[SOLVED] Booting LFS 7.0 with grub2

ubuntudude12 · 12-30-2011, 05:19 PM

Hi,

I am currently using Ubuntu 11.10. I have just finished my first Linux From Scratch build, and now I am trying to make it bootable. My system currently has Grub2 installed. I am trying to figure out how to add an entry for Linux from Scratch to Grub2. The partitions I am using are /dev/sd5 (the root partition), /dev/sda6 (the boot partition), /dev/sda7 (the home partition), and /dev/sda8 (the swap partition). Does anyone know how to do this?

-Aaron

spiky0011 · 12-30-2011, 05:30 PM

Hi

The 1st thing can you post your /etc/fstab file and grub.cfg also the output of

Code:

sudo fdisk -l

.
It also depends on how you want to boot the system, mine is kept seperate from ubuntu

ubuntudude12 · 12-30-2011, 06:13 PM

Hi,

The output of sudo fdisk -l is:

Code:

Disk /dev/sda: 200.0 GB, 200049647616 bytes
255 heads, 63 sectors/track, 24321 cylinders, total 390721968 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00003f4a


   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048   207154828   103576390+  83  Linux
/dev/sda2       207157246   253292543    23067649    5  Extended
/dev/sda5       207157248   228128767    10485760   83  Linux
/dev/sda6       228130816   228325375       97280   83  Linux
/dev/sda7       228327424   249098239    10385408   83  Linux
/dev/sda8       249100288   253292543     2096128   82  Linux swap / Solaris

The /ect/fstab file for my host system (Ubuntu) is the following:

Code:

# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    nodev,noexec,nosuid 0       0
# / was on /dev/sda1 during installation
UUID=2b04dc66-c2b2-4e25-ac01-5a3936372264 /               ext4    errors=remount-ro 0       1
# swap was on /dev/sda8 during installation
UUID=6067c5ee-0a8e-4c79-ad79-fd9743808f1f none            swap    sw              0       0

My LFS's /ect/fstab file is as follows:

Code:

# Begin /etc/fstab

# file system  mount-point  type  options         dump  fsck
#                                                       order

/dev/sda5      /            ext3 defaults         1     1
/dev/sda6      /boot        ext3 defaults         0     0
/dev/sda8      swap         swap pri=1            0     0
proc           /proc        proc defaults         0     0
sysfs          /sys         sysfs defaults        0     0
devpts         /dev/pts     devpts gid=4,mode=620 0     0
tmpfs          /run         tmpfs defaults        0     0
# End /ect/fstab

-Aaron

Roken · 12-30-2011, 06:16 PM

I had to add an entry to /etc/grub.d/40_custom for grub 2:

Code:

menuentry "Linux 3.1-roken" {
	savedefault
	insmod ext2
	set root='(hd0,1)'
        linux   /vmlinuz-3.1.roken root=/dev/sdb3 ro radeon.modeset=0 vga=795
}

You would obviously need to change the "linux" line to fit your system and make sure that root is set correctly.

Then

Code:

sudo update-grub

ubuntudude12 · 12-30-2011, 08:22 PM

I tried your suggestion, modifying the linux line to the proper settings for my system. When I try to boot using Grub2, I receive an error saying that the disk was not found, Do you know what could cause this?

-Aaron

Roken · 12-30-2011, 09:02 PM

It may be your set root= line - double and triple check that. There can also be problems if you built the kernel incorrectly. Does it get so far into the boot before it bombs, and if so what is the actual text of the error produced?

spiky0011 · 12-31-2011, 01:08 AM

Post your grub.cfg how you set it up this time, and the error message you get

druuna · 12-31-2011, 02:31 AM

Hi,

Am I assuming correctly that you are using the grub that came with Ubuntu and not the one mewntioned/build/configured in LFS?

With that assumption in mind: Doesn't running a grub-update from Ubuntu find the new LFS system?

One of my other systems runs Debian (very related to Ubuntu) and running grub-update does find other OS's installed. On Debian this is the way to do it. If you manually add entries to grub (grub.cfg to be exact) they might be removed when the grub package is updated.

Have a look here (especially 6 Adding Entries to Grub 2): Ubuntu - the Grub 2 guide

If you do need to do this manually I believe the entry should look like this:

Code:

menuentry "LFS 7.0 - linux 3.1.5" {
   insmod ext2
   set    root=(hd0,6)
   linux  /vmlinuz-3.1.5-lfs-7.0  root=/dev/sda5  ro
}

- the set root=(...) entry should point to your boot partition,
- the root=/dev/... entry points to your root partition.

Hope this helps.

ubuntudude12 · 12-31-2011, 07:19 AM

Thank you druuna! I tried out your suggestion, and it worked! Thank you for all of the help you provided me.

Roken · 12-31-2011, 07:23 AM

Quote:

Originally Posted by druuna

If you manually add entries to grub (grub.cfg to be exact) they might be removed when the grub package is updated.

Just as a matter of interest, this is why I suggested in including the entry in 40_custom, which ensures that it gets added back in after a grub update.

druuna · 12-31-2011, 07:36 AM

Hi,

Quote:

Originally Posted by ubuntudude12

Thank you druuna! I tried out your suggestion, and it worked! Thank you for all of the help you provided me.

You're welcome

zoelee4 · 09-12-2016, 07:14 PM

I tried doing what you said and it did not work. I am using ubuntu 14 in a VM and LFS 7.8. here is the output of sudo fdisk -l:

Click image for larger version

Name: Screen Shot 2016-09-12 at 5.09.50 PM.png
Views: 50
Size: 147.9 KB
ID: 22991

(its an image because its a VM).

Here is what the "/etc/grub.d/40_custom" looks like:

Click image for larger version

Name: Screen Shot 2016-09-12 at 5.12.49 PM.png
Views: 43
Size: 55.1 KB
ID: 22992

Thanks for your help in advance and sorry for the noob question.