[SOLVED] lost boot partition: how to reinstall?

[magfan]

I just lost my boot partition and I was unable to repair it. How can I reinstall everything which belongs in in /boot from within the Mageia-rescue system? I know I need grub and at least one kernel image but I do not know how to install them...

[gohlip]

This might help.
http://www.gnu.org/software/grub/manual ... B-natively

Good luck.

[magfan]

OK, installing grub works. But still I miss the kernel images to boot. How can I force to reinstall them?

[gohlip]

Right, I am not too clear about grub is now installed but kernel image not there to boot.
If you can boot into Mageia, but new kernel is not there, just go to Mageia Control center and install new kernel and don't forget to go to "boot --> set up boot" after that.

If you mean grub is there (only grub prompt "grub>"), with no menu at all, try typing this and press enter after each line.
grub> kernel (hd0,x)/boot/vmlinuz BOOT_IMAGE=linux root=/dev/sdax nokmsboot ro vga=788
grub> initrd (hd0,x)/boot/initrd.img
grub> boot

where (hd0,x) and /dev/sdax is Mageia partition - (careful that (hd0,x) is /dev/sda(x+1)) ie, if Mageia is in sda3,, you use (hd0,2) and /dev/sda3 in the kernel line.

And if somehow it doesn't boot - most likely due to initramfs failure when installing kernel, type in this
grub> kernel (hd0,x)/boot/vmlinuz-3.3.6-desktop-2.mga2 BOOT_IMAGE=linux root=/dev/sdax nokmsboot ro vga=788
grub> initrd (hd0,x)/boot/initrd-3.3.6-desktop-2.mga2.img
grub> boot


Again, don't forget to make sure kernel is reinstalled at Mageia Control Center and go to "boot --> set up boot" after that.

[doktor5000]

Right, I am not too clear about grub is now installed but kernel image not there to boot.
If you can boot into Mageia, but new kernel is not there, just go to Mageia Control center and install new kernel and don't forget to go to "boot --> set up boot" after that.

If i understood correctly, /boot was wiped, in that case there's no kernel to boot and mcc is not available.

@magfan: You need to know which kernel packages were installed, e.g.

Code: Select all

rpm -qa | grep kernel

and then just reinstall them via

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urpmi --replacepkgs kernel_packages_to_install

Should even be possible to do just that directly via substitution:

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urpmi --replacepkgs $(rpm -qa | grep kernel)

[gohlip]

If i understood correctly, /boot was wiped, in that case there's no kernel to boot and mcc is not available.

@doktor5000, Good to point out this might be the case. But if so, wouldn't he has to chroot from a livecd to get back any kernel?
@magfan, sorry for this digression.

[magfan]

Right, I am not too clear about grub is now installed but kernel image not there to boot.
If you can boot into Mageia, but new kernel is not there, just go to Mageia Control center and install new kernel and don't forget to go to "boot --> set up boot" after that.

If i understood correctly, /boot was wiped, in that case there's no kernel to boot and mcc is not available.

@magfan: You need to know which kernel packages were installed, e.g.

Code: Select all

rpm -qa | grep kernel

and then just reinstall them via

Code: Select all

urpmi --replacepkgs kernel_packages_to_install

Should even be possible to do just that directly via substitution:

Code: Select all

urpmi --replacepkgs $(rpm -qa | grep kernel)

Yes, /boot was completely wiped. From where do I have to call

Code: Select all

urpmi --replacepkgs

? If I use Mageia-Rescue-System and do a chroot the required kernel packages are not found.

And there is still something strange with the kernel packages. According to

Code: Select all

rpm -qa

I have only

Code: Select all

kernel-*-server-*

installed. But when I call

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dracut -f -d st

it creates an

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initrd-*-desktop-*

. Can I simply rename it? The module st (for tapes) is not loaded automatically. So I will have to use dracut.

[doktor5000]

Yes, /boot was completely wiped. From where do I have to call

Code: Select all

urpmi --replacepkgs

? If I use Mageia-Rescue-System and do a chroot the required kernel packages are not found.

Yes, inside the chroot of your broken installation. And you need to setup networking there to install other packages ...
(At first i thought the broken installation was still running, and you want to switch to rescue mode by rebooting, so maybe i misunderstood a bit there)

And what do you mean, the required kernel packages are not found - you mean urpmi doesn't find them? Sure, because the chroot doesn't have repositories set up.
Let's just clear up the first part, then we can look at your dracut issue.

[Ken-Bergen]

And there is still something strange with the kernel packages. According to

Code: Select all

rpm -qa

I have only

Code: Select all

kernel-*-server-*

installed. But when I call

Code: Select all

dracut -f -d st

it creates an

Code: Select all

initrd-*-desktop-*

. Can I simply rename it? The module st (for tapes) is not loaded automatically. So I will have to use dracut.

Thoughts.
Even though rpm reports kernel-server-XXX as installed it's not really there after wiping /boot.

Code: Select all

dracut

as you used it would build and install the currently running kernel.

Can you now boot into the system with the new initrd?

[magfan]

Well there were several additional problems:

1. a certain driver (r8169) was not loaded in rescue mode and I was unable to load it manually
2. mcc in console mode does not let me specify a proxy; so even with a working network card setting up an online repository would fail

Finally I came up with a "brute force" solution:

1. resizing existing partitions with gparted on Knoppix to gain space for a new partition
2. installing Mageia 2 from DVD with the wiped /boot partition mounted as /boot, the rest in "/".
3. reboot once to see whether everything works (it did!)
4. reboot into Mageia-rescue-system to edit menu.lst to use the old root partition ("/") and reinstall boot loader
5. booting into my old Mageia installation

One good thing is that now I have a spare partition which I may use later for a fresh install of Mageia 3 in case the online upgrade fails. Some people may remember that I had several issues with upgrading from mga1 to mga2...