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I've seen the following question:

What PowerShell command would you use to create a Hyper-V virtual machine?

New-VM -Name "VM Name" -MemoryStartupBytes <memory> -NewVHDSizeBytes <disk size>
New-VM -Name "VM Name" -MemoryStartupBytes <memory> -VHDSizeBytes <disk size>
New-VM -Name "VM Name" -MemoryStartupBytes <memory> -NewVHDXSizeBytes <disk size>
New-VM -Name "VM Name" -MemoryStartupBytes <memory> -VHDXSizeBytes <disk size>

Apparently the option is number 1 but why is this? why not number three a vhdx?

share|improve this question
Why does this question start with "23."? – Oliver Salzburg Jul 25 '13 at 11:15
VHDX is the new file extension and only supported on Windows 8 and Windows Server 2012. Its not evident what version of Hyper-V you are using. The other 3 commands do not even exist. Depending on the version of Hyper-V installed on the system the correct file extension would be used automatically by default. Since this could have been easily researched I have to issue a downvote. – Ramhound Jul 25 '13 at 15:39
up vote 2 down vote accepted

VHDX is the format of a virtual disk introduced by Windows 8/Windows Server 2012 (Hyper-V 3), but Powershell parameter for a New-VM (-NewVHDSizeBytes) was not changed to -NewVHDXSizeBytes.

share|improve this answer
brilliant thank you very much. what a daft thing for Microsoft to do vhd and vhdx should be defined differently in the command – topcat Jul 25 '13 at 11:26

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