How do I boot up In Grub2 If It is using grub legacy now ?

OBnascar · #1 10-19-2009, 12:32 PM

I have Sidux installed on sda1 (hd0,1) and Parsix 3.0 on sdb1 (hd1,1).

Sidux uses grub legacy and Parsix Grub2. I had sidux installed but just recently added Parsix 3.0 and put grub2 on the root partition. Sidux grub is also installed on the root partition.

After I got done installing Parsix my computer still boots up using grub legacy from the sidux partition.

Is there a way to to get it to use grub2 from the Parsix partition ? I used to do this with the Grub Super Disk but I guess it does not recognize grub2. I have searched and read many-many doc's and articles on grub2 but have not found anything yet on what I am trying to accomplish.

**saikee** · #2 10-20-2009, 05:34 PM

That depends on whether you have used Ext4 as the filing system for Parsix.

If you do then Grub legacy will not be able to boot it directly but with indirect booting (using chainloading) both Grub legacy and Grub2 can boot every OP installed in a PC.

According to your description that Grub2 has been installed in its root partition (hd1,1) then it should be bootable by legacy Grub and the booting commands should be

Code:

title Parsix in (hd1,1)
root (hd1,1)
chainloader +1

If this is the case and your Parsix can be booted up then you can install Grub2 in the MBR of first disk using this command in the root terminal of Parsix

Code:

grub-install /dev/sda

Yes the above command is same as lagacy Grub but Grub2 while count zero for the disk number has switched to counting from one for the partition number. It should call your Parsix partition (hd1,2) now. The above is among the few that is common to both versions of Grub.

Hope the above helps. This thread may be of interest to you. More details are available from GNU/Grub Wiki.

OBnascar · #3 10-20-2009, 06:53 PM

Quote:

Originally Posted by saikee

That depends on whether you have used Ext4 as the filing system for Parsix..

No, I am using ext3.

Quote:

If this is the case and your Parsix can be booted up then you can install Grub2 in the MBR of first disk using this command in the root terminal of Parsix

Code:

grub-install /dev/sda

Yes Parsix boots up fine without chainloader, I just direct booted from the kernel by creating my own Parsix grub entry in the grub legacy menu.lst.

Do you think it would also work if I installed Grub2 to partition instead of the mbr ?

Code:

grub-install /dev/sda1

Otherwise I will try to the mbr as you suggest.

Thank you saikee for the link to your very well written Grub2 thread. I will save that in my Grub2 info library. And thank you for your comments and suggestions. I will post back later with my results.

**saikee** · #4 10-21-2009, 04:31 PM

Quote:

Do you think it would also work if I installed Grub2 to partition instead of the mbr ?

Yep either version of Grub can chainload the other.

Grub can't read many OS filing systems can chainload all of them. The famous example is NTFS filing systen used by MS Windows.

OBnascar · #5 10-22-2009, 10:19 AM

I was able to use a Grub2 boot loader menu on my computer instead of the grub legacy menu that I was booting up, it was easier than I thought.

First I booted into the partition that had Grub2 installed, then in a terminal:

Code:

# grub-install /dev/sd?

sd? would be the drive where I have grub2 installed. Then the next time I booted up l was seeing the Grub2 boot loader menu instead of the menu from my other Linux distro that was using grub legacy. This is what I was trying to accomplish.

To make all of my other Linux distros show up in my Grub2 boot loader menu, again I booted into the partition where my Grub2 was installed and then entered:

Code:

# os-prober
# update-grub2

When "update-grub2" is executed, Grub 2 will read /etc/default/grub and the files in contained in the /etc/grub.d folder. This combination will set the visual parameters of the grub menu (/etc/default/grub) and search for linux kernels, other operating systems, and items designated in user-created scripts in /etc/grub.d.

I rebooted and my new Grub2 boot loader menu showed all of my other Linux distros on this computer.

**saikee** · #6 10-22-2009, 01:44 PM

Yep GRub2 does offer an edge on a few areas but it no longer has the equivalent "geometry" command and simple things like "grub-install /dev/fd0" no longer works.