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Five problems to watch for when running Linux VMs on Hyper-V

Windows Server 2012 R2 includes enhanced support for Linux VMs, but some problems remain.

Microsoft has clearly made an effort to enhance support for Linux virtual machines running under Hyper-V in the latest version of its Windows Server operating system. While it has always been possible to run Linux as the guest operating system on a Hyper-V VM, those VMs often faced limitations and lacked support for some features. Windows Server 2012 R2 added several new enhancements for Linux VMs that remove some of the limitations, including support for Hyper-V Dynamic Memory and live backup. However, feature support across different Linux distributions varies and some potential problems remain. Administrators should carefully evaluate whether it's a good idea to run Linux VMs on Hyper-V and -- if so -- prepare for these limitations. Here are five quick links that can help you understand the complications and how to address them.

Problems to expect when running RHEL 6.5 -- While Windows Server 2012 and 2012 R2 supports Red Hat Enterprise Linux, there are several caveats you should be aware of if your Linux VMs use RHEL 6.5 -- including the possibility that some features may be disabled by default.

Can't secure boot or use UEFI with a SUSE VM -- Generation 2 VMs support the Unified Extensible Firmware Interface (UEFI) rather than traditional legacy BIOS. However, some versions of SUSE Linux do not support UEFI firmware or secure boot functionality for Generation 2 VMs.

Requirements and potential "gotchas" with live backup -- Windows Server's live backup feature allows you to create a backup copy of a VM while it is running, but your system must first meet several requirements. Find out what you need and what could go wrong if you're running Oracle Linux VMs.

How NUMA architecture can cause problems -- Non-uniform memory access, or NUMA, is a computer design approach that segregates memory and can improve performance. However, there are known issues with the 2.6.x Linux kernels that could cause you problems.

Hyper-V bug that affects Linux VM networking -- New Hyper-V improvements smooth many of the troubles with using Linux VMs, including networking and backup features. However, there is a known Hyper-V bug that can cause a Linux VM to use a random value for the network name, which might lead to a loss of network connectivity. Learn what you can do to avoid the problem.

Next Steps

Microsoft Hyper-V administration guide

Windows Server 2012 R2 updates focus and cloud and security

Running windows as a VM on Linux with VMware Server

Dig Deeper on Microsoft Hyper-V management