Hardware generations

Compute Cloud VMs are a combination of virtualized hardware and software deployed on it. A virtual machine's virtualized hardware is defined by the platform configuration, vCPU performance level, and virtualized hardware generation.

Each generation has its own set of specifications determining the following VM features:

• PCI bus topology.
• Maximum possible number of connected disk devices and network interfaces.

Hardware generation specificationsHardware generation specifications

¹ For VMs without GPUs hosted on two NUMA nodes of a physical server.

Assigning a generation to a VMAssigning a generation to a VM

The hardware generation features must be supported by the VM's operating system. The OS boots from a boot disk, which in turn is created from an image or snapshot. Therefore, the hardware generation is assigned to each disk, image, and snapshot and registered in the VM's parameters when creating the VM.

You can change the hardware generation assigned to a disk, image, or snapshot when recreating it from an existing disk, image, or snapshot. If you do not specify a hardware generation when creating a disk, image, or snapshot, it will get the same generation assigned as the original disk, image, or snapshot. For more information, see these guides:

• Creating a disk
• Disk snapshots
• Creating an image

If your VM requires features that are not available for the current generation, such as connecting more disk devices and network interfaces or increasing boot speed, recreate your VM in a new configuration. Do it by creating a snapshot or image of your VM's boot disk with the right generation assigned, and then create a new VM with a new hardware configuration from the resulting snapshot or image.