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How to read VM hard disk content

Posted: 2. Dec 2009, 11:29
by alex5
Is there any posibility to read (only read) VM hard disk content (with snapshot data) without starting VM?

Re: How to read VM hard disk content

Posted: 2. Dec 2009, 11:52
by mpack
Please edit your profile to mention your normal host OS and typical guests. It's hard to answer questions like yours otherwise.

Re: How to read VM hard disk content

Posted: 2. Dec 2009, 12:16
by alex5
Ok, done. I don't understand how type of the used OS have an influence on posibility to read VM hard disk data (except native OS utilities). Is there VirtualBox tool for this goal? However any other ways are interesting also.

Re: How to read VM hard disk content

Posted: 2. Dec 2009, 12:19
by alex5
Of course, I don't ask about possibilities of reading Unix filesystems under Windows.

Re: How to read VM hard disk content

Posted: 2. Dec 2009, 12:36
by mpack
Ok, now that you have provided the basic data...

AFAIK, there is no tool on any host OS that will let you examine the contents of a VDI file which uses snapshots. I think the same applies to any other file format which uses snapshots.

On Linux hosts I believe tools exist which let you mount a VDI file (without snapshots) on the host.

On Windows hosts there are tools which can do it for fixed size VDI files. There are tools which can do it for fixed or dynamic VMDK files, and of course mounting a VHD as a virtual disk on the host is a feature of Windows 7 - and in fact this one might support snapshots. VBox of course supports VMDK and VHD files.

There are no tools provided with VirtualBox to do any of this.

Re: How to read VM hard disk content

Posted: 2. Dec 2009, 14:55
by alex5
Thank you very much for detailed answer. If I understand correctly, at this moment I only can export VM (when its disk exported into VMDK format) and then try to read it with third party tools? Have you plan to create native Virtualbox utility for this purpose in the future?

Re: How to read VM hard disk content

Posted: 2. Dec 2009, 15:14
by mpack
alex5 wrote:If I understand correctly, at this moment I only can export VM (when its disk exported into VMDK format) and then try to read it with third party tools?
Assuming you don't want to use fixed sized VDIs - which I can understand - then your understanding is roughly correct.
alex5 wrote:Have you plan to create native Virtualbox utility for this purpose in the future?
I am not a VirtualBox developer (this site is maintained by volunteers from the user community, not by the VBox devteam). The VBox devs generally do not reveal their future plans.

Is there some good reason you are unwilling to start up the VM? A network share would let you browse into the filesystem of a running guest, and this time it would work regardless (within reason) of which host or guest OS is used, and works even when the guest does use a Unix filesystem.

Re: How to read VM hard disk content

Posted: 3. Dec 2009, 00:49
by MarkCranness
WinMount says it supports VDI files with snapshots (I think...). It is a bit unclear about whether you can mount a specific snapshot, or the 'Current State'.

I have idly been contemplating adding VDI read & write, with snapshot support to ImDisk, which is free OS software.
Would there be much demand for that? (WinMount costs $49 and ImDisk is free.)