How to chroot in linux.

First Mounting /proc and /dev

# mount -t proc none /mnt/gentoo/proc
# mount -o bind /dev /mnt/gentoo/dev

Chrooting into the new environment

# chroot /mnt/gentoo /bin/bash

Enjoy.

How to install grub in raid 1 patitions on Linux.

Now will show you how to install grub in raid 1 partions, for booting from each hard disk.

First we run next command:
[root@~]# grub-install

Waiting for finish first commnad, now next step:
[root@~]# grub
grub>device (hd0) /dev/sda
grub>root (hd0,0)
grub>setup (hd0)
grub>device (hd1) /dev/sdb
grub>root (hd1,0)
grub>setup (hd1)
grub>quit
[root@~]#

Now have to create conf file for grub.

[root@~]# cp /boot/grub/menu.lst.example /boot/grub/menu.lst

Now edit file:

[root@~]# vi /boot/grub/menu.lst

timeout 10
color 4
#splashimage (hd0,4)/grub/mdv-grub_splash.xpm.gz
default 0
#viewport 3 2 77 22
#shade 1
fallback 1

title linux1
kernel (hd0,0)/vmlinuz-2.6.31.5-desktop-1mnb root=/dev/md2 vga=792 resume=/dev/md1
initrd (hd0,0)/initrd-2.6.31.5-desktop-1mnb.img

title linux2
kernel (hd1,0)/vmlinuz-2.6.31.5-desktop-1mnb root=/dev/md2 vga=792 resume=/dev/md1
initrd (hd1,0)/initrd-2.6.31.5-desktop-1mnb.img

Now you have to be sure about your kernel, vmlinuz and initrd. You can find this informations in /boot

Now save file, and you can reboot you Linux sistem, and see the grub bootloader.

Enjoy.