Re: GRUB advice needed.

On Sun, 29 Jan 2006 22:47:59 +0000, Charles Sullivan wrote:

> On Sun, 29 Jan 2006 14:00:39 -0700, Douglas Mayne wrote:
>> On Sun, 29 Jan 2006 20:14:02 +0000, Charles Sullivan wrote:
>>> On Sun, 29 Jan 2006 12:04:07 -0700, Douglas Mayne wrote:
>>>> On Sun, 29 Jan 2006 17:45:07 +0000, Charles Sullivan wrote:
>> Note: comment inline.
>> As I implied, grub is a very flexible loader, and it is rare when the
>> fallback to floppy boot is required. The best course is just to plan in
>> advance what you intend to do, including the boot loader. Grub will
>> usually be able to accomodate your plan. Any time you spend learning
>> about the loader will pay off later.
>> Understanding what you're doing...
>> If you totally wipe out your partition with the "upper" stage files, then
>> you'll need to reinstall before Grub will work again. Note: my question
>> (above) and your answer will dictate how to proceed. Maybe, you should
>> make a grub floppy at this point so you will have a fallback position.
>> Specific advice...
>> One way to proceed is to keep your boot partition intact. When you
>> install new linux distributions, elect to install the grub loader on
>> _its_ root (linux) partition. That way, you can add a simple menu
>> entry on the "master" list on your boot partition's menu.lst. The new
>> entries on the "master" list would look something like this:
>> title Slackware Linux
>> rootnoverify (hd0,5)
>> chainloader +1
>> title OpenSuse Linux
>> rootnoverify (hd0,6)
>> chainloader +1
>> This approach saves copying the kernel and detailed menu.lst entry
>> necessary to load a specific distribution's kernel. You will have a
>> layered menu (menu upon menu), but in my opinion that is the simpler
>> choice.
>> Just keep your plan straight in your mind (or on paper). You are
>> more likely to have success that way.
> By "new" I meant new-from-the-store. I should probably explain
> that when my current "main" HDD gets a little age on it, I buy a
> new (and usually larger) one. I physically install it as /dev/hda
> and load Linux on it from scratch. I physically relocate the
> old one to /dev/hdb or hdc and copy over whatever files I need
> onto the new /dev/hda. Eventually the old one is removed and
> stored - if I ever need it I can just plug it in again as /dev/hda
> and boot it up.

Ok, then one of the first steps with the new disc would be to build a boot
partition (with dual booting in mind.) Setup the grub loader, per the
usual drill.

> OK, I think I'm now getting the picture: I keep a boot partition but the
> only things on it are the grub files - the kernel and such goes into the
> /boot directory on the root partition for that particular Linux version
> and a grub stage 2 loader goes in the PBR of the same root partition. Is
> that correct?
Note: comment inline.

You've got it, almost. I reread my last post and wished I could have been
clearer. The confusion comes because you will be dual booting. What I
am advocating is _independant_ boot methods, controlled by one "master"
grub. Any other linux distributions which may be installed will be setup
with their own boot loaders on their own root (linux) partitions. Because
the loaders are independant, the grub stanza's using "chainloader" is
appropriate (and the grub stage files don't really enter into the big
picture at this level of abstraction.)

For example, say you are installing Slackware as a test linux
distribution. (That is a terrific idea, BTW ;-)). Slackware uses
lilo by default for its bootloader. "Setup" offers to install lilo
as one of the final setup steps. You would choose to install lilo at
on the root (linux) partition. Then, you would manually add a "Slackware"
stanza to your grub menu (as I showed earlier). The two loaders are
independant, connected by chainloader. You can fix the loader for
slackware to use grub after Slackware is booted the first time.

You could then install another linux distribution, using the same idea.
You could then install another linux distribution, using the same idea.

It's harder to describe, than it is to do. As I said, layout your plan on
paper, and you'll be on your way. Here is a table for getting started.

Partition Used for Size or % Comments
--------- ----------- ---------- ---------
MBR boot loader 512 bytes Use grub
1 grub (master) 10-100M no need to be too stingy
2 common swap ? if only one distro at a time
3 extended ? remainder of disc
5 Slackware ? rocks!
6 OpenSuse ?
7 Ubuntu ?

Douglas Mayne