Hyper-V – Creating a large fixed disk – EXTREMELY Slow

hard drivehyper-vvirtual-machines

Hey everyone, after posting another question here, it seems I have to create a fixed disk in order to get one 700GB.

I have shut down the machine (which basically has nothing on it), and gone to convert to a fixed disk. It is going EXTREMELY slow – if my calculations are correct at the rate its going it will take ~2 days to complete. Its been going for about 6 hours and its about 10% complete. I'd like to continue setting up my server and start using all of the space.

Is this normal? How can I speed this up???

Thank you,

Best Answer

By default, when you create a VHD, the creation process zeros out the data as it builds the file.

MS released a tool to create VHD's very quickly which bypasses the zero out process.

Example

To create a 100 GB VHD, use something like:

.\VhdTool.exe /create '.\Virtual Hard Disks\SRV-EXCHANGE_Backup.vhd' 107374182400

It will take only seconds to complete.

Output

PS C:\VMStorage> .\VhdTool.exe /create '.\Virtual Hard Disks\SRV-EXCHANGE_Backup.vhd' 107374182400
        Status: Creating new fixed format VHD with name ".\Virtual Hard Disks\SRV-EXCHANGE_Backup.vhd"
        Status: Attempting to create file ".\Virtual Hard Disks\SRV-EXCHANGE_Backup.vhd"
        Status: Created file ".\Virtual Hard Disks\SRV-EXCHANGE_Backup.vhd"
        Status: Set the file length
        Status: Set the valid data length
        Status: VHD footer generated
        Status: VHD footer written to file.
        Status: VHD header area cleared.
        Status: Complete
PS C:\VMStorage>
Related Topic