Virtual machine configuration or disk files appear in binary format on ESXi host for VMs with RDM disks

Products

• VMware vCenter Server

Issue/Introduction

• Unable to register a virtual machine (VM) on an ESXi host.
• The VM appears in an "Invalid" or "Orphaned" state in vCenter Server inventory.
• Attempting to view the .vmx or .vmdk files via terminal (Putty/SSH) using command cat or less shows garbled binary data instead of plain text.

Environment

• VMware vSphere 8.x

Cause

The virtual machine configuration (.vmx) or descriptor (.vmdk) files have become corrupted or overwritten with binary data, often due to storage-level corruption.

Resolution

If these files are corrupted and unreadable, use one of the following methods to restore service.

Method 1: Restore from Backup

Consult your backup team to restore a valid, uncorrupted copy of the .vmx and .vmdk files. This is the preferred method to ensure all metadata is preserved.

Method 2: Rebuild the VM and Re-map Existing RDM LUNs

If no backups are available, follow these steps to rebuild the VM while preserving the data on RDM disks:

1. Remove the Invalid VM: Right-click the VM in the inventory and select Remove from Inventory.
2. Create a New VM: In the vSphere Client, create a new virtual machine with similar hardware specifications (CPU, Memory, Network) as the original.
3. Map RDM Disks:
   • During the "Customize Hardware" step, select Add New Device > RDM Disk.
   • Select the LUN that was previously attached to the corrupted VM.
   • Ensure the SCSI Controller ID matches the original configuration if the guest OS depends on it.
4. Reference Documentation: For detailed steps, see ADD an RDM disk