On VMware platform products, .vmx is a text file (usually located in the same directory as virtual disk files) specifying virtual machine configuration. The Virtual Machine eXecutable (VMX) process is the user-space component (or “world”) of a virtual machine. The virtual disk library connects to virtual machine storage through the VMX process.

When specifying connection parameters (see Data Structures in Virtual Disk API) the preferred syntax for vmxSpec is as follows:

  • Managed object reference of the virtual machine, an opaque object that you obtain programmatically using the PropertyCollector managed object:
    moRef=<moref-of-vm>

    The moRef of a virtual machine or disk snapshot on an ESXi host is likely different than the moRef of the same virtual machine or disk snapshot as managed by vCenter Server. Here are two example moRef specifications, one for ESXi and one for vCenter Server, both referring to the same snapshot:

    moref=153
    moref=271