Information Technology Reference
In-Depth Information
The same goes for Network I/O Control (NIOC), which provides VMware administrators
with more granular controls over how VMs use network bandwidth provided by the physical
NICs. As the widespread adoption of 10 Gigabit Ethernet continues, Network I/O Control pro-
vides VMware administrators with a way to more reliably ensure that network bandwidth is
properly allocated to VMs based on priority and limits.
Profile-Driven Storage
With proi le-driven storage, vSphere administrators are able to use storage capabilities and VM
storage proi les to ensure that VMs are residing on storage that is able to provide the necessary
levels of capacity, performance, availability, and redundancy. Proi le-driven storage is built on
two key components:
◆
Storage capabilities, leveraging vSphere's storage awareness APIs
VM storage proi les
◆
Storage capabilities are either provided by the storage array itself (if the array is capable of
using vSphere's storage awareness APIs) and/or dei ned by a vSphere administrator. These stor-
age capabilities represent various attributes of the storage solution.
VM storage proi les dei ne the storage requirements for a VM and its virtual disks. You create
VM storage proi les by selecting the storage capabilities that must be present for the VM to run.
Datastores that have all the capabilities dei ned in the VM storage proi le are compliant with the
VM storage proi le and represent possible locations where the VM could be stored.
This functionality gives vSphere administrators much greater visibility into storage capabili-
ties and helps ensure that the appropriate functionality for each VM is indeed being provided
by the underlying storage.
Refer to Table 1.1 to i nd out which chapter discusses proi le-driven storage in more detail.
vSphere High Availability
In many cases, high availability—or the lack of high availability—is the key argument used
against virtualization. The most common form of this argument more or less sounds like this:
“Before virtualization, the failure of a physical server affected only one application or workload.
After virtualization, the failure of a physical server will affect many more applications or work-
loads running on that server at the same time. We can't put all our eggs in one basket!”
VMware addresses this concern with another feature present in ESXi clusters called vSphere
High Availability (HA). Once again, by nature of the naming conventions (clusters, high avail-
ability), many traditional Windows administrators will have preconceived notions about this
feature. Those notions, however, are incorrect in that vSphere HA does not function like a high-
availability coni guration in Windows. The vSphere HA feature provides an automated process
for restarting VMs that were running on an ESXi host at a time of server failure (or other quali-
fying infrastructure failure, as we'll describe in Chapter 7, “Ensuring High Availability and
Business Continuity”). Figure 1.3 depicts the VM migration that occurs when an ESXi host that
is part of an HA-enabled cluster experiences failure.
