Chapter 7: Failover Clustering and Migration
Technologies
Understand the quorum model used in Windows Server 2012 R12 and
above. Windows Server 2012 R2 removed all of the previous models that were based
on the way votes were allocated and the type of quorum resource. In Windows Server
2012 R2, each node has a vote and a witness is always configured, but it’s used only
when required. Windows Server 2012 introduced dynamic quorum, which helps
ensure that clusters stay running for as long as possible as nodes’ votes are removed
from quorum because the nodes are unavailable. Windows Server 2012 R2 added
dynamic witness to change the vote of the witness resource based on whether there
are an odd or even number of nodes in the cluster.
Identify the types of mobility available with Hyper-V. Mobility focuses on the
ability to move virtual machines between Hyper-V hosts. Virtual machines within a
cluster can be live-migrated between any node efficiently, since all nodes have access
to the same storage, allowing only the memory and state to be copied between the
nodes. Windows Server 2012 introduced the ability to move the storage of a virtual
machine with no downtime, which when combined with Live Migration enables a
Shared Nothing Live Migration capability that means a virtual machine can be moved
between any two Hyper-V hosts without the need for shared storage or a cluster, with
no downtime to the virtual machine.
Shared Nothing Live Migration does not remove the need for Failover Clustering but
provides the maximum flexibility possible, enabling virtual machines to be moved
between stand-alone hosts, between clusters, and between stand-alone hosts and
clusters.
Master It Why is constrained delegation needed when using Shared Nothing Live
Migration with remote management?
Solution Windows does not allow a server that has been given a credential to pass
that credential on to another server. Constrained delegation enables credentials to
be passed from a server to another specific server for defined purposes. This
enables management to be performed remotely, including migration initialization.Understand the best way to patch a cluster with minimal impact to
workloads. All virtual machines in a cluster can run on any of the member nodes.
That means before you patch and reboot a node, all virtual machines should be moved
to other nodes by using Live Migration, which removes any impact on the availability
of the virtual machines. While the migration of virtual machines between nodes can
be performed manually, Windows Server 2012 Failover Clustering provides Cluster-
Aware Updating, giving you a single-click ability to patch the entire cluster without
any impact to virtual machines’ availability. For pre-Windows Server 2012 clusters,
SCVMM 2012 also provides an automated patching capability. Configuration Manager