Generation 2 VMs use synthetic drivers and software-based devices instead, and provide
advantages that include the following:
- UEFI boot Instead of using the traditional BIOS, Generation 2 VMs support Secure Boot, using the Universal Extensible Firmware Interface (UEFI), which requires a system to boot from digitally signed drivers and enables them to boot from drives larger than 2 TB, with GUID partition tables. UEFI is fully emulated in VMs, regardless of the firmware in the physical host server.
- SCSI disks Generation 2 VMs omit the IDE disk controller used by Generation 1 VMs to boot the system and use a high-performance virtual SCSI controller for all disks, enabling the VMs to boot from VHDX files, support up to 64 devices per controller, and perform hot disk adds and removes.
- PXE boot The native virtual network adapter in Generation 2 VMs supports booting from a network server using the Preboot Execution Environment (PXE). Generation 1 VMs require you to use the legacy network adapter to support PXE booting.
- SCSI boot Generation 2 VMs can boot from a SCSI device, which Generation 1 VMs cannot. Generation 2 VMs have no IDE or floppy controller support, and therefore cannot boot from these devices.
- Boot volume size Generation 2 VMs can boot from a volume up to 64 TB in size, while Generation 1 boot volumes are limited to 2 TB.
- VHDX boot volume resizing In a Generation 2 VM, you can expand or reduce a VHDX boot volume while the VM is running.
- Software-based peripherals The keyboard, mouse, and videos drivers in a Generation 2 VM are software-based, not emulated, so they are less resource-intensive and provide a more secure environment.
- Hot network adapters In Generation 2 VMs, you can add and remove virtual network adapters while the VM is running.
- Enhanced Session Mode Generation 2 VMs support Enhanced Session Mode, which provides Hyper-V Manager and VMConnect connections to the VM with additional capabilities, such as audio, clipboard support, printer access, and USB devices.
- Shielded virtual machines Generation 2 VMs can be shielded, so that the disk and the system state are encrypted and accessible only by authorized administrators.
- Storage Spaces Direct Generation 2 VMs running Windows Server 2016 Datacenter Edition support Storage Spaces Direct, which can provide a high-performance, faulttolerant storage solution using local drives