how to restore boot folder?

Question

No laughing!

I just did sudo rm -vr /boot/*. Is there a way to restore the content?

Just to clarify why I would do this: I have a SD-card with a boot-partition mounted at /media/boot that I wanted to replace.

The computer is still running. What are my options?

Update (my solution): This might be a little unsatisfactory for future reference, but I simply backed up all my files and then reinstalled Ubuntu.

Important note if you have the same problem: Don't turn off your computer until you have everything backuped

Solution 1

You can restore /boot from a live CD using a chroot.

http://ubuntuforums.org/showpost.php?p=11893615&postcount=2

Assuming ubuntu is installed in /dev/sda1 ...

sudo mount /dev/sda1 /mnt
sudo cp /etc/resolv.conf /mnt/etc/

Depending on your configuration, you may also need to copy the hosts file

sudo cp /etc/hosts /mnt/etc/

mount /mnt/dev and chroot, configure the chroot

sudo mount --bind /dev/ /mnt/dev
sudo chroot /mnt /bin/bash
mount -t proc none /proc
mount -t sysfs none /sys
mount -t devpts none /dev/pts

To avoid locale issues and in order to import GPG keys

export HOME=/root
export LC_ALL=C

Restore grub

grub-install /dev/sda

If that does not restore the grub files in /boot, reinstall grub first apt-get install --reinstall grub2 grub-install /dev/sda

Reinstall the kernel

apt-get install --reinstall linux-gnereic

Solution 2

Unless you have backups, then the answer is "You can't."

The OS does not keep a backup of that folder for you (or any other to my knowledge) without you expressly telling it to by installing or configuring a backup program.

Your best way forward IMO is to quickly backup any and all files you need to keep from this machine, and reinstall the operating system. I've marked this answer as community wiki so that if I'm wrong, people can update my answer with a note indicating that there's a better way. You may want to wait a day or two if you can in case anyone posts a better answer.

Comments

[Rinzwind]

You are not the 1st: unix.stackexchange.com/questions/13654/… ;)

[Deepak Verma]

He'll also need to put back the OS files. I don't think reinstalling grub will do that, although I didn't read the link. Of course, being Rinzwind, I guess you know the magical incantation to do this. :)

[Firoz Khan]

@Rinzwind: I will try to not reboot, but at some point I will have to.

[Firoz Khan]

Since its still running, I think I will simply back up everything and then reinstall.

[Deepak Verma]

You could try making a CD from Super Grub disk, which fixes a lot of problems automatically. Or, if you prefer to backup and reinstall, you can then copy your backup over the new installation if you feel ambitious.

[Rinzwind]

but 1st make a backup ;) (still smiling)

[Firoz Khan]

This sounds very interesting, but I just backup-ed my files and reinstalled Ubuntu. So I unfortunately I cannot verify if this works.

[vidarlo]

You could probably reinstall the relevant packages tho, to avoid a reinstall. If you rebooted, you could boot a livecd, and chroot into the system and reinstall the packages.

[mark]

Since I have the same issue (wiped the /boot folder and with it the whole EFI partition) I wanted to know if this could also work, when I'm currently running a BIOS Ubuntu and want to chroot into a UEFI Ubuntu (the one with the empty /boot folder).