grub2 with KDM: reboot on another system

nicofo · #1 6th December 2011, 07:39 PM

Hello,
with Fedora 16 comes grub2 and its integration with KDM: normally, it is possible to chose another system to restart with from KDM, like this:

However for me it doesn't work, although I have informed KDM so (System Settings > Login Screen > Shutdown > Boot manager) and modified /etc/default/grub as indicated http://ksmanis.wordpress.com/2011/04...pport-for-kdm/

Is it working with you ?
Any idea ?

nicofo · #2 9th December 2011, 08:55 PM

Is kdm working with grub2 with you ?

***DBelton*** · #3 9th December 2011, 09:05 PM

I haven't tried using the grub2/KDM feature yet, but did you run grub2-mkconfig after you edited your /etc/default/grub file?

Code:

su -
(root password)

grub2-mkconfig -o /boot/grub2/grub.cfg

nicofo · #4 12th December 2011, 04:33 PM

yes,I did that, but no effect

***DBelton*** · #5 13th December 2011, 04:10 AM

They just had some updates that changed /etc/default/grub that might pertain to your issue here.

In particular, these 2 lines they added to the /etc/grub/default may be what you need:

Code:

GRUB_DEFAULT=saved
GRUB_SAVEDEFAULT=true

You could try adding these 2 lines to your /etc/default/grub file, then run [b]grub2-mkconfig -o /boot/grub2/grub.cfg and see if that helps you out

They also added these lines as well, but wouldn't make any difference in your case:

Code:

GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
# GRUB_TERMINAL="serial console"
# GRUB_SERIAL_COMMAND="serial --unit=0 --speed=9600"

nicofo · #6 16th December 2011, 07:47 PM

Quote:

Originally Posted by DBelton

They just had some updates that changed /etc/default/grub that might pertain to your issue here.

In particular, these 2 lines they added to the /etc/grub/default may be what you need:

Code:

GRUB_DEFAULT=saved
GRUB_SAVEDEFAULT=true

You could try adding these 2 lines to your /etc/default/grub file, then run [b]grub2-mkconfig -o /boot/grub2/grub.cfg and see if that helps you out

They also added these lines as well, but wouldn't make any difference in your case:

Code:

GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
# GRUB_TERMINAL="serial console"
# GRUB_SERIAL_COMMAND="serial --unit=0 --speed=9600"

Hi,
thanks for the suggestion.
I have tested with "GRUB_SAVEDEFAULT=true": it's working... BUT it is not what I want:
With this option, the system you choose in grub becomes the new default entry at the next startup.
It's the only purpose of it (see http://www.gnu.org/software/grub/manual/grub.html for instance).

Any other suggestion ?

marriedto51 · #7 9th January 2012, 10:11 AM

I think I have found the answer to this...

On most systems using grub2, the system commands are just named grub-mkconfig, grub-reboot, etc. On Fedora (presumably to distinguish from legacy grub) they are grub2-mkconfig, grub2-reboot etc.

The login manager expects to run grub-reboot, but we only have grub2-reboot, so a fix (for me at least) is to make a new symbolic link:

Code:

su -c 'ln -s grub2-reboot /sbin/grub-reboot'

Hope that helps.

nicofo · #8 18th January 2012, 08:22 PM

Quote:

Originally Posted by marriedto51

I think I have found the answer to this...

On most systems using grub2, the system commands are just named grub-mkconfig, grub-reboot, etc. On Fedora (presumably to distinguish from legacy grub) they are grub2-mkconfig, grub2-reboot etc.

The login manager expects to run grub-reboot, but we only have grub2-reboot, so a fix (for me at least) is to make a new symbolic link:

Code:

su -c 'ln -s grub2-reboot /sbin/grub-reboot'

Hope that helps.

Hi,
unfortunately it doesn't work for me.
grub[2]-reboot is the only command you've symlinked ?

marriedto51 · #9 19th January 2012, 09:16 AM

I've had another look, and at some stage I think I must also have symlinked /boot/grub/grub.cfg to /boot/grub2/grub.cfg -- perhaps that has an impact?

