Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

NOTE: I'm using preseed here , this step should be done automatically from preseed config

This is the final step before finishing installation , install grub to MBR:

enter image description here

I'm not sure which debconf option should use here , to bypass this screen ; after installation , i tried to get all possible used debconf strings , and nothing contains mbr

share|improve this question
You might want to include that you are want to preseed this option more prominently in the question. I missed the tag reading through it the first time and it looks like virpara did the same thing. – adempewolff May 27 '12 at 8:04
up vote 4 down vote accepted

If no other OS detected:

d-i grub-installer/only_debian boolean true

If other OS detected:

d-i grub-installer/with_other_os boolean true

share|improve this answer

It is advised to install GRUB bootloader to MBR (this will replace current bootloader from MBR) after installation. Because MBR tells GRUB to load when the system is booted.

I found this how to make it react for MBR

# This is fairly safe to set, it makes grub install automatically to the MBR
# if no other operating system is detected on the machine.
d-i grub-installer/only_debian boolean true

# This one makes grub-installer install to the MBR if it also finds some other
# OS, which is less safe as it might not be able to boot that other OS.
d-i grub-installer/with_other_os boolean true

and this if you don't want to install in MBR

# Alternatively, if you want to install to a location other than the mbr,
# uncomment and edit these lines:
#d-i grub-installer/only_debian boolean false
#d-i grub-installer/with_other_os boolean false
#d-i grub-installer/bootdev  string (hd0,0)
# To install grub to multiple disks:
#d-i grub-installer/bootdev  string (hd0,0) (hd1,0) (hd2,0)

these configurations are taken from Debian Lenny's preseed file here

this one is helpful for other examples

share|improve this answer
@izx but in first line it says (for lenny) – virpara May 27 '12 at 8:47
sorry, wrong link: this is the preseed example for Debian Squeeze (6.0) – izx May 27 '12 at 8:58

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.