read-only image

[comptekki]

I can only see references to needing read/write privs on images for parallels to work. Is there a way to allow users to run windows in read-only mode so that the os is refreshed (pristine) on reboot - virtual pc could do this or installing deepfreeze (for windows) can do this. If not, any plans for allowing this?

thanks.

 

[joem]

Right now, Windows' hard disk must be read write. This is a Windows limitation. If it weren't for this requirement, it would be possible to have a Windows live CD, which would be a very good thing, and go a long way towards eliminating some real nasties such as rootkits, but alas, Windows requires write access.

To allow read only, I suppose one could create a shadow disk to hold changes that could be deleted as a rollback. The shadow technique goes back to the 1960's when some filesystems stored changes for efficiency (disks were slooooooww) and to allow reverting to earlier versions of files.

 

[rachaelr]

VMWare allows this - the ability to not save any changes to the image.
Not too sure how they do it - think they store the disk changes seperatley somehow then throw the changes away.

I used to use that functionality with VMWare Server, for test machines, esp if i had one that i'ld proved a bug on (so the devs couldn't mess up my bug!).