I'm about to scrap my ASUS ultrabook since I'm about to receive a package (Sager gaming powerhouse notebook). In the short term I plan to dual boot Windows and Linux on that PC, but longer-term I'm transitioning to running Linux as my main OS. I'll be running Windows in a hypervisor-like environment. With a bit of complexity i can pass-through one of the NVIDIA graphics cards to the hypervisor, while giving Linux exclusive control of the other card. With this setup you can get near-native performance in games without actually dual-booting. I trust Linux to manage a Windows VM, but not the other way around. I just want to remain immersed in a Linux environment without constantly having to dual-boot to play games. I'd rather avoid WINE because it's not mature enough to run many of the latest AAA titles. Another advantage of booting from a containerized image is that I can keep the 2 OSes nicely isolated from each other (in part to prevent Windows from mucking around where it shouldn't, like Linux's stuff), and Linux remains in control.
This brings me back around to the issue of either booting Windows in a VHD or raw disk image located on a ext*(4 preferred) partition. If I have to create an NTFS volume, then I might as well dual boot, because this basically defeats the purpose of what I'm trying to do, since the volume Windows' image is contained in isn't ext*, and it's easier to just natively boot Windows on NTFS anyway.
I realize that Windows expects its' VHD/disk image to be on NTFS, because when real mode passes into protected mode it will try to rediscover the image as well as the volume that image is located on, and if it finds an unrecognized FS then it will panic. I've also read about kernel mode and user mode drivers, I'm guessing that for Windows to boot from an image on ext*, there will need to be a kernel mode driver that loads early enough in the booting process. I'm not sure if Ext2Fsd fits the bill, since it seems to be partly dependent on its' GUI and services, etc, although it does seem to be the best option overall.
I'm looking into the IFS option, since it provides a kernel mode driver for ext2/3 but not ext4, although this doesn't necessarily mean things will work out.
A few questions:
1. Does the ext* partition (itself, not Windows' image) need to be writable, or is read-only good enough? The disk image itself does of course have to be writable for Windows to run from it, but the underlying partition shouldn't need to be writable if the disk image is of a fixed size, already committed to disk, and preferably contains no Windows boot files. IFS provides read and write access but only for ext2/3, not ext4.
2. How would I go about integrating the IFS driver into the booting procedure? Do I need to embed it into a WIM then use that WIM to install Windows? Or does the driver only need to be integrated into an already installed Windows? How can I ensure and check that the booting process is making at least trying to make use of the driver, and that ext* partitions/volumes are accessible during this time window?