How to Create a Fixed Size Hard Disk for a Hyper-V VM [Detailed]

To set up a virtual machine (VM) in Hyper-V, you need to select the type of virtual machine hard disk (VHD). The two main types that Hyper-V allows you to create are Dynamically Expandable disks (DEDs) and Fixed Size Hard Disks (FSHDs). Dynamically expanding disks grow as data is added, while fixed-size hard drives pre-allocate all storage space, which improves performance and reduces fragmentation. In this article, you will be walked through the steps to create a fixed-size hard disk for a Hyper-V VM.

Why Use a Fixed-Size Hard Disk

Before getting into the specific steps, let’s have a look at the advantages of the fixed-size disk:

✅ Higher Performance: Since space is pre-allocated, read/write speeds are typically faster than dynamically expanding disks.

✅ Reduced Fragmentation: Fixed allocation prevents fragmentation on host storage.

✅ Predictable Storage Usage: Since the full disk size is reserved immediately, there is no unexpected growth of disks.

✅ Ideal for Production Environments: Fixed disks are preferred due to stability and performance concerns.

Steps to Create a Fixed-Size Hard Disk in Hyper-V

The following provides you with the detailed steps on how to create a fixed disk in Hyper-V.

Step 1. Open Hyper-V Manager

Press Win + R, type virtmgmt.msc, and hit Enter to open Hyper-V Manager.

In the left pane, select your Hyper-V host (the machine running Hyper-V).

Click New > Virtual Machine to create a VM without adding a hard disk.

In the Connect Virtual Hard Disk, choose Attach a virtual hard disk later.

Step 2. Add a Fixed-Size Disk to the VM

Right-click the newly created VM > Settings.

In the SCSI Controller tab, choose Hard Drive > Add.

Then click New to open the New Virtual Hard Disk Wizard.

Step 3. Select Disk Type

You’ll be prompted to choose a disk type.

• Fixed Size – Pre-allocates the entire disk space.
• Dynamically expanding – Starts small and grows as needed.
• Differencing – Used for parent-child disk relationship.

Select Fixed Size and click Next.

Step 4. Name and Save the Disk

Enter a name for your virtual hard disk.

Choose a location where you want to store the VHD file.

Step 6. Confirm and Create the Disk

Review your settings in the summary window.

Click Finish to create the fixed-size VHD.

Free and Efficient Backup Software for Hyper-V VM Protection

Here introduce you a free Hyper-V backup tool – AOMEI Cyber Backup, it is designed to back up Hyper-V with flexible backup strategies and restore the Hyper-V VM within a few clicks. This tool can protect VM data continuously and reduce business downtime.

With this professional tool, you can also enjoy:

• Easy-to-use: Backup and restore the entire VM with only a few clicks, without any complicated configuration.
• Centralized VM Backup: You can back up multiple Hyper-V/VMware virtual machines at the host level without installing an agent on each VM and simply manage the tasks through the central console.
• Automate VM Backup: Schedule VMware ESXi/Hyper-V backups to run the backup task automatically, reducing human errors and offering regular backups.
• Quick Recovery: You can restore Hyper-V backup with a fast speed to save your time.

3 Easy Steps to Create Automatic Backup Tasks of Multiple VMs

Step 1. Access to AOMEI Cyber Backup, navigate to Source Device > Hyper-V > + Add Hyper-V to add a host. And then click … > Bind Device.

Step 2. Navigate to Backup Task > + Create New Task, and then set Task Name, Backup Type, Device, Target, and Schedule.

• Device: select VMs on the host to backup in one backup task.
• Target: You can select to back up to a local path or to a network path. Used paths will be saved in Favorite Storage for handy selection.
• Schedule: You can choose to perform full or incremental backup and automate execution daily, weekly, or monthly according to the frequency you specify.

Step 3. You can select Add the schedule and start backup now, or Add the schedule only.

Conclusion

Creating fixed-size virtual hard disks in Hyper-V ensures a simple and effective way to improve performance, reduce fragmentation, and predictable storage usage. It is the preferred choice for production environments and workloads that require consistent disk performance. You can confidently use optimized ground storage to manage virtual machines.