Using a DMG file as hard disk in Parallels

[ppcaric]

Hi.
Is it possible to use a DMG file as hard disk within Parallels?
I try to better explain what I need and why...

I'd like to be able to create a DMG file within MacOS (maybe even an encrypted one, why not? ) and to specify it to be seen as a hard drive from Windows XP (or from any other guest OS) within Parallels.

This would be great for many reasons:
- use the "drive" as the data repository for the guest OS
- easily backup changes in the data without having to backup the entire system drive
- access the data within the "drive" from MacOS without even having to boot the guest OS
- same as above even in case the guest OS boots no more (data recovery)

DMG files can be already mounted as CD/DVD in the virtualized OS, so it shouldn't be much different to have this option for hard drives as well.
Is it already possible? How?
If not... pleaaaaase include this possibility in future releases. Thanks!

 

[Ynot]

Ufortunately it is not possible now. May be it can be possible later, but i can not promise that to you.

 

[aguydude]

It is already possible to mount an .hdd file. I've done this before with success in the past. It will only work with .hdd files that are not expanding.

I have been working on this for the last few days, and today I have a partial solution.

For pure off-line access to the file, run the following command. This will only work if your *.hdd image file is a "plain virtual hard disk". If it is not one already, then you need to convert it to one with the Parallels Image Tool.

hdiutil attach -imagekey diskimage-class=CRawDiskImage myfile.hdd

Since the plain image files are just iso images, then the above command will mount any filesystems that are found in the image. The example that I used for testing was a fat12 filesystem for a Dos 6.22 virtual machine that I have installed. If Mac OS X can recognize the file format, then it should get mounted. You can play around with the other hdiutil options,
man hdiutil, for ways to alter the behavior further.

I tried to get hdiutil to work with one of the expanding images, but non of the diskimage-classes were working. Someone else may have better luck.

Changes in the mounted filesystem, at least for my tests, do not seem to take effect until the filesystem is unmounted. So you will want to avoid having the filesystem mounted while Parallels is using it.

It would be nice to have real-time read-write access, but for now, I am happy with offline access.

I hope this helps.

 

[Rachel Faith]

That sounds pretty neat. So you are saying that OSX can read and write to the HDD without windows actually running (in Parallels or other)? Does that work for NTFS or just FATxx ?

 

[aguydude]

That sounds pretty neat. So you are saying that OSX can read and write to the HDD without windows actually running (in Parallels or other)? Does that work for NTFS or just FATxx ?

No. OSX can read the HDD without windows actually running. I don't think the resulting image is writeable. Not sure which FSs are supported.