Re: What should I do after clean first 200mb data in /dev/sda by mistake?
I can't guarantee this but it seems you lucked out in not wiping your root partition (/dev/sda5).
First thing I'd do is,
sudo umount /boot
so that your /boot directory is back on / (where it is safe for now). Then comment any /boot mount line in /etc/fstab.
Next, try to fix the MBR. Assuming you're using Grub (the default), and that / is mounted still,
sudo grub-install /dev/sda
That should put the MBR back at start of /dev/sda and install grub related stuff in /boot again. If you get errors here you may have to fix /boot up first.
If you happen to have backups of your /boot directory then I'd restore from that. If not then I guess you'll need to restore the kernel images and whatnot manually. You could try using apt-get install for your current kernel and see if that re-writes the needed stuff. You may need to use --reinstall or some other option to try and force it. If that doesn't go easily you may need to locate and restore the files manually. Once you have /boot set up then I think you can reboot and see if it takes. If not then you'll need to revisit grub-install/update grub to make sure your MBR and /boot are sync'd and working. Don't reboot unless you have the kernel images in /boot as otherwise you'll be stuck fixing this from a LiveCD.
If you succeed with all that then I'd use GParted (system menu) to check sda1 and sda2 and recreate them (set filesystem and format). You'll lose everything on those two partitions but you can re-use them. Once you have sda1 rebuilt you can copy /boot over to there and fix up your mount in fstab again.
Gee. What else? I probably forgot something here.
Last edited by BkkBonanza; August 3rd, 2012 at 12:34 PM.
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