Re: [gentoo-user] [OT] How to do GRUB2 multiple partions on USB key?

[Tom H]

On Sun, Jan 22, 2017 at 10:39 PM, Walter Dnes  wrote:
>
> I notice some comments that menu.lst is "legacy GRUB", and GRUB2 has
> gone off the deep end with a ton of config files.

Unless you want to customize your grub menu in a way not desired or
anticipated by the grub2 developers, you just have to edit
"/etc/default/grub" and run "grub-mkconfig -o /boot/grub/grub.cfg".

Re: [gentoo-user] [OT] How to do GRUB2 multiple partions on USB key?

[Tom H]

On Sun, Jan 22, 2017 at 6:02 AM, Neil Bothwick  wrote:
>
> GRUB2 counts partitions from 1, but drives from 0 (a brilliant
> decision) so these would be (hd1,6) and (hd1,7).

They should've changed hd0/hd1/... to hda/hdb/... when they changed
(hd0,msdos1) to correspond to /dev/sda1 [as opposed to (hd0,0) in
grub1!], (hd1,gpt2) to correspond to /dev/sdb2, ... :(

Re: [gentoo-user] [OT] How to do GRUB2 multiple partions on USB key?

[Neil Bothwick]

On Sun, 22 Jan 2017 22:39:09 -0500, Walter Dnes wrote:

> > Why are you using GRUB now, does LILO not work on USB sticks?  
> 
>   Apparently, further development on LILO has ceased according to...
> http://www.phoronix.com/scan.php?page=news_item=LILO-Bootloader-EOY
> I don't need it NOW, but I do want to be ready for when I do run into a
> situation that LILO can't handle.  If I'm going to be playing around and
> learning and possibly screwing up, I'd rather do it to a USB key install
> than to a hard drive install.

Fair point.

>   I notice some comments that menu.lst is "legacy GRUB", and GRUB2 has
> gone off the deep end with a ton of config files.

GRUB2 has one config file, but it's now called grub.cfg. However, GRUB2
can also generate its own config, and that uses a ton of other config
files, for values of ton <3. All you need to edit is /etc/default grub
and maybe the custom menu file in /etc/grub.d.

> Is syslinux/extlinux
> still supported?  I wonder if that might be simpler while still useful.

Yes and no. It works but it is nowhere near as clearly documented as
GRUB. It may take you a little while to get the hang of GRUB, but that's
what you are planning for, so fine. But it will all make sense soon
enough and it is the most versatile bootloader out there.


-- 
Neil Bothwick

Despite the cost of living, have you noticed how it remains so popular?


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Re: [gentoo-user] [OT] How to do GRUB2 multiple partions on USB key?

[Walter Dnes]

On Sun, Jan 22, 2017 at 11:02:21AM +, Neil Bothwick wrote
> On Sun, 22 Jan 2017 08:59:43 +, Mick wrote:
> 
> > The nomenclature for partions 6 and 7 on the USB key will be (hd1,5)
> > and (hd1,6) respectively, as long as the USB key has been detected as
> > the 2nd drive on the PC (/dev/sdb).
> 
> GRUB2 counts partitions from 1, but drives from 0 (a brilliant decision)
> so these would be (hd1,6) and (hd1,7).
> 
> Why are you using GRUB now, does LILO not work on USB sticks?

  Apparently, further development on LILO has ceased according to...
http://www.phoronix.com/scan.php?page=news_item=LILO-Bootloader-EOY
I don't need it NOW, but I do want to be ready for when I do run into a
situation that LILO can't handle.  If I'm going to be playing around and
learning and possibly screwing up, I'd rather do it to a USB key install
than to a hard drive install.

  I notice some comments that menu.lst is "legacy GRUB", and GRUB2 has
gone off the deep end with a ton of config files.  Is syslinux/extlinux
still supported?  I wonder if that might be simpler while still useful.

-- 
Walter Dnes 
I don't run "desktop environments"; I run useful applications

Re: [gentoo-user] [OT] How to do GRUB2 multiple partions on USB key?

