Hybrid MBR: Best way to dual boot OS X on a BIOS only machine?!

[buttcrap]

Hey guys, getting ready to lay the groundwork for a Windows 10/Yosemite dual boot here.

I have a 2011 HP DV6 with a 256gb SSD and a 1tb hybrid drive, and it's worth noting that I have an older style BIOS only system, so native UEFI/GPT booting is not an option for me. I've been doing a lot of research recently into GPT and MBR type disk formats, and obviously GPT looks all around better. I don't really care which one I use, as long as it is not a hybrid MBR. Ideally all of my disks are one or the other even if they're different, just not a mix of the two.

 

So.. As far as I can tell, here are my options:

 

 

1. Install Windows 10 MBR style, then install Yosemite using the 'Yosemite MBR Patch'. My question about the patch is this, will it force OS X to use MBR or will it just install OS X on a GPT style partition, creating a hybrid MBR? I'm assuming that it does create a hybrid, but this is something that I could not find any kind of documentation for at all. Could somebody clarify this?

 

2. Use a DUET bootloader (Clover) to boot a Windows installer, tricking Windows into thinking I'm using a UEFI system and therefore allowing me to install to GPT. This would require DUET to boot either OS, and I'm ok with that..

 

3. Install Windows 10 MBR style, use 'gptgen' to safely convert the drive to GPT and then install Yosemite, forever relying on DUET to boot.

 

4. Place the MBR boot files in a ~200mb partition on the 1TB hybrid drive instead of keeping them on the startup disk itself, creating an all GPT disk while still retaining the original boot settings. The downside to this one is that I may want more than 4 partitions on the 1tb drive, and that will never be a possibility if it has an MBR partition(as far as I can tell). But I COULD, I think, have an all GPT drive as my OS drive, and an all MBR drive for the data. As per this guide. Well, not exactly. In the guide the guy is using a USB stick, I would just use a small MBR partition on the 1tb secondary drive. I think for this one I would also need to install EFI on to the GPT disk to get into Clover? Can anyone clarify/expand on this?

 

I can't find any other solutions for this other than these 4 - if you know of one, please let me know!

 

 

Additional information:

As of right now, the SSD has a fresh copy of Windows 10 on it, and the 1tb has both Yosemite and Windows 7 on separate partitions. It's a dirty, dirty hybrid MBR, and will be wiped soon in favor of all GPT or MBR. I could of course make things easy and install one OS to one drive, but I can't get over how great it would be to have both taking advantage of SSD speeds.

 

I would also love to keep Windows 10 Fast Boot around, as it makes my boot times into Windows like 3 seconds, but if I understand right this isn't really possible using Clover.

 

tl;dr I should have bought a UEFI machine

I didn't really clarify, but I'd like to know what some more technical people have to say about this, or if there are any major advantages/disadvantages that I'm not seeing here. I know about the 4 partition limit on MBR disks, it's not a super big concern of mine as I don't think I'll need more than that on each of my drives. Which one of these is the best for this situation, or which one of these have you found the most success with in a similar situation?(Dual booting a BIOS only machine)

[artur_pt]

hello

 

u can use gpt .. and trick windows to think it as a mbr partition .. only need to prepare the 2 or more partitions with disk util.. then assign the windows one fat..

 

in windows installer change again the fat to ntfs.. and install

 

u can use clover in legacy to boot

 

good hack

[fusion71au]

@buttcrap,

 

We can frame the question another way - what bootloader are you most comfortable with?

 

If Chameleon, then you will be limited to installing on a disk with MBR or hybrid MBR/GPT partition layout ---> install Windows in legacy mode.

If Clover, you can install either on a MBR or pure GPT disk but best on pure GPT (with protective MBR) ---> best to install Windows in UEFI mode.

 

The "Yosemite MBR patch" is only needed for the Yosemite installer, to allow the install to proceed on an MBR disk.  A native OSX installer made with the "createinstallmedia" method will only allow installation onto a GPT or hybrid MBR/GPT disk.  You will have to prepare an installer with the "Basesystem.dmg" method (eg see post #1715 here), then apply the patch.  Note after OSX is installed, it doesnt care whether it is on an MBR drive or GPT drive and functions the same.  The patch also doesn't convert the target hard drive from MBR to hybridMBR/GPT.

 

Personally, I would recommend a pure GPT partition layout on all your drives (your option 2) and installing Windows in UEFI mode through Clover's legacy pathway - see @Avin7000's thread:

 

[Guide] Install Windows 8 UEFI on Legacy BIOS with Clover (and Dual boot with Yosemite)

Also How to create a Clover UEFI Windows/OSX installer.

 

 

 

@artur-pt,

 

What you are describing creates an hybrid MBR/GPT which the OP has said he doesn't want (Disk Utility converts a pure GPT disk to hybrid MBR as soon as you try to add a FAT partition.  It automatically assumes that you want a bootcamp partition to install legacy MBR windows!).

 

[liujianwei]

Because your computer(and I) is BIOS only,so MBR is needed for boot.Clover can handle GPT,so I think MBR is needed to boot Clover,and clover boot sector handle driver,it handle GPT,so you still need Hybrid MBR,because you are BIOS only.

My method is install Yosemite on GPT SSD,install Windows on MBR HDD,because clover boot my Windows DVD UEFI fail.

Apple's Boot Camp software for Intel-based Apple Macs creates a hybrid partition table to allow the booting of Windows (which at the time of Boot Camp's creation did not support GPT or EFI). In this system the protective partition is reduced in size to cover from sector 1 to the sector before the first regular partition included in the hybrid MBR. Additional MBR partitions are then defined to correspond to the next three GPT partitions.So you don't have free partition to install Windows UEFI on GPT SSD.Seems like Clover doesn't use MBR partition entry,so you can use GPT free.