This section describes how Acronis Backup supports new features introduced in Hyper-V 3.0. This version of Hyper-V appears in Windows Server 2012.
VHDX format
The VHDX format appeared in Hyper-V 3.0 as a new version of the virtual hard disk (VHD) format. The VHDX format supports a maximum disk size of 64 TB, compared with the maximum size of 2 TB for VHD. The VHDX format also supports disks with a physical and/or logical sector size of 4 KB.
Agent for Hyper-V can back up and recover virtual machines whose disks have the VHDX format. When recovering a virtual machine from a Hyper-V host of an earlier version to a Hyper-V 3.0 host, the agent converts the machine's disks to the VHDX format.
When recovering a virtual machine with VHDX disks to a Hyper-V host of an earlier version, the agent converts the disks to the VHD format. The agent tries to make the resulting disk meet the requirements of the VHD format. For example, if the source VHDX disk is greater than 2 TB, the agent attempts to reduce the resulting VHD disk size to 2 TB.
Dynamic Memory
Dynamic Memory adjusts the original amount of the virtual machine's memory depending on the machine's actual memory needs. Agent for Hyper-V can back up and recover virtual machines that use the Dynamic Memory feature. However, the agent does not save the Dynamic Memory settings for these machines.
When recovering a machine to a new virtual machine, the agent sets up the original amount of memory for it. The Dynamic Memory feature for the recovered machine will be turned off.
Private VLANs
Private virtual local area networks (private VLANs, PVLANs) enable you to isolate groups of virtual machines on a host as if each group were on a separate physical network. This feature of Hyper-V 3.0 is useful when hosting virtual machines of more than one organization, to prevent any communication between machines that belong to different organizations.
When backing up a Hyper-V 3.0 virtual machine, Agent for Hyper-V backs up the machine's PVLAN settings. The agent recovers these settings when recovering the machine to a new or existing machine on the same host.
When recovering the machine to a different host, the agent clears the PVLAN settings for the recovered machine.
Virtual Fibre Channel HBAs
Virtual Fibre Channel host bus adapters (HBAs) enable each virtual machine to access a Fibre Channel storage as if the machine had an individual Fibre Channel connection. For example, you can configure a virtual machine to access only a specific logical unit number (LUN) of a Storage Area Network (SAN), rather than all of the LUNs available to the Hyper-V host.
Although Agent for Hyper-V can back up virtual machines that have HBAs, it cannot back up the contents of the storage itself. If you have to back up this storage directly from the virtual machine, install Agent for Windows into the guest operating system.