Dual boot issue on EFI/GPT

[vkmaheshbhat]

Hi people,
I have a new Lenovo B570 with Intel core i3-2330M, 4GB RAM and 500GB HDD. Output to parted -l is as follows:

[root@localhost liveuser]# parted -l /dev/sda
Model: ATA HITACHI HTS54755 (scsi)
Disk /dev/sda: 500GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt

Number  Start   End    Size    File system  Name                              Flags
 1      1049kB  106MB  105MB   fat32        EFI system partition          boot, hidden
 2      106MB   240MB  134MB                Microsoft reserved partition  hidden, msftres
 3      240MB   122GB  121GB   ntfs         Basic data partition             hidden
 4      122GB   227GB  106GB   ntfs         Basic data partition             hidden
 5      227GB   332GB  105GB   ntfs         Basic data partition             hidden
 6      332GB   332GB  1049kB                                                        hidden, bios_grub
 7      332GB   333GB  524MB   ext4                                                boot
 8      333GB   500GB  167GB                                                          lvm


Model: Linux device-mapper (linear) (dm)
Disk /dev/mapper/VolGroup-lv_root: 53.7GB
Sector size (logical/physical): 512B/4096B
Partition Table: loop

Number  Start  End     Size    File system  Flags
 1      0.00B  53.7GB  53.7GB  ext4


Model: Linux device-mapper (linear) (dm)
Disk /dev/mapper/VolGroup-lv_home: 108GB
Sector size (logical/physical): 512B/4096B
Partition Table: loop

Number  Start  End    Size   File system  Flags
 1      0.00B  108GB  108GB  ext4


Model: Linux device-mapper (linear) (dm)
Disk /dev/mapper/VolGroup-lv_swap: 5234MB
Sector size (logical/physical): 512B/4096B
Partition Table: loop

Number  Start  End     Size    File system     Flags
 1      0.00B  5234MB  5234MB  linux-swap(v1)


Model: Linux device-mapper (snapshot) (dm)
Disk /dev/mapper/live-osimg-min: 4295MB
Sector size (logical/physical): 512B/512B
Partition Table: loop

Number  Start  End     Size    File system  Flags
 1      0.00B  4295MB  4295MB  ext4


Model: Linux device-mapper (snapshot) (dm)
Disk /dev/mapper/live-rw: 4295MB
Sector size (logical/physical): 512B/512B
Partition Table: loop

Number  Start  End     Size    File system  Flags
 1      0.00B  4295MB  4295MB  ext4


Warning: Unable to open /dev/sr0 read-write (Read-only file system).  /dev/sr0
has been opened read-only.
Error: Invalid partition table - recursive partition on /dev/sr0.         
Ignore/Cancel? C
Model: Slimtype DVD A DS8A5SH (scsi)
Disk /dev/sr0: 610MB
Sector size (logical/physical): 2048B/2048B
Partition Table: unknown

[root@localhost liveuser]#

Well, I have installed Win7 64 bit on the 121GB partition. Now, the trouble is, when I tried installing fedora 15, I got a warning something like "You are installing on a GPT disk...(something)... This may not work". At that time, installation could go on so I went ahead and installed. But afterwards, on reboot, it never booted into linux, directly loading windows. I tried even the EasyBCD to work with the windows bootloader but no use. I even tried both the options for GRUB installation, MBR and first sector of boot partition.
Can anyone suggest a solution?
Cheers,
Mahesh

[srs5694]

If Windows is booting correctly, that means that Windows is installed in UEFI mode; however, it appears that your Fedora installer booted in BIOS mode and installed a BIOS boot loader. Thus, to boot Linux as-is, you'll need to reconfigure your firmware to boot in BIOS mode rather than in UEFI mode. This is likely to be a pain to do on a regular basis, so the best solution is probably to install a UEFI boot loader for Linux.

I've got a Web page describing various UEFI-capable Linux boot loaders here. I recommend you look at either Fedora's patched GRUB Legacy (which will boot Linux or chainload to Windows) or the combination of ELILO and rEFIt (ELILO boots only Linux, while rEFIt gives a choice of Linux or Windows). Once you understand the basics, installation is fairly straightforward, but you'll need to use some sort of emergency disc to do the work. (Perhaps you could do it from Windows, but I've never tried accessing the EFI System Partition from Windows.)

Another comment: Your /dev/sda7 (presumably Fedora's /boot partition) is marked as an EFI System Partition. This is incorrect; it's a known bug in the Fedora installer. You can correct this problem by removing the "boot flag" from within parted or by using GPT fdisk (gdisk, cgdisk, or sgdisk) to set the type code to something more appropriate, such as 8300. The latter is a better option, since parted doesn't yet support the new Linux-specific partition type code, so if you use parted, the Linux /boot partition will show up in Windows as an unformatted partition, making it easy for you to accidentally trash it in Windows.

Once you've got UEFI booting working, you can safely delete /dev/sda6, which is the BIOS Boot Partition for GRUB 2 under BIOS. This partition doesn't really do any harm, but it's unnecessary in a BIOS boot mode.

