I recently started playing with VM and saw that I have 2 options when creating a VM, I can use a Virtual Disk or a Physical Disk.

I belive using the physical disk would be faster and better and I would like to confirm if this is true ?

Another thing I was wondering is if I have to make the partitions myself of if the VMWare will do it for me ?

For example if I have a 500GB disk that has 400 being used by the host OS so I have 100 spare size would it let me repartition those 100 or it would either ask for the entire 100 or for me to point an already created partition to be used ?

  • If you need to move the VM to another machine then the virtual disk is the way to go.
    – hookenz
    Oct 13, 2010 at 6:58
  • I dont need to move it anywhere it is just a test host running test VMs for learning tha can be wiped clean anytime.
    – Guapo
    Oct 13, 2010 at 7:00
  • then don't worry about the physical disk feature. It's for a few specific situations and not relevant for your usage. Oct 13, 2010 at 8:32
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    @Chris it is not a worry, it is an interest to know my options, and if they will reflect on later, the computer i am using for VM inst a very good machine, would say it is a bellow average one but if there are points that i can maximize the use of its resource i don't see why not to ask and learn about the options avaiable.
    – Guapo
    Oct 13, 2010 at 8:51

2 Answers 2


We need to clarify here as there are two types of 'physical' disks referred to in a VMWare world. The first is where a virtual drive is defined within a single VM as being physical to allow for multiple VMs to access it simultaneously, these are often Raw Device Mappings to genuinely physical disks or SAN LUNs to allow for things like MS Clustering to work (i.e. where you put your Quorum and MSDTC volumes). The other type is really a hold-over from a physical-to-virtual (P2V) conversion of a legacy server/PC. VMWare kindly offer for you to simply mount a real physical drive on the host and pass it directly through to a VM for exclusive VM-to-disk use. This has sped up many complex conversions but is really only a stop-gap until admins have properly converted the drive over to a virtual one.

For both cases VMWare is not able to snapshot these disks.

It seems pointless to repartiion your host drive or to use the first physical disk option unless you actually need that functionality. What I'd suggest is that you simply let VMWare Workstation create virtual disks for you in the existing partition, this will be the simplest solution and will allow you to concentrate on learning other aspects of the software - perhaps coming back to this area later. That said if you're particularly concernted about VM performance I'd highly recommend putting your VMs on a second disk or array, but not in a separate partition of your existing disk. Oh and VMWare wouldn't repartition anyway, it's not what it does.

Hope this helps, feel free to come back with any follow up questions you may have.

  • 1
    +1 yes it does help and you actually pointed out some extra interesting information i was not aware of. I am no expert in VM in any way or was planning to become one but i felt that i need some extra knowledge about it to know that i was really doing it the right way. Once again thanks for you nice reply.
    – Guapo
    Oct 13, 2010 at 8:50
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    My pleasure, it's questions like yours that this site thrives on.
    – Chopper3
    Oct 13, 2010 at 8:56
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    :P don't worry i am sure I will bring some nice questions along my learning curve from what I am currently doing... or so I hope... hehehe
    – Guapo
    Oct 14, 2010 at 16:08

You may run into problems, like driver issues or booting issues!


I have yet to actually try this, but most would use a physical disk as a storage disk for the virtual machine. If it's for the OS then you will get the same or maybe better performance by running it as a virtual disk. I have actually seen a higher disk performance score in the Windows Experience index on a virtual machine, as opposed to the host OS index score...

If the 100GB is an unpartitioned (raw) part of the disk, then yes Vmware would partition it for you. If it's just unused space on your primary partition then you would need to shrink your main partition down to 400 and have the 100GB as raw.

If it were me, I would format that 100GB partition as an area to store the VM files and virtual disks.

Definitely read up on it before trying it.

Hope that helps

  • +1 I actually meant to say partition A using 400GB and rest of disk 100GB unpartitioned. thanks for the reply, i guess for now i will stick to virtual disk since i just began with it and still learning and maybe later move if i see that it is worthed to...
    – Guapo
    Oct 13, 2010 at 7:03

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