[jr2]

Has anyone heard of a way to create a virtual filesystem in a regular file in NTFS and boot from it?

Scenario:  I want to try Windows 8 pre-release and really don't want to play the re-partitioning game, especially since I might just delete the thing after I'm done playing with it.

Basically, I'd like to be able to mount <VirtualWinDOwS8filesystem.img> as Windows 8's drive C:, and (preferably) still be able to see the actual real partition as Windows 8's drive D: -- I want to create a boot menu entry either in GRUB or the Windows 7 boot loader menu to boot from the file.  Then, when I'm done, I just remove the entry and delete the file.

Painless.

Is it possible?  If so, has anyone created a free / and hopefully open-source way of doing this?

I could just use a virtual box I know, however that isn't the same as running native.  I want to see how things run (speed and driver-wise) as they actually would, not on generic virtual devices.

[Ghostavo]

If you must know, booting from a virtual hard drive is not much fun either regarding performance.

Each time I tried to run Wubi instead of creating a partition for Ubuntu, things slowed to a crawl.

I'd advise you to just shrink a partition and when you are tired of it, to just extend the partition back. Just don't forget to fix the bootloader.

P.S.
Windows 8 boot loader is really pretty. 

[jr2]

Hmm, true, WinDOwS can now actually shrink and grow partitions, right?  I forgot about that...  However, if my Linux partition becomes unbootable, I'd not be surprised... M$ will almost definitely re-write the boot sector without bothering to ask.  I have to go look up the commands to back it up and restore it.  Then look up how to insert the Windows 8 boot code... is it the same as Vista/7's boot code?  If so, I can just edit the 7 boot menu to include 8.

[Nuke]

when i want to do a dual boot i just get one of my older hard drives off the shelf and install the new windows to that. i physically disconnect my other drives during the install. once the system is installed i hook the other drives back up then use the bios boot menu (f11 on my system) to select which drive to boot from.

[jr2]

Yeah, that would be easiest... except I'm using my laptop.

[LHN91]

You *MIGHT* be able to set up Windows 8 on an external USB hard drive, provided you can convince the installer to install to the drive or otherwise get Windows onto the drive, and then set the system to boot from USB. Of course then you're dealing with relatively severe drive-access speed issues, but at least you'll get the rest of the experience (driver compatibility and whatnot).

I may also be spouting tons of BS. I admittedly haven't tried to do this. But, theoretically this should be possible.

[jr2]

FYI, to backup your boot sector and restore it:  (from linuxconfig.org, article here)


Linux Backup Restore Destroy and Install MBR - Master Boot Record
Last Updated on Friday, 09 April 2010 08:41

Here are some usefull hints on how to Backup Restore Destroy and Install MBR on linux. If the need comes to backup, restore and destroy your MBR you can use a dd command to do that job. First we need to find find our storage device to backup MBR. To do that use a command:

Code: [Select]

fdisk -l Let's assume that the storage device we want to work with is /dev/hdb.
WARNING: DO NOT COPY AND PASTE COMMANDS FROM THIS PAGE UNLESS YOUR DEVICE IS ALSO /dev/sdb !!
1. BACKUP MBR
To backup Master Boot Record ( MBR ):

Code: [Select]

# dd if=/dev/sdb of=my.mbr bs=466 count=1where my.mbr is a file where we would like to store our MBR backup.
2. RESTORE MBR
To restore a MBR we need to just switch the order of input and output files.

Code: [Select]

# dd if=my.mbr of=/dev/sdb bs=466 count=13. DESTROY MBR
If you from any reason want to destroy your MBR us as a input file /dev/zero:

Code: [Select]

# dd if=/dev/zero of=/dev/sdb bs=466 count=14. INSTALL MBR
Installing MBR can be very useful especially when creating linux USB boot sticks. To install MBR from scratch we can use install-mbr command found in mbr package:

Code: [Select]

# install-mbr /dev/sdb

[Achillion]

I don't think what you're suggesting in the first post is possible. I think your best bet is Virtual box, even though you explicitly said you don't want to.
Something less painless is what Nuke suggested. Even on a laptop, disconnecting the HDD is simple and you can just use an external drive to play around.

I don't see how you would be able to boot animage of a partition without loading an OS first.

[jr2]

Yeah, i know you can pop the hard disk out easy... I was just hoping for even easier if anyone knew how. 

[Ghostavo]

I don't think what you're suggesting in the first post is possible. I think your best bet is Virtual box, even though you explicitly said you don't want to.
(...)
I don't see how you would be able to boot animage of a partition without loading an OS first.

Check wubi amongst other things.

[jr2]

Checked wubi on Wikipedia, found link to http://sourceforge.net/projects/grubed/ :

A universal Operating System Installer for Windows. It installs any Operating System with inside of Windows. Works for all versions of Windows.

Am researching more now...

[Nuke]

Yeah, that would be easiest... except I'm using my laptop.

you dont by chance have an esata port do you? if you did, well you wouldnt have much issue with speed and can use a sata drive in a sata enclosure with no performance loss.

[jr2]

I do have an esata port.  I just moved, however, and my esata external enclosure is... well, in a box... somewhere. 

[Nuke]

well time to start digging

[Achillion]

I don't think what you're suggesting in the first post is possible. I think your best bet is Virtual box, even though you explicitly said you don't want to.
(...)
I don't see how you would be able to boot animage of a partition without loading an OS first.

Check wubi amongst other things.

Well there you go then. I always considered Wubi to be closer to a VM than what the OP was asking. I stand corrected once again.
It's actually exactly what the OP was asking.
The wonders of modern technology ...

[Nuke]

i saw a cool piece of tech on hack a day awhile back, essentially a usb flash drive which also emulates optical drive hardware with an fpga so that it can boot an iso from flash as if it were a cd/dvd. not sure if something like that would support a hard disk image format. of course it was a prototype for a commercial product and i think il have to dig around later for a linky.

i figure for something like this to work entirely in software you would need some kind of custom boot loader that can boot multiple oses from either a physical drive or file. but that sounds like a really convoluted and troublesome way to work around something you could do with hardware.

[pecenipicek]

i figure for something like this to work entirely in software you would need some kind of custom boot loader that can boot multiple oses from either a physical drive or file. but that sounds like a really convoluted and troublesome way to work around something you could do with hardware.

why are you describing GRUB as something that doesnt exist?

[Nuke]

of course grub can do it, but there was another boot loader that had a nice front end and could natively boot into any existing os that you could think of. cant recall what it was. i keep saying i want to set up one of these bootloaders, but then i realize how much i dispise multi-boot configurations.

[jr2]

Well, there is PLoP and GAG... not sure if they support this now, but they didn't used to... although they did support some pretty neat options, esp. plop.

http://plop.at

http://gag.sourceforge.net