Booting into a different entry without changing grub.conf

Booting into a different entry without changing grub.conf

[Mark Ryden]

Hello,

I have in my grub.conf this entry: default=0.
This entry has the original kernel and initrd which came with my Linux
distribution.
Instead of booting to the first entry (default=0) , I want to reboot into the
second entry (which will point to a linux kernel I had build myself
for tests).
; but **withouth** changing the (default=0) entry
in grub.conf to the second grub entry (which contains paths to images which
are selected for boot when default=1); this because in
case I will have a panic when booting (which sometimes occur, for
various reasons)
, I want to be able to reboot the machine immedaitely back to default=0.
(In order that I will NOT have the panic again)
Is it possible ?

Regards,
Mark Ryden

Re: Booting into a different entry without changing grub.conf

[Pavel Roskin]

On Wed, 2008-04-09 at 10:01 +0300, Mark Ryden wrote:
> Hello,
> 
> I have in my grub.conf this entry: default=0.

grub.conf was used in GRUB 1 only, which should be discussed in
bug-grub@gnu.org.  GRUB 2 uses grub.cfg.

> This entry has the original kernel and initrd which came with my Linux
> distribution.
> Instead of booting to the first entry (default=0) , I want to reboot into the
> second entry (which will point to a linux kernel I had build myself
> for tests).
> ; but **withouth** changing the (default=0) entry
> in grub.conf to the second grub entry (which contains paths to images which
> are selected for boot when default=1); this because in
> case I will have a panic when booting (which sometimes occur, for
> various reasons)
> , I want to be able to reboot the machine immedaitely back to default=0.
> (In order that I will NOT have the panic again)
> Is it possible ?

GRUB 1 has "savedefault" for that.  Adding "savedefault 0" to the second
entry would tell grub to boot the first entry next time.  GRUB 2 doesn't
have such facility yet.

-- 
Regards,
Pavel Roskin

Re: Booting into a different entry without changing grub.conf

[Mark Ryden]

Hi,

 I tried it but it did not work. could it be that I was wrong somewhere?
below is the grub.conf.

It was with  default=1, and I changed it to default=2.
I added savedefault=1 to the second error (see below).
I rebooted, got panic, again rebooted, and also in the second
time it rebooted to the 2 , and got again a panic
Any ideas?
following is grub.conf

...

default=2
timeout=5
splashimage=(hd0,1)/boot/grub/splash.xpm.gz
hiddenmenu
title Fedora (2.6.23.1-42.fc8)
	root (hd0,1)
	kernel /boot/vmlinuz-2.6.23.1-42.fc8 ro root=LABEL=/
	initrd /boot/initrd-2.6.23.1-42.fc8.img
title myFedora (2.6.23)
	root (hd0,1)
	kernel /boot/myvmlinz_2_6_23_1 ro root=LABEL=/
	initrd /boot/myinitrd-2.6.23.1.img
	
title netdev (2.6.23)
	root (hd0,1)
	kernel /boot/vmlinuzNetdev ro root=LABEL=/
	initrd /boot/netdev.img
	savedefault=1

Regards,
MR


On Wed, Apr 9, 2008 at 10:19 AM, Pavel Roskin <proski@gnu.org> wrote:
> On Wed, 2008-04-09 at 10:01 +0300, Mark Ryden wrote:
>  > Hello,
>  >
>  > I have in my grub.conf this entry: default=0.
>
>  grub.conf was used in GRUB 1 only, which should be discussed in
>  bug-grub@gnu.org.  GRUB 2 uses grub.cfg.
>
>
>
>  > This entry has the original kernel and initrd which came with my Linux
>  > distribution.
>  > Instead of booting to the first entry (default=0) , I want to reboot into the
>  > second entry (which will point to a linux kernel I had build myself
>  > for tests).
>  > ; but **withouth** changing the (default=0) entry
>  > in grub.conf to the second grub entry (which contains paths to images which
>  > are selected for boot when default=1); this because in
>  > case I will have a panic when booting (which sometimes occur, for
>  > various reasons)
>  > , I want to be able to reboot the machine immedaitely back to default=0.
>  > (In order that I will NOT have the panic again)
>  > Is it possible ?
>
>  GRUB 1 has "savedefault" for that.  Adding "savedefault 0" to the second
>  entry would tell grub to boot the first entry next time.  GRUB 2 doesn't
>  have such facility yet.
>
>  --
>  Regards,
>  Pavel Roskin
>
>
>  _______________________________________________
>  Grub-devel mailing list
>  Grub-devel@gnu.org
>  http://lists.gnu.org/mailman/listinfo/grub-devel
>

Re: Booting into a different entry without changing grub.conf

[Pavel Roskin]

On Wed, 2008-04-09 at 16:07 +0300, Mark Ryden wrote:
> Hi,
> 
>  I tried it but it did not work. could it be that I was wrong somewhere?
> below is the grub.conf.
> 
> It was with  default=1, and I changed it to default=2.
> I added savedefault=1 to the second error (see below).

That should be "savedefault 1", without "=".

> >  GRUB 1 has "savedefault" for that.  Adding "savedefault 0" to the second
> >  entry would tell grub to boot the first entry next time.  GRUB 2 doesn't
> >  have such facility yet.

Please don't top post - it will make it easier for you to see what you
are replying to and notice the difference.  And it will make it easier
for others to quote you.

-- 
Regards,
Pavel Roskin

Re: Booting into a different entry without changing grub.conf

[Mark Ryden]

Hello,
sorry, I checked it; but also with savedefault 1  ( without "=".) it
does not work
Mark

On Wed, Apr 9, 2008 at 10:04 PM, Pavel Roskin <proski@gnu.org> wrote:
> On Wed, 2008-04-09 at 16:07 +0300, Mark Ryden wrote:
>  > Hi,
>  >
>  >  I tried it but it did not work. could it be that I was wrong somewhere?
>  > below is the grub.conf.
>  >
>  > It was with  default=1, and I changed it to default=2.
>  > I added savedefault=1 to the second error (see below).
>
>  That should be "savedefault 1", without "=".
>
>
>  > >  GRUB 1 has "savedefault" for that.  Adding "savedefault 0" to the second
>  > >  entry would tell grub to boot the first entry next time.  GRUB 2 doesn't
>  > >  have such facility yet.
>
>  Please don't top post - it will make it easier for you to see what you
>  are replying to and notice the difference.  And it will make it easier
>  for others to quote you.
>
>  --
>
>
> Regards,
>  Pavel Roskin
>
>
>  _______________________________________________
>  Grub-devel mailing list
>  Grub-devel@gnu.org
>  http://lists.gnu.org/mailman/listinfo/grub-devel
>

Re: Booting into a different entry without changing grub.conf

[Pavel Roskin]

On Wed, 2008-04-09 at 22:10 +0300, Mark Ryden wrote:
> Hello,
> sorry, I checked it; but also with savedefault 1  ( without "=".) it
> does not work

Use default=saved, not default=2.

-- 
Regards,
Pavel Roskin