vmdk size is differently displayed from vSphere Client and PowerCLI

Products

• VMware vCenter Server

Issue/Introduction

This articles explains how vSphere Client and PowerCLI displays vmdk size.

Environment

VMware vCenter Server

Resolution

When configuring vmdk from vSphere Client, it tries to display vmdk size in user-friendly units to improve readability, but precise fractional values may be truncated during this process.

For example, if you configure 1025MB vmdk from vSphere Client, save and close the wizard, and then open the [Edit Settings...], you'll see the disk size as 1.001 GB. It seems to indicate the disk size is 1025.024 MB (1024 * 1.001), but is 1025MB in reality.

Because of this behavior disk size fetched by PowerCLI could be different from the size displayed from vSphere Client [Edit Settings...] wizard, so please recognize the difference. If you need precise value of vmdk size, use values from PowerCLI.