Specifications
64 CHAPTER 4 High Availability and Virtualization Enhancements
■
Windows Server 2008 R2 Hyper-V The Hyper-V virtualization technology im-
provements in Windows Server 2008 R2 were the most sought-after and anticipated
enhancements for Windows Server 2008 R2. It is now possible to virtualize heavy SQL
Server workloads because Windows Server 2008 R2 scales far beyond its predecessors.
In addition, database administrators can achieve increased virtualization availability by
leveraging new technologies, such as Clustered Shared Volumes (CSV) and Live Migra-
tion, both of which are included in Windows Server 2008 R2. Guest clustering with SQL
Server 2008 R2 in Windows Server 2008 R2 Hyper-V is also supported.
■
Live Migration and Hyper-V By leveraging Live Migration and CSV—two new
technologies included with Hyper-V and failover clustering on Windows Server 2008
R2—it is possible to move virtual machines between Hyper-V hosts within a failover
cluster without downtime. It is worth noting that CSV and Live Migration are indepen-
dent technologies; CSV is not required for Live Migration.
■
Cluster Shared Volumes (CSV) CSV enables multiple Windows servers running
Hyper-V to access Storage Area Network (SAN) storage using a single consistent
namespace for all volumes on all hosts. This provides the foundation for Live Migration
and allows for the movement of virtual machines between Hyper-V hosts.
■
Dynamic virtual machine (VM) storage It is possible to add or remove virtual
hard disk (VHD) les and pass-through disks while a VM is running. Support for hot
plugging and hot removal of storage is based on Hyper-V. This is very handy when you
are working with dynamic SQL Server 2008 R2 storage workloads, which are continu-
ously evolving.
■
Second Level Address Translation (SLAT) Enhanced processor support and
memory management can be achieved with SLAT, which is a new feature supported
with Hyper-V in Windows Server 2008 R2. SLAT leverages Intel Virtualization Technol-
ogy (VT) Extended Page Tables (EPT) and AMD-V Rapid Virtualization Indexing (RVI)
technology in an effort to reduce the overhead incurred during mapping of a guest
virtual address to a physical address for virtual machines. This signicantly reduces
hypervisor CPU time and saves memory for each VM, allowing the physical computer
to do more work while utilizing fewer system resources.
Failover Clustering with Windows Server 2008 R2
If you’re unfamiliar with failover clustering, don't stop reading to run out and purchase a book
on the topic—this section begins with an overview of failover clustering. It may surprise some
readers to know that SQL Server failover clustering has been available since Microsoft SQL
Server 7.0. Back in those days, failover clustering proved to be quite a challenge to set up. It
was necessary to install multiple Microsoft products to form the Microsoft cluster environment,