[Mick]

On Sunday 22 Jan 2017 11:02:21 Neil Bothwick wrote:
> On Sun, 22 Jan 2017 08:59:43 +, Mick wrote:
> > The nomenclature for partions 6 and 7 on the USB key will be (hd1,5)
> > and (hd1,6) respectively, as long as the USB key has been detected as
> > the 2nd drive on the PC (/dev/sdb).
> 
> GRUB2 counts partitions from 1, but drives from 0 (a brilliant decision)
> so these would be (hd1,6) and (hd1,7).

Oops!  Yes, sorry Walter, I missed that in my previous message!

-- 
Regards,
Mick

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Re: [gentoo-user] [OT] How to do GRUB2 multiple partions on USB key?

[Neil Bothwick]

On Sun, 22 Jan 2017 08:59:43 +, Mick wrote:

> The nomenclature for partions 6 and 7 on the USB key will be (hd1,5)
> and (hd1,6) respectively, as long as the USB key has been detected as
> the 2nd drive on the PC (/dev/sdb).

GRUB2 counts partitions from 1, but drives from 0 (a brilliant decision)
so these would be (hd1,6) and (hd1,7).

Why are you using GRUB now, does LILO not work on USB sticks?


-- 
Neil Bothwick

Znqr lbh ybbx!


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Re: [gentoo-user] [OT] How to do GRUB2 multiple partions on USB key?

[Mick]

On Saturday 21 Jan 2017 00:44:15 Walter Dnes wrote:
>   I've been using LILO for over 15 years, but I'm a total newbie at
> GRUB2, so the following may be totally out to lunch.  Would the following
> setup work for a USB key with multiple partitions with a different OS or
> variant in each partition?
> 
> GRUB2 in MBR

It can be the MBR of the USB key, or the MBR of the hard drive.  It makes 
sense it is in the MBR of the USB key of course, but bear in mind some older 
PCs BIOS will not boot from USB keys.

> * extended partition 1 covers entire USB key
> * logical partition 5, ext2fs, 1 megabyte, containing directory /boot/grub
>   containing file menu.lst
> * logical partition 6, ext2fs, containing an OS
> * logical partition 7, ext2fs, containing an OS
> * etc, etc

Or, you could just use GPT. 


>   Assuming that the key shows up as /dev/sdb, would the entries in
> menu.lst for partions 6 and 7 be (hd1,5) and (hd1,6), respectively?

I think you are confusing GRUB2 with the older GRUB legacy?  There is no 
menu.lst with GRUB2.  Instead /boot/grub/grub.cfg is generated when you run:

 grub-mkconfig -o /boot/grub/grub.cfg

taking its input from:

 /etc/default/grub

and 

 /etc/grub.d/*

The nomenclature for partions 6 and 7 on the USB key will be (hd1,5) and 
(hd1,6) respectively, as long as the USB key has been detected as the 2nd 
drive on the PC (/dev/sdb).


> And
> what would be the command to install GRUB2 to the MBR of the USB key?

grub-install -v /dev/sdb

and then to create and install its configuration files mount your USB key and 
run:

grub-mkconfig -o /run/media/walter//boot/grub/grub.cfg

assuming that your USB key has been mounted under /run/media/walter/

and the directory /boot on the USB key is where you want your GRUB2 files 
installed.

Should you need to have a look here as well for additional info:

https://wiki.gentoo.org/wiki/GRUB2
https://www.gnu.org/software/grub/manual/grub.html

HTH.
-- 
Regards,
Mick

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[gentoo-user] [OT] How to do GRUB2 multiple partions on USB key?

[Walter Dnes]

  I've been using LILO for over 15 years, but I'm a total newbie at
GRUB2, so the following may be totally out to lunch.  Would the following
setup work for a USB key with multiple partitions with a different OS or
variant in each partition?

GRUB2 in MBR
* extended partition 1 covers entire USB key
* logical partition 5, ext2fs, 1 megabyte, containing directory /boot/grub
  containing file menu.lst
* logical partition 6, ext2fs, containing an OS
* logical partition 7, ext2fs, containing an OS
* etc, etc

  Assuming that the key shows up as /dev/sdb, would the entries in
menu.lst for partions 6 and 7 be (hd1,5) and (hd1,6), respectively?  And
what would be the command to install GRUB2 to the MBR of the USB key?

-- 
Walter Dnes 
I don't run "desktop environments"; I run useful applications