[vkmaheshbhat]

Thanks a lot for the answer mate. Excuse me for being a bit stupid with this, I understand superficially how EFI and GPT systems work but while installing, where should I install GRUB, for example? Do I (if I can) edit something in EFI tables manually to make it recognise GRUB or is it done automatically with compatible GRUB version? Because I tried today with Fedora 16 beta because it comes with GRUB2, and I had the same issue.
By-the-way great work with gdisk. Used it to change the type id.
Regards,
Mahesh

[srs5694]

An EFI boot loader resides in the EFI System Partition (ESP), in a subdirectory of the EFI directory on that partition -- for instance, in EFI/redhat (which is where Fedora places its boot loader). The Fedora installer does not give you any options on this score, AFAIK. When the installer boots in EFI mode, it does this placement automatically and correctly. It also tells the EFI about this new boot loader, so it should appear as a boot option in the EFI's own boot manager the next time you boot.

What appears to have happened to you, though, is that the Fedora installer booted in BIOS mode rather than in EFI mode. This caused it to install the BIOS version of GRUB 2 rather than the EFI version of GRUB Legacy (which Fedora still uses for EFI installations because the Fedora developers feel, as I do, that GRUB 2 is just not yet reliable under under EFI). Thus, you now have no EFI-capable boot loader installed. The easiest solution, as I wrote, is to go in with an emergency disc and install a boot loader manually. As described on the Web pages I referenced, you may need to place the boot loader in the ESP's EFI/BOOT subdirectory, under the name BOOTX64.EFI; or use some sort of firmware option to locate the boot loader manually, at least the first time you boot. This is because you cannot, when booted in BIOS mode, tell the EFI about the boot loader you've just installed, so you may need to use the "default" name for a boot loader -- EFI/BOOT/BOOTX64.EFI.

Another option is to try again to re-install everything from scratch, but be sure to get the installer booted in EFI mode. This may be possible, but you'll need to fiddle around with your firmware's boot options to figure out how to do it. Unfortunately, there's no standardization on this score, and many manufacturers provide firmware with very poor options in terms of user choice of how the system boots. Perhaps installing a boot loader, kernel, and initial RAM disk on a USB flash drive would help.

[chrismurphy]

I'm thinking that the LiveCD by default is only BIOS bootable. You can use livecd-iso-to-disk to make a USB stick that's UEFI bootable however.

Probably what happened is you booted off the unmodified LiveCD, which caused the activation of the CSM (BIOS) in your UEFI system, and that's why the Fedora installer produced a BIOS based installation of Fedora. It thinks it's on a BIOS system.

If you create an EFI LiveCD USB boot stick the Fedora installer will see your machine is UEFI and thus it will produce a UEFI installation. If you are booting off the Install DVD rather than the LiveCD, then you might need to learn more about how your UEFI system handles hybrid DVDs such as the Fedora x86_64 install DVD because it can boot either UEFI or BIOS systems.

---------- Post added at 04:55 PM ---------- Previous post was at 04:53 PM ----------

For example on Apple hardware which is Intel EFI based, starting up with the option key to get the startup disk boot menu reveals two CD/DVD icons for the Fedora x86_64 installer DVD. One is labeld "EFI Boot" and the other is labeled "Windows". Choosing to boot from the EFI Boot icon boots the hardware EFI mode and will produce an EFI based Fedora installation. Choosing the "Windows" icon boots the hardware using the CSM and produces a BIOS based Fedora installation. Presumably your system has some way of letting you choose how to boot your system when it encounters such DVDs.

[srs5694]

Originally Posted by chrismurphy

I'm thinking that the LiveCD by default is only BIOS bootable. You can use livecd-iso-to-disk to make a USB stick that's UEFI bootable however.

Perhaps; I haven't tried it. The install disc, though, is bootable in either BIOS or EFI modes. Since the goal is to install Fedora, using the install disc rather than the live CD disc makes sense. (I realize the live CD has an installation mode; I'm just saying that if it lacks an EFI boot mode, ditching it in favor of the installation disc makes sense.)

For example on Apple hardware which is Intel EFI based, starting up with the option key to get the startup disk boot menu reveals two CD/DVD icons for the Fedora x86_64 installer DVD. One is labeld "EFI Boot" and the other is labeled "Windows".

Most UEFI-based PCs have a boot option that you can get to by pressing a function key (F10, F12, or whatever), similar to the boot option on BIOS systems. Check the messages that appear on the screen as you begin to boot for a prompt about what to do. Once you're in the boot manager, you might see two DVD options, one of which boots the DVD in BIOS mode and the other of which boots the DVD in UEFI mode, although the labels might not be 100% clear.

Another option is to install rEFIt to the ESP, or perhaps to a USB flash drive. That might give you an option to boot the install disc in UEFI mode even if the firmware's boot manager doesn't provide such an option. As I wrote earlier, you could also install GRUB or ELILO in a similar way, perhaps with the kernel and initial RAM disk image off of the boot or installation disc, to get the system booted in UEFI mode. This may seem confusing or strange if you're not used to UEFI, but it's really not that hard if you understand the boot loaders. Maybe I'll add a new sub-page to my EFI boot loaders Web pages....

[vkmaheshbhat]

Thanks a lot both of you guys. I will try first to install from a x86_64 DVD and if it doesn't work (and even if it does), install maybe a patched GRUB legacy.

Maybe I'll add a new sub-page to my EFI boot loaders Web pages....

Adding a small section in your FAQ with this detail would be a great help for a lot of beginners like me.
Cheers,
Mahesh