machineType property

Full or partial URL of the machine type resource to use for this instance, in the format: zones/zone/machineTypes/machine-type.

This is provided by the client when the instance is created. For example, the following is a valid partial url to a predefined machine type: zones/us-central1-f/machineTypes/n1-standard-1 To create a custom machine type, provide a URL to a machine type in the following format, where CPUS is 1 or an even number up to 32 (2, 4, 6, ... 24, etc), and MEMORY is the total memory for this instance. Memory must be a multiple of 256 MB and must be supplied in MB (e.g. 5 GB of memory is 5120 MB): zones/zone/machineTypes/custom-CPUS-MEMORY For example: zones/us-central1-f/machineTypes/custom-4-5120 For a full list of restrictions, read the Specifications for custom machine types.