how to restore boot loader ?

paradise · 05-28-2013, 07:07 AM

Hello,

I have installed FreeBSD 9.1, which was working fine, but I made a mistake and I cannot boot anymore, I get "Missing boot loader" when, like usual, I want to boot directly on FreeBSD DD.

Here is my configuration :

- sda : Fedora 17
- sdb : XP/Slacware14.0
- sdc : FreeBSD 9.1

MBR is on sda, I use Grub2 to launch all my OS (excepted FreeBSD)..

I wanted to configurate files in Fedora to boot FreeBSD from Fedora Grub, and I unfortunately put a flag on sdc1 from Gparted, and I cannot boot anymore when I start directly on the FreeBSD DD.

So, is this command right to re-install the boot loader, being in "Single user" with the ISO DVD :

Code:

fdisk -B -b /boot/boot0 /dev/ad3

or this one :

Code:

fdisk -B -b /boot/boot0 ada3

And '3' is tne right number ?

I should like to avoid to increase my Grub, or have to re-install the all FreeBSD.

Thank you for your answer, and sorry for my english, I am French...

rtmistler · 05-28-2013, 07:47 AM

You should be able to re-install just grub or grub2 and get it working. Perform a web search for "freebsd reinstall grub" and evaluate which problem/solution options look best to you. Don't embark on something you question, or don't understand well enough to grasp the idea of what it's intention is.

I just have no real experience with that distro. But to me, grub2 is newer, you can boot off of a CD or thumbstick, and install grub2 on the hard drive. What I'd do is see about the configuration files you have which can identify the distribution, however grub is also capable of scanning and locating distributions for you so that it will create it's own config.

paradise · 05-28-2013, 10:45 AM

Thank you for your answer.

I have no problem with Fedora Grub, it is not able to boot FreeBSD right now, but it does not matter, I can read ufs partition at least and boot the other OSs, Grub2 automatically recognizes them (Win, Linux), but not BSD OS (and nor Solaris, AIX, I think).

For booting FreeBSD, I change the boot drive in the BIOS, but now I can't any more boot it at all without the boot loader.

Yes, one solution can be in installing Grub2 in FreeBSD, but the command to do it is not easier than re-installing the simple Boot Loader, that's why I asked how to do it.

Otherwise, I shall re-install FreeBSD...

rtmistler · 05-28-2013, 12:11 PM

I'm suspecting, as you likely already do too, that the partition change you've made has caused this problem.

If you can undo that flag and set that partition back the way it was originally, then maybe you can get it to boot as you had been doing previously.

teckk · 05-28-2013, 01:34 PM

http://forums.freebsd.org/showthread.php?t=33003
http://www.freebsd.org/doc/en/books/faq/disks.html
http://www.freebsd.org/doc/en/books/...ml#idp75706672

paradise · 05-28-2013, 07:31 PM

Thank you for your answers.

I have spent a lot of time on looking how to fix it.

I succeeded in re-installing the boot loader, but not really, I used this command in Single User with the ISO DVD :

Code:

fdisk -B -b /boot/boot0 ada2

After the reboot I get this :

Code:

F1 ?
F5 Drive 1

F6 PXE
Boot: F5

The key F1 makes #, and the key F5 gives :

Code:

GRUB Loading stage1.5

GRUB Loading, please wait...
Error 15

which is normal, it cannot boot Grub.

After that I can only press Ctrl+Alt+Del keys to reboot the system.

Something is missing, for sure, cause of the ? after F... Maybe a label for the boot partition ?

I think that I have to write something like :

Code:

bsdlabel -B ada2s1

in Single User, but I am not sure...?

I am tired, I think that the best solution is to re-install FreeBSD...

paradise · 05-29-2013, 09:03 AM

So, I di dnot find any issue, so I re-installed FreeBSD.

I am still looking for the good syntax in Grub2 of Fedora to boot from it (menuentry), if it is possible, maybe there is a bug in Fedora17..

See you all !