Install Ubuntu on efi machine with windows 8 preinstalled (possibly remove windows 8)

Question

I read Alvarado's tutorial on how to install Ubuntu on an EFI machine with preinstalled windows 8 from Installing Ubuntu Alongside a Pre-Installed Windows with UEFI.

That's a nice and detailed explanation. I am about to use it. However I would like to ask some questions. Before doing this, let me describe my situation and my aims.

I have an Asus laptop N76V with an EFI bios and a preinstalled windows 8. I could disable fast boot (in the bios and within windows 8) and secure boot. It seems that I cannot disable EFI but I could launch a CSM option. Windows still starts up correctly. I have two SATA drives with size 750GB each. From the partition manager in windows 8, I see the following:

Drive 0: EFI system partition, 300 MB
         recover partition, 600 MB
     primary partition with OS (C:), NTFS, 372,6 GB (contains windows 8)
     primary partition (D:), NTFS, 537,89 GB (for data)
     recover partition, 20,01 GB

Drive 1: primary partition (E:), NTFS, 465,75 GB (for data) 
     primary partition (F:), NTFS, 465,76 GB (for data)

First aim: install Ubuntu 12.04.2 (and maybe another linux system) on the drive 1 and conserve windows 8.

Second aim: install Ubuntu 12.04.2 (and maybe another linux system) on the drive 1, remove windows 8 and install another linux system on the drive 0.

For the first aim, I could follow your advices. However I want to be sure I understood correctly. When he wrote, one should partition within windows 8, it means that one should create for instance an ext3 partition for /, a swap partition, and an ext3 partition for /home using the partition manager in windows? Then, when installing Ubuntu, choose manual partitioning, just attribute the mount point to each relevant partitions and do not format them. Is that correct?

Where should I put the boot loader (grub) for Ubuntu? At the beginning of the partition /?

In fact, I do not really want conserve Windows 8. I would prefer to erase it at the right time and to be able to partition the drives and to install several Linux systems (this is aim 2). Has anyone have hints or a reference to a tutorial for this?

Answer 1

Do not create partitions with Windows partition tools. Use Windows only to shrink NTFS partitions to make room for Linux formatted partitions. Windows may convert even with gpt partitioned drives to dynamic partitioning which does not work with Linux. With gpt dynamic may also be called LDM.

Are both drives partitioned with gpt not MBR? UEFI needs gpt partitioning to boot although Linux will boot from gpt partitioned drives in BIOS mode. Windows only boots from gpt partitioned drives with UEFI.

While system will boot only from one efi partition, with two drives it is worthwhile to manually partition and include an efi partition on every drive. Grub is installed to the efi partition of the drive you boot from. But with multiple drives, one drive can eventually fail and if you have boot loader also in other drive (and current) you can change UEFI/BIOS to boot second working drive.

With UEFI, grub2's bootloader is installed to the efi partition. Only with BIOS installs do you install grub2's boot loader to the MBR of the drive or sda (or sdb). Each system you install should create a folder in the efi partition with it boot loader. With Ubuntu and multiple installs you may only have the most current install in the ubuntu folder and use the grub menu to choose other installs.

Answer 2

I can now explain to you what I did on my computer Asus laptop N76V. This answers (at least partially) my questions.

Keeping permanently in mind Luis Alvarado's tutorial

• Installing on a Pre-Installed Windows 8 System (UEFI Supported),

I actually followed another one, namely

• http://forum.ubuntu-fr.org/viewtopic.php?id=757311

Since it is written in French, I shall sketch the main steps I did.

The main difference compared to the procedure proposed by Luis Alvarado consists in creating a new efi partition. Since oldfred recommended to create an efi partition on each drives, I decided to create such a partition at the beginning of my second drive (Drive 1) and to choose it as location for Ubuntu's boot loader.

By power on I entered the bios, inserted a gparted live CD and booted on it. First I removed the boot flag appearing on the existing efi partition (on Drive 0) used by Windows 8. Then I erased the first partition on Drive 1 (the primary partition (E.)). In the free space, I created an efi partition of 250MB (fat32), a partition for Ubuntu's root (ext4), a swap partition, a /home partition (ext4). I attributed the boot flag to the new efi partition. Then I restarted on Ubuntu's live CD. I chose a manual partitioning. I just configured and formatted the partitions / and /home. I touched neither the efi nor the windows partitions. According to the tutorial, the choice of the location of the boot loader is irrelevant since it will be automatically installed in the new efi partition. After that, I could restart Ubuntu without problem. However I was not able to restart Windows 8. Following Luis Alvarado's tutorial, I used boot-repair to cure this drawback. Now I can start both OS from the new efi partition.

This gives an clear answer to my first question. gparted should use an existing, by windows created partition to prepare the partitioning used by Ubuntu, and not create partitions from an empty space on the drive. Note that this is also coherent with oldfred's answer.

Concerning my second question (on the removing of windows 8), I have no definitive answer since I did not remove windows 8. However I guess I can do it without disturbing Ubuntu’s boot loader since the latter is on the new efi partition (I saw grubx64.efi somewhere under /boot/efi, where the new efi partition is mounted). I avoided in fact the case where Ubuntu uses the same efi partition as windows for boot. In that latter case, I guess it also works (as soon as you do not remove the efi partition but only windows OS). It would be nice to check this.