How to Add or Remove a Physical Hard Disk for Hyper-V Virtual Machines

This guide walks you through each step for adding or removing a hard disk for Hyper-V virtual machine . You may be considering this for many reasons, not least of which is reallocating resources to improve operational efficiency.

This is where we come in. We’ve made this Hyper-V disk management guide as easy to understand as possible to ensure smooth operation and prevent configuration errors.

Why add or remove physical hard disk for Hyper-V virtual machine

Are you considering a Hyper-V physical disk passthrough? This feature allows a virtual machine to directly access a physical hard disk, thus “passing through” the host’s file system. Some reasons to consider adding a physical disk to Hyper-V include eliminating the overhead costs associated with virtualization layers, reducing CPU usage, and providing faster data transfer speeds.

Still, some experts argue against using physical disks, particularly for backup purposes, as they can make it more difficult to migrate between machines than VHD files. Physical disks attached to a single virtual machine are also—quite naturally—inaccessible by other VMs simultaneously.

Nevertheless, we recommend carefully planning your Hyper-V storage configuration based on your specific needs and IT budget. Diligent planning on how to attach a physical drive to a Hyper-V virtual machine can benefit your organization in several ways, especially if you have demanding I/O requirements.

Step-by-step guide on adding or removing a physical hard disk to Hyper-V virtual machine

Before integrating a physical hard disk with a Hyper-V virtual machine, ensure the following prerequisites are met:

• System requirements: Confirm that your host system meets the hardware and software specifications for Hyper-V. This includes a supported Windows operating system, sufficient memory, and a compatible processor with virtualization extensions enabled.
• Administrator privileges: Make sure that you have the necessary privileges to apply changes on the host machine. We recommend double-checking that the physical disk is not being used by another application or operating system as well.
• Disk preparation: Format or wipe the physical disk as needed. You should also prepare the disk for your specific needs, whether that’s initializing it with the correct partition style (GPT or MBR) or verifying the connection type (e.g. SATA, SCSI).

Now, you can begin either adding or removing a physical hard disk.

Adding physical hard disk to Hyper-V VM

Option 1

1. Launch the Hyper-V Manager. Locate the VM you wish to configure from the list.
2. Right-click on the VM and select “Settings” from the context menu.
3. From the Settings window, navigate to the “SCSI Controller” or “IDE Controller” section (depending on your setup). Click “Add” and choose “Physical Hard Disk”.
4. From the dropdown menu, select the physical disk you wish to use. Ensure that the disk is offline.
5. Start the VM and log onto its operating system. Use the OS’s disk management tools to verify that the physical disk is detected and accessible.
6. Format or partition the disk within the VM as needed.

Option 2

1. Open Disk Management (diskmgmt.msc).
2. Right-click on the online disk you want to add to the VM and select “Offline”.
3. Once the disk is offline, open the “Settings” window of the Hyper-V to which you want to add the disk.
4. Navigate to “SCSI Controller”, select “Hard Drive” and click “Add”.
5. Select “Physical Hard Disk” and choose the disk you want to add from the dropdown menu.
6. The disk should now be available to access in the virtual machine.

Removing physical disk from Hyper-V virtual machine

Option 1

1. Log into the virtual machine and use the OS’s disk management tools to eject or unmount the disk safely.
2. Open Hyper-V Manager, right-click on the VM you wish to remove, and select “Settings”.
3. Navigate to the SCSI or IDE controller where the physical disk is attached. Select it and click “Remove”.
4. After removing the disk from the VM, return to the host’s Disk Management tool. If you plan to reuse it elsewhere, bring the disk back online.
5. Verify that you have removed the physical disk. Ensure that no applications or services within the VM are attempting to access the removed disk. This prevents errors or performance issues.

Option 2

1. Go to the Hyper-V virtual machine from which you want to remove the physical disk. Click “Settings”.
2. Once in the Settings window, select the disk you want to remove under “SCSI Controller” and click “Remove”. Press “Ok”.
3. The disk will now be removed from the virtual machine.
4. Open Disk Management.
5. Right-click on the offline disk you removed and revert it to “Online”.

6 Best practices when performing a Hyper-V physical disk passthrough

1. Plan for scalability:A Hyper-V physical disk passthrough means a VM exclusively uses the disk, which limits its portability. It’s wise to document your disk configurations and ensure they are compatible with future hardware upgrades. We recommend having a well-documented setup to ensure smooth transitions during hardware changes.

2. Monitor regularly: Monitor disk health and performance using Hyper-V management tools like NinjaOne. Regular maintenance helps you proactively identify potential failures and security vulnerabilities before they impact your VMs.

3. Balance workloads:Avoid overloading the host machine to prevent performance issues.

4. Implement redundancy measures: To prevent disk failures for business-critical VMs, we recommend implementing redundancy measures, such as RAID configurations or replications. Avoid relying solely on a single physical disk.

5. Consider testing in a controlled environment: Before deploying changes to production systems, it’s a good idea to test disk configurations in a testing environment to identify potential compatibility or performance issues.

6. Choose the appropriate disk type: Make sure you optimize the right disk type for the specific use case. For example, use an SSD for high-speed access or HDD for archival purposes. We’ve written a more in-depth guide on choosing the right disk type (SSD vs HDD vs SSHD) here.

Troubleshooting common issues

Managing Hyper-V physical disks should be a simple enough process. However, if you encounter issues, consider the following troubleshooting steps:

• Disk not recognized by Hyper-V: This happens when the disk is still “online” in the host OS. To resolve this, ensure the disk is offline while performing a Hyper-V physical disk passthrough. Likewise, check physical connections, including cables and ports.
• Performance issues: Use a monitoring tool to check the disk’s I/O performance. If it is insufficient, consider upgrading to a higher-speed drive.
• Dependency errors during removal: Before detaching a disk, ensure all services and applications within the VM have stopped accessing it. You can confirm this by using a task manager or monitoring tool.
• Disk access denied: Ensure you have the administrative privileges to add or remove a Hyper-V physical disk.
• Host OS fails to detect disk after removal: Restart Disk Management and rescan for disks. If the problem persists, check the hardware connections and perform a diagnostic.

Using this Hyper-V disk management guide

Managing physical hard disks within Hyper-V environments requires careful preparation and attention to detail. Despite some experts discouraging performing a disk passthrough, you may want to add or remove a physical hard disk from a Hyper-V virtual machine to allow faster access to large data sets. Organizations requiring higher I/O performance may also want greater control over their storage allocation and choose to use a physical hard disk compared to solely relying on a virtual hard disk.

A robust Hyper-V management software like NinjaOne makes monitoring and managing your IT infrastructure much easier and more efficient. If you’re ready, request a free quote, sign up for a 14-day free trial, or watch a demo.

Frequently Asked Questions (FAQs)

1. Can I use a USB drive as a physical disk for a VM?

Yes, but it is not recommended. Keep in mind that a USB has limited space and may affect the performance of your VM. USB drives are better suited for non-critical tasks.

2. What happens if I remove a disk without ejecting it first?

You run the risk of data corruption or errors. It’s important that you always follow safe removal practices to protect data integrity.

3. Is physical disk passthrough suitable for shared storage?

No, physical disks assigned to a single VM cannot be accessed by multiple VMs simultaneously. Use network-attached storage (NAS) or storage area networks (SAN) for shared access.