The initial version of Hyper-V only supported one minimal feature for Linux virtual machines (VM) through the installation of an additional component called Linux Integration Services (LIS). But recently, Microsoft has been working with providers to add new features without having to install SIL in newer Linux distributions.
One of the most awaited is the Dynamic Memory. The addition and removal of memory are now fully compatible with virtual machines running on a Windows Server Linux 2012 R2 Hyper-V host. It is important to note that this function is only available for 64-bit Linux distros and in some of them it is necessary to enable support, for example in CentOS and Red Hat Linux distributions.
Another of the innovations is VMs live backup. Now, backup of the Linux VMs running on Windows Server Linux 2012 R2 Hyper-V host can be performed without downtime using Hyper-V backup tools, like Windows Server Backup.
The support of second generation virtual machines is also a new feature. Starting with Windows Server 2012 R2 you can install new Linux distributions, such as Ubuntu 14.10, CentOS, Red Hat Enterprise 7.0 and SUSE SLES 12 as second generation VMs.
In addition, now online backup of Linux virtual machines running on Hyper-V Windows Server hosts 2012 R2 can be enabled using Windows Azure Online Backup and System Center Data Protection Manager.
It should be also pointed out that it is possible to resize VHDX files attached to an Linux VM without downtime. It's a very welcome feature, since it avoids complex change management processes and helps to increase the storage of Linux critical workloads without downtime.
Finally, an integration services component called Guest Services has been incorporated. When enabed, it allows to copy files from the host to Linux VMs. At the moment it is supported only by CentOS, Red Hat 7.0 and 6.6, SUSE SLES 12 and Ubuntu 14.10 and 14.04.
For more information, read the full article in English