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+Optional: Creating Backup of Existing GRUB Legacy Installation</t= itle> +<body> + + +Playing with bootloader always brings the danger of leaving your system = in +unbootable state. Fortunately no data is lost in most cases and recovery= is not +hard, but we recommend you to have a bootable CD, DVD or a USB flash dis= k with +Linux around (<uri link=3D"http://www.gentoo.org/main/en/where.xml">Gent= oo +LiveDVD</uri> or <uri link=3D"http://www.sysresccd.org/">System Rescue C= D</uri> +will do) and to backup your current bootloader setup. If your current +bootloader is GRUB legacy, following code sample may help you backing it= up. + + +<pre caption=3D"Backing up GRUB"> +# <comment># copy grub modules and configuration</comment> +# cp -a /boot/grub <keyword>/path/to/backup</keyword>/ +# <comment># backup the MBR and GRUB stage 1.5</comment> +# dd if=3D<keyword>/dev/sda</keyword> of=3D<keyword>/path/to/backup</= keyword>/first-sectors count=3D63 +</pre> + +<note> +Replace <c>/dev/sda</c> with device node of the disk you boot from (this= is +usually and the whole disk like <e>sda</e>, not a partition like sda1) a= nd +<c>/path/to/backup</c> with path to your favourite backup medium. +</note> + + +When something goes wrong, you can restore previous grub installation by +booting some Linux live media and issuing following commands. + + +<pre caption=3D"Restoring GRUB from backup"> +# <comment># move old grub files out of the way</comment> +# mv /boot/grub /boot/grub.nonfunctional +# <comment># copy grub back to /boot</comment> +# cp -a <keyword>/path/to/backup</keyword>/grub /boot/ +# <comment># replace MBR and next 62 sectors of sda with backed up copy = (DANGEROUS!)</comment> +# dd if=3D<keyword>/path/to/backup</keyword>/first-sectors of=3D<keyw= ord>/dev/sda</keyword> count=3D63 +</pre> + +<note> +Replace <c>/dev/sda</c> with device node of the disk you boot from and +<c>/path/to/backup</c> with path to the place where you've stored your b= ackup. +</note> + +<warn> +Writing directly to disk sectors (even those that are outside of partiti= ons +in typical setup) is risky operation and will make your data <e>inaccess= ible</e> +if you changed your parititon layout between backup and restore. Other s= lower +and safer option would be chrooting into your Gentoo installation and +re-installing bootloader - you can use <uri link=3D"/doc/en/handbook/">G= entoo +Handbook</uri> for that task. +</warn> + +</body> +</section> + <section> <title>Setting Useflags