johnwillyums wrote:Up until recently, I had W7 on one HDD and Linux Mint on another. I would be presented with a choice at boot.
Recently I upgraded my system and now have a Z77 mobo with an EFI boot. I have installed W7 on a 128GB SSD boot drive.
When I connected my 500GB Linux Mint HDD to the system, it would not boot either OS.
In theory, the Windows 7 installation that booted before connecting the Linux disk should have continued to boot after connecting the Linux drive. My guess is that your firmware includes some sort of "helpful" auto-detection of disk type to determine its boot mode, and this became confused by the mix of GUID Partition Table (GPT) on the Windows 7 SSD and the Master Boot Record (MBR) on the Linux disk. There are some other possibilities for things that can confuse a modern firmware, though. You might be able to overcome this problem by fiddling with your firmware's settings, but unfortunately, the amount of standardization of such things (namely: none) makes it impossible to over concise advice on this score.
I've done some reading around dual booting and have heard of Gummiboot, ReFind, Elilo, Grub Legacy etc.
Thing is, these all sound too complicated to me. I don't want to try something and end up bricking my PC.
I imagine there are an awful lot of people like me, who are not tech savvy enough to risk messing around with boot loaders, boot managers, command line changes, etc
Unless the firmware is phenomenally buggy (as is the case for some Samsung laptops), a boot loader cannot brick a computer. The worst it can do is render the OS unbootable, but you should still be able to boot using an emergency disc or USB flash drive, enabling recovery.
OS installation, whether on BIOS, on EFI, or on some other type of firmware, uses a boot loader. Mint just sets up its boot loader automatically, and in most cases you don't need to deal with it explicitly, except to use it to select which OS you want to boot. Your problem is that you're switching from a BIOS-based to an EFI-based computer, which means you've got to modify your boot loader configuration.
So, are there plans afoot to simply incorporate an EFI boot manager into the install DVD? So that we can just install it, like we used to do.
It's already there. I've seen many reports of problems with Mint 14 on this score, though, so I think the Mint developers need to work on getting the EFI boot loader they use (an EFI variant of GRUB 2) to work correctly.
If I just reconnect the 500GB HDD will I be able to access it. Obviously I won't be able to access it from Windows, but will I be able to see the drive? Or will I need to do a fresh install on the 500GD HDD when it is connected up?
In theory, yes; but your first post states that you can't boot with that configuration.
In the past I have always installed Linux Mint by disconnecting the Windows drive and doing a straight forward install on the 500GB drive. Then, when I reconnect the Windows drive, I get a choice at boot, Windows or Linux. If I click Linux it takes me to GRUB and I click on Linux again and it boots.
Should I follow this method again?
Probably not. One of the quirks of EFI is that it stores boot loader information in NVRAM, and some EFIs "helpfully" delete NVRAM entries for boot loaders that the firmware can no longer find. Thus, if you start with a working Windows boot loader on one drive, disconnect that drive, install Linux on another drive, and reconnect the Windows drive, you'll end up with a system that can boot Linux but not Windows. You'll be able to fix this by futzing with the boot loader configuration, but it should
be simpler to have Windows accessible when Linux is installed. In theory, that will enable the installer to configure GRUB to boot to Windows as well as to Linux, and it will preserve the firmware's boot loader entry for Windows, so you can use the motherboard's own boot manager to select which OS to boot in case GRUB can't manage the task.
As to how to proceed, there are two broad approaches:
- Revert to BIOS-mode booting -- Most modern EFI implementations also support BIOS-mode booting. If you install Windows in BIOS mode, you'll then be able to connect your Linux disk and switch between the two OSes using a BIOS-mode boot manager (such as GRUB) or the firmware's own boot manager. This is likely to be the easiest way to go, but you'll need to re-install Windows, which means both converting the SSD's partition table from GPT to MBR and figuring out how to get your Windows installation medium to boot in BIOS mode.
- Convert Linux to EFI-mode booting -- You can re-install Mint in EFI mode or install an EFI boot loader for Linux on your computer. This may require doing an MBR-to-GPT conversion on your existing disk. (My gdisk program can do this without damaging your data, with some caveats -- see its Web page for details.)
Before you proceed, though, I recommend gathering some data to be sure you're working on facts rather than assumptions. Download the Boot Info Script
and run it from an emergency disc (like Parted Magic
or the Mint installer in its "try before installing" mode). Be sure to do this with both your Windows and your Linux disks attached. Post the RESULTS.txt file that it creates, either in code tags or as a link. That output will tell us how your disks are partitioned and how both the OSes are installed. For instance, I've been mostly assuming that Windows is currently installed in EFI mode; but it could be that it's actually installed in BIOS mode and something else is causing the system to fail to boot when you attach the Linux disk. You shouldn't proceed with any course of action until you verify or disprove this assumption.