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Guapo
Asked: 2010-10-13 22:29:43 +0800 CST

VMWare Workstation virtual vs physical disk?

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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 ?

performance hard-drive vmware-workstation virtual-disk

2 Answers

  1. Best Answer

    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.

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

    http://www.vmware.com/support/ws55/doc/ws_disk_dualboot_scsi_issues.html

    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

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