Code:

su -c 'ln -s ../grub2/grub.cfg /boot/grub/grub.cfg'

nicofo · #10 19th January 2012, 07:47 PM

Quote:

Originally Posted by marriedto51

I've had another look, and at some stage I think I must also have symlinked /boot/grub/grub.cfg to /boot/grub2/grub.cfg -- perhaps that has an impact?

Code:

su -c 'ln -s ../grub2/grub.cfg /boot/grub/grub.cfg'

unfortunately no, still not working... Any other symlink ? ;-)

marriedto51 · #11 20th January 2012, 10:23 AM

Well, I've just tested on a second F16 installation.

All I have created manually is the pair of symlinks

Code:

/sbin/grub-reboot -> grub2-reboot
/boot/grub/grub.cfg -> ../grub2/grub.cfg

My /etc/default/grub contains

Code:

GRUB_DEFAULT=saved
#GRUB_SAVEDEFAULT=true

so that /boot/grub2/grub.cfg contains the line

Code:

set default="${saved_entry}"

near the top, but the menuentry definitions do not contain "savedefault".

The only other thing I can think is that this machine has been rebooted at least once with the default grub config which I believe includes "GRUB_SAVEDEFAULT=true". That will have forced grub to write the saved entry to the grub environment as per the definition of the function savedefault in /boot/grub2/grub.cfg.

Perhaps you could try either: setting the GRUB_SAVEDEFAULT option, remaking /boot/grub2/grub.cfg, and rebooting, then removing GRUB_SAVEDEFAULT and remaking /boot/grub2/grub.cfg; or: manually invoking the grub commands

Code:

saved_entry="menu entry title"
save_env saved_entry

at the grub command prompt.

fduraibi · #12 20th January 2012, 06:01 PM

thanks marriedto51

i just created those two symlinks and it works now, cool.

-- my setup is fresh installed F16 + grub2 + kde 4.7.4 (latest)

nicofo · #13 21st January 2012, 02:14 PM

Thanks, this time it works (finally

)
The problem was, as you mentioned, the option "GRUB_SAVEDEFAULT=true" which was activated in my /etc/default/grub
I have removed it, regenerated grub.cfg => I have the option to reboot instantly.

PS: do you think it's a bug ? I don't see why the option GRUB_SAVEDEFAULT is not compatible with the ability to reboot from KDE ?

fduraibi · #14 23rd January 2012, 04:09 PM

Quote:

Originally Posted by nicofo

Thanks, this time it works (finally

)
The problem was, as you mentioned, the option "GRUB_SAVEDEFAULT=true" which was activated in my /etc/default/grub
I have removed it, regenerated grub.cfg => I have the option to reboot instantly.

PS: do you think it's a bug ? I don't see why the option GRUB_SAVEDEFAULT is not compatible with the ability to reboot from KDE ?

I don't think it is a bug, since i still have the option "GRUB_SAVEDEFAULT=true" in my /etc/default/grub and the reboot menu works. Also i did the same to my home pc and got the reboot menu working. Both systems have that option.

But i think the bug is in the boot menu not recognizing and using grub2 instead of old grub

nicofo · #15 4th February 2012, 07:01 PM

Quote:

Originally Posted by fduraibi

I don't think it is a bug, since i still have the option "GRUB_SAVEDEFAULT=true" in my /etc/default/grub and the reboot menu works. Also i did the same to my home pc and got the reboot menu working. Both systems have that option.

But i think the bug is in the boot menu not recognizing and using grub2 instead of old grub

OK, you're right. The problem was not the option "GRUB_SAVEDEFAULT=true", but the fact that the line

set default="${saved_entry}"

is transformed to

set default=0

in /boot/grub2/grub.cfg although "GRUB_DEFAULT=saved" is in /etc/default/grub.
This happens after a kernel update... (I haven't noticed that in my previous post since I had regenerated /boot/grub2/grub.cfg)

So for me this is a second bug.