SOLVED: Is It Safe To Reduce The Size a Virtual Disk in VMware If It Has Not Been Expanded in Windows Disk Manager?

We had a client who accidentally expanded the volume size on a VMware disk and then wanted to undo that change. Specifically the client had used vmware cloud director to expand the size of a disk but caught their mistake right away and had not expanded the volume in Windows Disk Manager yet.

Reducing the size of a virtual disk in VMware Cloud Director after it has been expanded can be quite risky, especially if the partition has not yet been expanded in Windows. Here are a few key points to consider:

1. Data Integrity: Reducing the size of a virtual disk can lead to data loss if not done correctly. The data within the partition might be located in the space that you are trying to remove
2. Unsupported Operation: VMware does not natively support reducing the size of a virtual disk directly. You would typically need to use third-party tools or VMware Converter to achieve this
3. Backup: Always ensure you have a complete backup of your virtual machine before attempting any disk size modifications

If you still need to proceed, the recommended approach would be to use VMware Converter to create a new virtual disk with the desired size and migrate the data over to it.

VMware Converter, also known as VMware vCenter Converter Standalone, is a powerful FREE tool that allows you to convert physical machines (both Windows and Linux) and other virtual machine formats into VMware virtual machines. Here are some key features:

• P2V and V2V Conversions: It supports both Physical-to-Virtual (P2V) and Virtual-to-Virtual (V2V) conversions, making it versatile for various migration needs
• Non-Disruptive Conversions: The tool allows for hot cloning, which means you can convert machines without any downtime
• Wide Compatibility: It supports a range of source physical machines and third-party virtual machines, including Hyper-V and Amazon EC2 instances
• Centralized Management: VMware Converter provides a centralized management console that allows you to queue up and monitor multiple simultaneous conversions

We hope that helps answer the question.