Problems met when installing ubuntu with RAID1

0. "BOOTMGR is missing" when installing from usb
A: Format the drive as FAT (not FAT32)


1. Unable to install GRUB in /dev/sdb

A: From the link http://askubuntu.com/questions/43036/how-do-i-install-grub-on-a-raid-system-installation

Many of the answers here are just plain incorrect, telling you to disable BIOS RAID! The correct solution is atthis blog entry. I'll summarize it below.

At the stage of the install where it is attempting to install GRUB it will detect as

/dev/mapper

This is incomplete! That's why the GRUB install fails.

You need the actual name of the RAID array to install to. So during that step, pressctrl+alt+F2 to drop to a busybox terminal, then enter

ls -l /dev/mapper

Pick out the name of your array from the list shown, then press ctrl+alt+F1 to switch back to the install (you can switch back and forth as much as you like with no problems) and enter it in the field as

/dev/mapper/{your array name}

then GRUB installs perfectly and you're ready to go, with a proper BIOS RAID array intact.

It works in my case...

2. What is the default root password of ubuntu?

A: just sudo -i to enter the root mode. 

3. How to enter graphical mode from command line?

A: Plz refer to  http://www.linuxquestions.org/questions/ubuntu-63/%5Bstartx-problem%5D-startx-goes-to-black-grey-screen-and-comes-back-to-command-prompt-853802/

sudo apt-get install xinit

sudo apt-get install ubuntu-desktop  (it takes a long long time...)