Access Physical Disk in VirtualBox- Desktop Virtualization Software

November 16th, 2009

Dinesh

Access Entire Physical Disk

This step by steps method explains how you can access physical disk in desktop virtualization software Sun VirtualBox. Unfortunately this cannot be done easily as how to access physical disk in VMware workstation.

Some commands and hard drive mapping are included in this access physical in Sun VirtualBox process.

You can access host computer’s physical hard disk partition also in this method. This access method is called ‘Raw Disk’ access. Read more about what is Raw Disk

Access Physical Disk in VirtualBox Desktop Virtualization Software

Before start the procedure, let me explain how it’s going to work.

As I said earlier, it’s not easy as giving access to physical disk in VMware workstation. Sun VirtualBox desktop virtualization software can access on storages added in ‘Virtual Media Manager’. To know more about Virtual Media Manager in Sun VirtualBox, click here how you can access VMDK file in VirtualBox.

You can’t add host local physical entire disk or any partitions easily like VMware workstation. We have to create a configuration VMDK file for the host entire physical disk or partition. Then add this VMDK in Virtual Media Manager. Then allocate the disk to any Virtual Machine in VirtualBox.

Ok, now let’s start the steps,

How to Access Entire Physical Disk from VirtualBox

1) Open Command prompt in Host computer then go to the Sun VirtualBox installation folder, in this case example is, ( This is on your Host computer where you installed Sun Virtualization software, NOT in the Virtual Machine)

G: \Program Files \Sun \VirtualBox

2) Type: ( This command for access entire physical disk as Raw Disk)

VBoxManage internalcommands createrawvmdk -filename c: \Users \sunuser \.Virtualbox \VDI \mydrive.vmdk -rawdisk \ \ . \PhysicalDrive0

c: \Users \sunuser \.Virtualbox \VDI \mydrive.vmdk : Location and ‘ mydrive.vmdk’ is the configuration VMDK file of your entire physical drive.

Do not think that new VMDK file will take huge size as your physical disk size. It’s just a 1KB size file. After you added this file to Virtual Media Manager, then you will get the full size of physical disk.

\ \. \PhysicalDrive0 : is the physical drive of host computer. 0,1, 2 numbers can be seen from Disk management in Windows OS under Computer Management. You insert the number as required physical disk number, normally starts with 0.

3) Command will a successful message if all OK, as shown above.

4) You can confirm that command worked correctly by visiting the location of VMDK file created.

5) Now, Open Sun VirtualBox, and go to Virtual Media Manager.

6) Add the newly created ‘mydrive.vmdk’ under hard disk. Click here to read more about how to add VMDK file in Sun VirtualBox

7) Add the newly added hard disk to your virtual machines in Sun VirtualBox and start accessing them from Virtual Machine Guest Operating system.

How to Access Partitions of Physical Disk from VirtualBox

To access specific partitions of host physical disk from VirtualBox, run the same command with additional switches,

VBoxManage internalcommands createrawvmdk -filename c: \Users \sunuser \.Virtualbox \VDI \ mydrive.vmdk -rawdisk \ \. \ PhysicalDrive0 -partitions 1,3

1,3 : are the partitions numbers of PhysicalDrive 0. It will allow you to access the first and third partitions of the physical drive.

This command also will create a VMDK file and you can access the drives as explained in first method.

Important Note about Raw Disk Access in VirtualBox

VirtualBox can also present either entire physical hard disks or selected partitions thereof as virtual disks to virtual machines.

With VirtualBox, this type of access is called “raw hard disk access”; it allows a guest operating system to access its virtual hard disk without going through the host OS file system. The actual performance difference for image files vs. raw disk varies greatly depending on the overhead of the host file system, whether dynamically growing images are used and on host OS caching strategies. The caching indirectly also affects other aspects such as failure behavior, i.e. whether the virtual disk contains all data written before a host OS crash. Consult your host OS documentation for details on this.

Warning

Raw hard disk access is for expert users only. Incorrect use or use of an outdated configuration can lead to total loss of data on the physical disk. Most importantly, do not attempt to boot the partition with the currently running host operating system in a guest. This will lead to severe data corruption.

Raw hard disk access — both for entire disks and individual partitions — is implemented as part of the VMDK image format support. As a result, you will need to create a special VMDK image file which defines where the data will be stored. After creating such a special VMDK image, you can use it like a regular virtual disk image

Access to entire physical hard disk

While this variant is the simplest to set up, you must be aware that this will give a guest operating system direct and full access to an entire physical disk. If your host operating system is also booted from this disk, please take special care to not access the partition from the guest at all. On the positive side, the physical disk can be repartitioned in arbitrary ways without having to recreate the image file that gives access to the raw disk.