I am playing around with firadisk and grub4dos to load a WinXP-Image to RAM and boot from it. I'm using virtualbox for my experiments. I found interesting tutorials about it, here on reboot.pro.
However, there are some things I still don't understand. My Windows is booting up but crashes after a few seconds. Before that happens, I can see the desktop and acces drives, though I'm still not sure if C:\ is from RAM or from the real harddrive.
1.) Because I'm using a special-configured XP in Vbox, I can't use the VHD-method, as often suggested. The partition-size is about 3,15 GB but the vbox-image is set to 10 GB dynamic-space. So after conversion to VHD or img, I would get a 10GB file, unsuitable for grub4dos.
2.) Therefore I made a 2nd partition in Vbox, booted with partedmagic-live-cd and copied the first 3152 MB from partition1 to an image-file on the 2nd partition. I did that to include MBR, partition-table and PBR into the image.
3.) Gparted can't read the image-file afterwards, because the partition-table is wrong. I then used testdisk to recover the partition-table in the image-file because now there is only one partition inside the file, instead of two at the origin. However, testdisk is doing it wrong for some reason. The found partition is a few MB too big in size.
4.)grub4dos is throwing errors because of this. XP is booting into RAM but, as mentioned before, is crashing after a while.
5.)I then booted with a MiniXP-live-cd to run DiskGenious and load the image-file. The program identified partition-table-errors and fixed them. Afterwards, grub4dos was not throwing errors anymore. However, XP-from-RAM still is crashing...
Forgot to mention: I did install the firadisk-driver in XP, before creating the image.
What I don't understand:
1) Do I need to configure firadisk somehow, in addition? I found some registry-values in some tutorials, to tweak around with. However I don't know if they apply for Ramdisk-usage. Shouldn't firadisk detect a grub-ramdisk by itself, after bootup?
2) Why is there a disc-image neccesary? Just using a partition-image with a bootloader in PBR would make things a lot easier.
3) I found something about the creation of a small ramdisk in grub4dos just to hand-over some configuration-options to firadisk. Basically they are the same options, someone can configure with the registry-tweaks. The small-ramdisk did not work, unfortunately. Grub4dos complains about a unknown device when trying to create the ramdisk. Can show you the command-line later.
4) The reg-key for mounted-devices (HKLM\SYSTEM\MountedDevices) holds signature and an offset of a volume. Some tutorials recommend replacing this key in the image file with the data from the image file. How do I get signature and offset from the image-file? Shouldn't they be identical as signature and offset from the original hdd?
I can give more details upon request, especially the menu.lst. Right now, I'm on a different computer, the text already got too long and it's really late already.