adding new Gentoo install to existing grub2?

[ThunderRd]

I've finally gotten around to building a Gentoo system. This is on my sidux box, where sidux is installed on the primary IDE master. Gentoo is on the slave.

At this point I've accomplished the following, using the minimum install .iso:

-partitioned a /boot (ext2), /home (ext4), /swap, and / (ext4)
-installed the base system using the latest stage 3 archive
-chroot into the new install
-emerged portage and updated
-compiled the kernel (I used the genkernel script, but edited the config file using makeconfig first)
-did the appropriate networking and system configurations
-installed grub to MBR

Basically, I followed the install guide here, to the letter:
Gentoo Linux Documentation -- About the Gentoo Linux Installation

Now, I realize that I probably shouldn't have installed grub, since I'd really rather start Gentoo from the existing grub2 in sidux.

I booted into sidux, and ran update-grub. It seems to recognize that there is a Gentoo install:

Found Gentoo Base System release 1.12.13 on /dev/sdb4

Now, if I understand grub2 correctly, that means that grub would see that location as (hd1,3), which is the / of Gentoo. Now, here is where I'm confused. Should it point to the / file system, or should it point to /boot, which would be (hd1,0)?

I need to get Gentoo added to the grub menu, but grub2 no longer has a menu.lst to edit. Seems that now all edits are to be made within the scripts in /etc/grub.d, specifically in a script named 40_custom. These scripts write to the /etc/boot/grub.cfg file, which creates the boot menu.

I have attached grub.cfg. At the end of the file you can see what 40_custom has written to it.

The bottom line is, the menu entry doesn't work. Grub gives a error that the location does not exist, and Gentoo does not boot. Because of that, I'm not sure if the Gentoo install was successful, and the boot entries are the problem, or if the install is borked somehow, and grub is actually OK. I guess I'm not sure what would be more straightforward: adding Gentoo to the sidux grub2; adding sidux to the Gentoo grub; or chainloading gentoo grub from sidux. There are probably many ways to get it done, but just when I thought I had mastered what I need to know on grub, both deb unstable and sidux moved to this grub2 mess.

(I strongly suspect that the install is good, and I don't know what to do with grub2 :/ )

At this point I'm a bit stuck, so if Kaitain, Gizmo, or another Gentoo veteran can shed some light I'd be much obliged...

[Kaitain]

From within Sidux add this to /etc/grub.d/40_custom/ and set its executable bit:

#!/bin/sh
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries. Simply type the
# menu entries you want to add after this comment. Be careful not to change
# the 'exec tail' line above.

menuentry "Gentoo Linux" {
set root=(hd1,0) 
linux /boot/kernel-2.6.34-gentoo-r1 root=/dev/sdb3
}

and run update-grub.

EDIT:: if you wanted to go the "chainloader +1" route, you'd point it at (hd1,0)

[Kaitain]

When you update your Gentoo kernel in the future, you can chroot into your Sidux partition and use the tools found there in situ. This will save you the hassle of unmasking Gentoo's grub2 ebuild and trying to keep two lots of defaults and custom scripts aligned.

[ThunderRd]

OK, gotcha. There was some confusion re: the partition nomenclature that had me confused, but I think I have a handle on it now. During the install the live media calls the drive /dev/hdb, but after the chroot and the reboot it is called /dev/sdb..which means I have to rewrite fstab & etc. This wasn't documented and it took me a while to figure out why the boot hung while mounting /.

I'll take a look at making those corrections and getting grub going tomorrow. Thanks for cribbing the entry in 40_custom for me, I'm sure I'll have a question or two more so stay tuned

[chrisbard]

Or simply use Windows 7. It's so much simpler and better

[ThunderRd]

Thanks, bard, I'll try that.

[ThunderRd]

My Gentoo project is going quite well. Today I found some time to work on it some more, I recompiled the kernel using the ck-sources available in portage, and made some minor adjustments in there (had a framebuffer error that prevented the nvidia install, now fixed). I have been using the ck/BFS kernel since it arrived last year, and I have said here before that it is very, very quick as a desktop kernel.

With a bit of advice from Kaitain I was able to get sidux booting through Gentoo's grub, which is a whole lot easier for me to manage than the vagaries of grub2.

I also emerged X and Xfce4, and got the nvidia driver successfully installed. Frankly, it was the easiest time I have ever had with the nvidia driver on any distro I have tried. So I have a desktop and it's starting to look like I'll be exploring Gentoo for some time to come.

I have a question for someone in the know. First, I've been working as root so far, so I created a new user, made it a member of group users, and created a user directory using useradd. Then I added a password. But, thunderrd can't seem to obtain root privileges with su. The password entry fails with Permission denied. I'm sure I've missed something here in the creation of the account, what is it?

[Daniel ~]

Come on guys me and TB have been waiting over an hour for an answer...!

( I view theses threads like a Sci-Fi soap opera....you know how that is!!!":O}

[Gizmo]

Originally Posted by ThunderRd

But, thunderrd can't seem to obtain root privileges with su. The password entry fails with Permission denied. I'm sure I've missed something here in the creation of the account, what is it?

You just need to add the thunderrd account to the wheel group. That will then allow thunderrd to su to root.

[ThunderRd]

Thanks, Giz. I figured it was something like that. I probably have to think of what other groups the normal user should be in. I guess cdr and audio, for sure...

[ThunderRd]

Building this Gentoo setup has been going well. I have been a bit tight with time but did manage to get the desktop, all audio and codec stuff I need, some utilities, and office apps all emerged today.

Also, I spent some time with the nvidia/Xorg stuff and got Compiz-Fusion and Emerald going, so it's looking pretty snazzy, too.

I am amazed at the quickness of a system that doesn't have anything in it except what I wanted. BIOS to working Compiz desktop in under 35 seconds, and it simply "feels" nimble; like a car with fairly good horsepower but oodles of torque. That's what makes a good car fun on the street.

sidux is the fastest distro I've used to date by far - but it has a lot of stuff in the base install that isn't used. From what I see so far, Gentoo is even faster.

[Gizmo]

A lot of Linux folks turn up their noses at Gentoo because it's a source distro, and think those of us who actually WANT to compile our own systems are nuts when we talk about how much faster it is.

Yes, having to compile everything before you can use it is a bit of a pain, but it's worthwhile, IMO: a well-tuned system is just a thrill to use.