This is a follow up to the previous post for Server 2008 R2 (http://thebitsthatbyte.com/know-your-limits-capacity-planning-for-hyper-v-virtual-machines/) and provides limits for Virtual Machines running within Hyper-V on Server 2012.
You will notice that the differences are quite stunning, especially surrounding the amount of Virtual Processors, Memory, and Hard Disk Capacity (if using VHDX format). Full details can be found on the Microsoft page here: http://technet.microsoft.com/en-us/library/jj680093.aspx
| Component | Maximum | Notes |
|---|---|---|
| Virtual processors | 64 | The number of virtual processors supported by a guest operating system might be lower. For more information, see the Hyper-V Overview. |
| Memory | 1 TB | Review the requirements for the specific operating system to determine the minimum and recommended amounts. |
| Virtual hard disk capacity | 64 TB supported by the VHDX format introduced in Windows Server 2012 and Windows® 8; 2040 GB supported by the VHD format. | Each virtual hard disk is stored on physical media as either a .vhdx or a .vhd file, depending on the format used by the virtual hard disk. |
| Virtual IDE disks | 4 | The startup disk (sometimes referred to as the boot disk) must be attached to one of the IDE devices. The startup disk can be either a virtual hard disk or a physical disk attached directly to a virtual machine. |
| Virtual SCSI controllers | 4 | Use of virtual SCSI devices requires integration services to be installed in the guest operating system. For a list of the guest operating systems for which integration services are available, see the Hyper-V Overview. |
| Virtual SCSI disks | 256 | Each SCSI controller supports up to 64 disks, which means that each virtual machine can be configured with as many as 256 virtual SCSI disks. (4 controllers x 64 disks per controller) |
| Virtual Fibre Channel adapters | 4 | As a best practice, we recommended that you connect each virtual Fibre Channel Adapter to a different virtual SAN. |
| Size of physical disks attached directly to a virtual machine | Varies | Maximum size is determined by the guest operating system. |
| Snapshots | 50 | The actual number may be lower, depending on the available storage. Each snapshot is stored as an .avhd file that consumes physical storage. |
| Virtual network adapters | 12 |
|
| Virtual floppy devices | 1 virtual floppy drive | None. |
| Serial (COM) ports | 2 | None. |