[gentoo-user] grub2 defaults

[gentoo-user] grub2 defaults

[James]

Howdy,

So I have these entries in my /etc/default/grub file:

GRUB_DISTRIBUTOR="Gentoo"
GRUB_DEFAULT=kernel-3.13.6-gentoo
GRUB_HIDDEN_TIMEOUT=3
GRUB_TIMEOUT=10
GRUB_GFXMODE=1024x768

I ran 'grub2-mkconfig -o /boot/grub/grub.cfg'
after the last ebuild of 3.13.6-gentoo


/boot shows:
kernel-3.13.0-gentoo
kernel-3.13.0-gentoo-r1
kernel-3.13.1-gentoo
kernel-3.13.6-gentoo
kernel-3.13.6B-gentoo
kernel-3.13.7-gentoo


Obviously, I like to kept kernel experiments around a while....

So when I get the Grub2 (ascii) boot menu and just select the 
default, it boots kernel-3.13.7-gentoo, despite 
'kernel-3.13.6-gentoo' being set in as the default for Grub2?

Comment thoughts and suggestions, including deeper reading on grub2
is most welcome, particulary Grub2 examples.

Also, is there a nice 'gui' boot-menu for grub2 ?

It seems to take several repeated attemps for grub2 to correctly
use the kernel I desire, despite what syntax/order I use.
If I boot a kernel that is not the default, it takes about 2 minutes,
then another 2 minutes of blank screen then it boot fairly quickly.
The mobo is a GA-99FXA-UD3 and this might not have the bios/uefi/???
optimally configured? (first gigabyte moble).

The is what I have read on grub2 (man pages, gentoo wiki) so additional
reading, with some useful examples would also be much appreciated.

Re: [gentoo-user] grub2 defaults

[Neil Bothwick]

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On Tue, 25 Mar 2014 20:42:07 +0000 (UTC), James wrote:

> So I have these entries in my /etc/default/grub file:
> 
> GRUB_DISTRIBUTOR="Gentoo"
> GRUB_DEFAULT=kernel-3.13.6-gentoo
> GRUB_HIDDEN_TIMEOUT=3
> GRUB_TIMEOUT=10
> GRUB_GFXMODE=1024x768
> 
> I ran 'grub2-mkconfig -o /boot/grub/grub.cfg'
> after the last ebuild of 3.13.6-gentoo
> 
> 
> /boot shows:
> kernel-3.13.0-gentoo
> kernel-3.13.0-gentoo-r1
> kernel-3.13.1-gentoo
> kernel-3.13.6-gentoo
> kernel-3.13.6B-gentoo
> kernel-3.13.7-gentoo
> 
> 
> Obviously, I like to kept kernel experiments around a while....
> 
> So when I get the Grub2 (ascii) boot menu and just select the 
> default, it boots kernel-3.13.7-gentoo, despite 
> 'kernel-3.13.6-gentoo' being set in as the default for Grub2?

DEFAULT, if not set to a number, matches the title or --id of a menu
entry, not the kernel name (you could have several entries with the same
kernel).

> Also, is there a nice 'gui' boot-menu for grub2 ?

Yes, GRUB2 can use themes. The starfield theme is included, uncomment the
GRUB_THEME setting in the defaults file.

> The is what I have read on grub2 (man pages, gentoo wiki) so additional
> reading, with some useful examples would also be much appreciated.

The grub info pages are more helpful than the man page.


-- 
Neil Bothwick

Always be sincere even if you don't mean it.

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[gentoo-user] Re: grub2 defaults

[James]

Neil Bothwick <neil <at> digimed.co.uk> writes:


> > GRUB_DISTRIBUTOR="Gentoo"
> > GRUB_DEFAULT=kernel-3.13.6-gentoo
> > GRUB_HIDDEN_TIMEOUT=3
> > GRUB_TIMEOUT=10
> > GRUB_GFXMODE=1024x768

> > /boot shows:
> > kernel-3.13.0-gentoo
> > kernel-3.13.0-gentoo-r1
> > kernel-3.13.1-gentoo
> > kernel-3.13.6-gentoo
> > kernel-3.13.6B-gentoo
> > kernel-3.13.7-gentoo

> > So when I get the Grub2 (ascii) boot menu and just select the 
> > default, it boots kernel-3.13.7-gentoo, despite 
> > 'kernel-3.13.6-gentoo' being set in as the default for Grub2?

> DEFAULT, if not set to a number, matches the title or --id of a menu
> entry, not the kernel name (you could have several entries with the same
> kernel).
Do you have syntax examples for --id, or is that just a generic descriptor?

So would the option for local kernel versioning built into the 
kernel be recognized by grub2 to distinguishing between differnent
(locale) versions of the same kernel version?

menuconfig-->  General Setup-->  Local version-append to kernel release 
???

OR:
So how do I know which number matches which kernel, since using the
name does not match them up as desired to select to boot?

