Virtual Machine (VM) with Hardware Version 21 fails to recognize or boot from attached ISO media

Products

• VMware vCenter Server

Issue/Introduction

When creating a virtual machine using Hardware Version 21 (vSphere 8.0), you may observe that the guest fails to recognize or boot from attached ISO media. Despite the ISO being correctly mapped to the virtual CD/DVD drive, the following symptoms may be observed:

• The EFI Boot Manager displays the SATA CDROM status as "No Media."
• The vmware.log contains entries such as:
  • Guest: Status upon boot failure: No Media
  • CDROM: initial physical CDROM state is 1 (sense)
• Attempting to switch the VM firmware from EFI to BIOS results in the error: "Operation failed! ACPI motherboard layout requires EFI."
• VMs created with hardware version 21

Cause

Virtual machines with hardware version 20 and EFI firmware are created with ACPI motherboard by default. The ACPI layout requires EFI firmware. Changing the firmware to BIOS is not supported in this case.

Resolution

To resolve this mismatch, ensure the recovery media architecture matches the virtual hardware requirements using one of the following methods:

Method 1: Rebuild the ISO for UEFI by updating the configuration on the source server to support UEFI. This ensures the resulting ISO includes the necessary bootloaders and directory structure required for EFI firmware recognition.

Method 2: Use a bios-compatiable virtual machine If rebuilding the ISO is not an option, create a new virtual machine using an older hardware version that supports Legacy BIOS:

1. Create a new virtual machine (Hardware Version 21 cannot be downgraded to BIOS once the EFI layout is set).
2. Select Hardware Version 19 or earlier during the creation wizard.
3. In the VM Options, select BIOS as the firmware type.
4. Attach the CD/DVD drive and ensure the boot order is set to check the optical drive first.

Additional Information

Reference KB:

Restrictions for changing the firmware/BIOS of certain Virtual Machines