---
title: machineIdentifier
framework: virtualization
role: symbol
role_heading: Instance Property
path: virtualization/vzmacplatformconfiguration/machineidentifier
---

# machineIdentifier

The Mac machine identifier.

## Declaration

```swift
@NSCopying var machineIdentifier: VZMacMachineIdentifier { get set }
```

## Discussion

Discussion This value uniquely identifies an instance of a VM. Running two VMs concurrently with the same identifier results in undefined behavior in the guest operating system.

## See Also

### Getting platform properties

- [auxiliaryStorage](virtualization/vzmacplatformconfiguration/auxiliarystorage.md)
- [hardwareModel](virtualization/vzmacplatformconfiguration/hardwaremodel.md)