Chapter 7
Failover Clustering and Migration Technologies
As previously discussed, when implementing virtualization, you consolidate your
operating systems onto fewer pieces of hardware, effectively putting your eggs in a
smaller number of baskets. It’s therefore important that those baskets are as secure as
possible and, in the event a basket breaks, there is another basket underneath to catch
the eggs that fall.
Failover Clustering provides resiliency for Windows services such as SQL, Exchange,
file, and print—and now for Hyper-V. By leveraging the failover cluster feature, Hyper-
V servers can share storage resources such as LUNs on a SAN or, with Windows Server
2016, local storage in each node through Storage Spaces Direct. More important,
however, clustering provides high availability from a node failure by moving virtual
machines to another node, plus it enables highly efficient migrations of virtual
machines between nodes in planned scenarios such as hardware maintenance.
Clustering also ensures that if a break occurs between nodes in a cluster, only one part
of that cluster will offer services, to avoid any chances of corruption. Windows Server
2012 introduced new types of mobility, both within a cluster and outside a cluster,
providing even more flexibility for Hyper-V environments, which has seen continued
investment in Windows Server 2012 R2 and Windows Server 2016.
In this chapter, you will learn to:
Understand the quorum model used in Windows Server 2012 and above.
Identify the types of mobility available with Hyper-V.
Understand the best way to patch a cluster with minimal impact to workloads.