfs file via the command mkinitramfs -o initramfs `uname -r`.

When I select the custom kernel from the grub boot menu, it outputs a bunch of text and eventually outputs the following:

Code:

WARNING: Couldn't open directory /lib/modules/2.6.28: No such file or directory
FATAL: Could not open /lib/modules/2.6.28/modules.dep.temp for writing: No such file or directory
...
Begin: Waiting for root file system... ... 
...
Done.
Gave up waiting for root device.  Common problems:
...
ALERT! /dev/disk/by-uuid/778cb529-8914-451a-97ee-fb2d8ae404ae does not exist.  Dropping to a shell!

BusyBox v1.10.2. (Ubuntu 1:1.10.2-1ubuntu6) built-in shell (ash)
...

(initramfs) _

My guess is that either:
1) I configured the grub file incorrectly
2) The initramfs file was not properly created

Please help! Thanks in advance.

clvic · 12-30-2008, 11:28 AM

It seems like your ramfs was made without the "device mapper" support, that loads the module dm-mod.ko. You can solve by creating the ramfs file with the right options (I don't know the exact option as I use mkinitrd), or by compiling the device mapper into the kernel itself, not as a module

titaniumdecoy · 12-30-2008, 11:45 AM

Thanks clvic, that is very helpful.

What options do you use for mkinitrd? And do you know what the name of the kernel option is? Thanks.

EDIT: I believe the config option is Device Drivers -> Multi-device support (RAID and LVM) ->
Device mapper support.

EDIT: Can someone tell me the options for mkinitrd to create an initrd with device mapper support?

titaniumdecoy · 12-30-2008, 01:46 PM

I recompiled the kernel with Device mapper support enabled (via the config option in my previous post) and I get a similar message.

Is there another option I need to use to enable device mapping? Or could someone enlighten me as to how to create an initramfs with support for device mapping? Thanks.

EDIT: I don't know if it's relevant but I always get this error before the others when I try to boot:
[ 1.6787027] alg: cipher: Test 1 failed on encryption for aes-asm

Quakeboy02 · 12-30-2008, 02:02 PM

Since you're using Ubuntu, you should be using this methodology to compile and install a kernel:

http://www.howtoforge.com/kernel_compilation_ubuntu

dpkg -i will install it in menu.lst

titaniumdecoy · 12-30-2008, 02:10 PM

@Quakeboy02: Thanks, I have spent so long on this method already though I want to give it another shot.

I gave up on using the UUID in grub. So now I have this in my /boot/grub/menu.lst file:

Code:

title		kernel 2.6.28
root		(hd0,0)
kernel		/boot/vmlinuz-2.6.28 root=/dev/sda1
initrd		/boot/initrd.img-2.6.28

I am getting the same errors. Are my values correct (ie, the (hd0,0) and /dev/sda1)? The contents of my /etc/fstab file are below:

Code:

# /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults        0       0
# /dev/sda1
UUID=778cb529-8914-451a-97ee-fb2d8ae404ae /               ext3    relatime,errors=remount-ro 0       1
# /dev/sda5
UUID=31169659-b1a0-4192-91f4-7d65b4f74655 none            swap    sw              0       0
/dev/scd0       /media/cdrom0   udf,iso9660 user,noauto,exec,utf8 0       0
# Beginning of the block added by the VMware software
.host:/                 /mnt/hgfs               vmhgfs  defaults,ttl=5     0 0
# End of the block added by the VMware software

It really is this poorly formatted.

Quakeboy02 · 12-30-2008, 02:41 PM

Quote:

Originally Posted by titaniumdecoy

@Quakeboy02: Thanks, I have spent so long on this method already though I want to give it another shot.

Suit yourself, but using the Ubuntu (Debian) method, there are very few steps that you have to take.

Quote:

I gave up on using the UUID in grub. So now I have this in my /boot/grub/menu.lst file:

Code:

title		kernel 2.6.28
root		(hd0,0)
kernel		/boot/vmlinuz-2.6.28 root=/dev/sda1
initrd		/boot/initrd.img-2.6.28

Here are the entries in my menu.lst file for 2.6.28. I'm not sure if your issue is that "ro" is missing or not. I have no way of knowing if you added a suffix; in my case "-k8". What is the actual directory name in /lib/modules?

Code:

title           Debian GNU/Linux, kernel 2.6.28-k8
root            (hd0,0)
kernel          /boot/vmlinuz-2.6.28-k8 root=/dev/sda1 ro
initrd          /boot/initrd.img-2.6.28-k8

title           Debian GNU/Linux, kernel 2.6.28-k8 (single-user mode)
root            (hd0,0)
kernel          /boot/vmlinuz-2.6.28-k8 root=/dev/sda1 ro single
initrd          /boot/initrd.img-2.6.28-k8

titaniumdecoy · 12-31-2008, 01:00 AM

I tried the method suggested by Quakeboy02. I wiped the system to make sure the old kernel was not in the way. I let the Ubuntu (Debian) package system take care of everything for me. In the end, I got the exact same error. I am using defconfig which includes device mapper support.

Any ideas? Thanks in advance.

Quakeboy02 · 12-31-2008, 12:21 PM

Are you saying that you used "dpkg -i" to install the new kernel ".deb" file and got the same grub problem?

titaniumdecoy · 12-31-2008, 01:35 PM

Quote:

Originally Posted by Quakeboy02

Are you saying that you used "dpkg -i" to install the new kernel ".deb" file and got the same grub problem?

Yes, that is what I am saying.

Quakeboy02 · 12-31-2008, 03:20 PM

Quote:

Originally Posted by titaniumdecoy

Yes, that is what I am saying.

OK, can I see the exact command that you used to compile your kernel, as well as the entire contents of your menu.lst file in a code block?

titaniumdecoy · 01-01-2009, 03:12 AM

I finally got it working. I changed the following values in my .config file although I'm not sure which was/were responsible for making it work:

Code:

CONFIG_FUSION=y
CONFIG_FUSION_SPI=y
CONFIG_SCSI=y
CONFIG_SCSI_NETLINK=y
CONFIG_BLK_DEV_SD=y
CONFIG_CHR_DEV_ST=y
CONFIG_SCSI_SPI_ATTRS=y
CONFIG_SCSI_FC_ATTRS=y
CONFIG_SCSI_ISCSI_ATTRS=y
CONFIG_SCSI_SAS_ATTRS=y

Thanks, Quakeboy02, for all your help.

Quakeboy02 · 01-01-2009, 11:19 AM

Glad you got it working! I wish I knew exactly what was wrong. I saw one with similar issues not too long ago, and it was Ubuntu, as well. I suspect that it was the CONFIG_SCSI line that fixed it, but the problem most likely relates somehow to initrd, like you said in your first post. On Debian I am able to get away with CONFIG_SCSI=m.

Anyway, Happy New Year, and have fun!

alcarola · 04-16-2010, 01:57 AM

Thanks, that solved my problem!

I'm almost sure the crucial one is CONFIG_BLK_DEV_SD=y. That was the case for me at least.

You get a hint by looking för sd in dmesg.