Understanding virtual
disk formats
Windows
Server 2016 Hyper-V supports two kinds ofVirtual Disk：VHD
and VHDX.
VHD
- Maximum support to 2TB
- Compatible with all versions of hyper-v
VHDX
- Only support Windows Server 2012 R2 or later and Windows 8.1 or later
- Maximum support to 64TB
- Support 4KB logical sector
- larger block（Up to 256 MB）
Creating a Virtual Disk
Windows Server 2016
Hyper-V provides several ways to create virtual disk files. You can create them
while create a new Virtual Machine. Or you can also create them using the New
Virtual Disk Wizard. Or you can create them using Windows PowerShell.
Creating
a new virtual disk in Hyper-V Manager
Open
Hyper-v Manager, Right-click the Hyper-v Server，Select
New | Hard Disk. Or from the Action menu，select New | Hard Disk.
Click Next
Select one of the
following disk format options:
VHD: Create a virtual hard disk with less than 2TB and highly
compatibility
VHDX: Create a virtual hard disk with greater than 2TB
VHD Set: It's a share Virtual Hard Disk. You can share virtual disk files
between multiple virtual machines. Used for failover clustering.
Then Click Next
Select one of the
following disk type options：
Fixed Size:The
Virtual Hard Disk file size is the same as the Virtual Hard Disk space size.
Such as, a Virtual Hard Desk size is 50G，the VHD or VHDX file size is 50G.
Dynamically Expanding: Virtual hard disk file starts small, with more and more data
written, virtual hard disk file is also growing, until it reaches the size of
the virtual hard disk space.
Differencing: It
is a child virtual hard disk file that is associated with a specific parent
virtual hard disk file. All system changes will be written to the child virtual
hard disk file.
Then Click Next.
Note
It is recommended to
use the Fixed Size in production environment. While the Fixed Size allocates
all size all at once, waste of disk space, but it provides the best
performance.
The
Dynamically Expanding while saving space, but their continued growth will have
an impact on performance，and also Over-allocation
physical disk space.
The Differencing is
more suitable for scenes that require frequent return to a certain state of the
system.
But it is useful to
have Dynamically Expanding and Differencing in test environments
Specify
a filename for the Virtual Hard Disk in the Name text box，If necessary, Specify a Non-default location for the file.
Select and
configuration one of the following options:
Create A New Blank Virtual Hard Disk: Create
a new Virtual Hard Disk and specifie the size.
Copy The Contents Of The Specified Physical Disk: Select one of the physical hard disk in the computer and copy its
contents to the new Virtual Hard Disk.
Copy The Contents Of The Specified Virtual Hard Disk: Select an existing Virtual Hard Disk file and copy its contents to
the new Virtual Hard Disk.
Then Click Next
Click Finish
Creating a new virtual
disk using Windows PowerShell
You can create a new
virtual hard disk files using New-VHD cmdlet in Windows PowerShell
Path: The store path of the Virtual Hard Disk
Test.VHDX: The Name and format of the Virtual Hard Disk. The extension name you specify for the filename determines the
format（VHD or VHDX） of the virtual disk.
Dynamic: Create a dynamic extended virtual disk.You can use Fixed and
Differentiating to create a virtual disk of Fixed size or difference.
SizeByts：Specify
size of Virtual Hard Disk
You
can also specify block and logical sector size using BlockSizeBytes and LogicalSectorSizeBytes parameters