> Yes, GRUB2 can use themes. The starfield theme is included, uncomment the
> GRUB_THEME setting in the defaults file.

ok. I'll give this whirl and see what I come up with that works
for my kernel experiments....

thx,
James

Re: [gentoo-user] Re: grub2 defaults

[Neil Bothwick]

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On Wed, 26 Mar 2014 14:42:51 +0000 (UTC), James wrote:

> > > So when I get the Grub2 (ascii) boot menu and just select the 
> > > default, it boots kernel-3.13.7-gentoo, despite 
> > > 'kernel-3.13.6-gentoo' being set in as the default for Grub2?  
> 
> > DEFAULT, if not set to a number, matches the title or --id of a menu
> > entry, not the kernel name (you could have several entries with the
> > same kernel).  
> Do you have syntax examples for --id, or is that just a generic
> descriptor?

--id "some string" - it's in the info pages.

> So would the option for local kernel versioning built into the 
> kernel be recognized by grub2 to distinguishing between differnent
> (locale) versions of the same kernel version?
> 
> menuconfig-->  General Setup-->  Local version-append to kernel release 
> ???

You want the name of the menuentry, not the name of the kernel. I use a
custom script to generate the entries, but running the standard 10linux
script here produces entries like

menuentry 'GNU/Linux, with Linux 3.13.7-gentoo'

You would need to match on that for DEFAULT.

> OR:
> So how do I know which number matches which kernel, since using the
> name does not match them up as desired to select to boot?

By looking at grub.cfg. Unfortunately, this changes each time you add a
kernel, the number for that older one increments each time.

If you have a particular entry you want to boot, you may be better off
defining a menu entry for it in /etc/grub.d/40_custom, then you can set
the name for it and your DEFAULT setting should work.


-- 
Neil Bothwick

Micro-: (prefix) anything both very small and very expensive.

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Re: [gentoo-user] grub2 defaults

[thegeezer]

On , James wrote:
> Howdy,
> 
> So I have these entries in my /etc/default/grub file:
> 
> GRUB_DISTRIBUTOR="Gentoo"
> GRUB_DEFAULT=kernel-3.13.6-gentoo

I don't think this will work -- it is the title of menu entry you need 
not the kernel executable

> GRUB_HIDDEN_TIMEOUT=3
> GRUB_TIMEOUT=10
> GRUB_GFXMODE=1024x768
> 
> I ran 'grub2-mkconfig -o /boot/grub/grub.cfg'
> after the last ebuild of 3.13.6-gentoo
> 
> 
> /boot shows:
> kernel-3.13.0-gentoo
> kernel-3.13.0-gentoo-r1
> kernel-3.13.1-gentoo
> kernel-3.13.6-gentoo
> kernel-3.13.6B-gentoo
> kernel-3.13.7-gentoo
> 
> 
> Obviously, I like to kept kernel experiments around a while....
> 
> So when I get the Grub2 (ascii) boot menu and just select the
> default, it boots kernel-3.13.7-gentoo, despite
> 'kernel-3.13.6-gentoo' being set in as the default for Grub2?
> 

Grub2 seems to do things a little differently.
I've been working through my list especially for headless and failed 
boots.
you want in /etc/default/grub
GRUB_DEFAULT=saved
GRUB_SAVEDEFAULT=true

just an aside if you are going headless you want GRUB_SAVEDEFAULT=false 
especially for a fallback boot option. if you don't want the selection 
just booted to become the default, you set this to false.

once you have that you can then
# grub2-set-default 'Gentoo GNU/Linux, with Linux x86_64-3.13.6-gentoo'

it would be nice if there was a way of getting id menu numbers.
i've not looked into the grub2-mkconfig but i get a menu with a single 
default option and advanced options wiht previous kernels listed in 
there.
id numbers would not work too well with sub menus, but i recently had a 
message from grub saying that because my default option had been moved 
to the advanced option it should be amended to be
# grub2-set-default 
'gnulinux-x86_64-3.12.13-gentoo-advanced-a48a107b-c379-4c72-bcda-25011968eab5'


also for booting an option once, on the next reboot you can use
# grub2-reboot 'GNU/Linux, with Linux x86_64-6.13.6-gentoo'

afaik if your kernel/initramfs use custom names e.g. PeterRabbit-vmlinuz 
with PoohBear-initramfs   grub2-mkconfig doesn't work for you, so make 
sure your files conform.


> Comment thoughts and suggestions, including deeper reading on grub2
> is most welcome, particulary Grub2 examples.
> 
> Also, is there a nice 'gui' boot-menu for grub2 ?
> 
> It seems to take several repeated attemps for grub2 to correctly
> use the kernel I desire, despite what syntax/order I use.
> If I boot a kernel that is not the default, it takes about 2 minutes,
> then another 2 minutes of blank screen then it boot fairly quickly.
> The mobo is a GA-99FXA-UD3 and this might not have the bios/uefi/???
> optimally configured? (first gigabyte moble).
> 
> The is what I have read on grub2 (man pages, gentoo wiki) so additional
> reading, with some useful examples would also be much appreciated.

[gentoo-user] Re: grub2 defaults

[James]

 <thegeezer <at> thegeezer.net> writes:


> > So I have these entries in my /etc/default/grub file:

> I don't think this will work -- it is the title of menu entry you need 
> not the kernel executable


Ok, Neil; geezer, I've gotta do some scratching, experimenting
and pondering how/what I want to do. I'll post back, but, if it
is more than a few days (most likely) I'll just post a new thread
with some background.... and my latest ideas....

thx.........
James