vSphere Infrastructure and Hypervisor Components
This is module 2, vSphere Infrastructure and Hypervisor Components.
These are the topics that will be covered in this module.
Student Study Guide – VTSP 5.5
Module 2 Objectives
At the end of this module you will be able to:
Identify the key features of vSphere 5.5, describing the key capabilities and identifying the key value propositions of each one.
Identify any license level restrictions for each feature.
VTSP 5.5 - Student Study Guide
vSphere Distributed Services – vSphere vMotion
Let's discuss Distributed Services. vMotion, Storage vMotion, VMware HA , FT, DRS, DPM and Replication are distributed services that enable efficient and automated resource management and high availability for virtual machines.
vMotion enables the migration of live virtual machines from one physical server to another without service interruption. This live migration capability allows virtual machines to move from a heavily loaded server to a lightly loaded one. vMotion is discussed in Course 3.
Student Study Guide – VTSP 5.5
vSphere Distributed Services – vSphere Storage vMotion
Storage vMotion enables live migration of a virtual machine's storage to a new datastore with no downtime. Extending the vMotion technology to storage helps the vSphere administrator to leverage storage tiering, perform tuning and balancing, and control capacity with no application downtime.
Storage vMotion copies disk blocks between source and destination and replaces the need for the iterative pre-copy phase. This was used in the Changed Block Tracking (CBT) method in earlier versions of vSphere. With I/O mirroring, a single-pass copy of the disk blocks from the source to the destination is performed. I/O mirroring ensures that any newly changed blocks in the source are mirrored at the destination. There is also a block-level bitmap that identifies hot and cold blocks of the disk, or whether the data in a given block is already mirrored in the destination disk.
Storage vMotion is discussed in Course 3.
VTSP 5.5 - Student Study Guide
vSphere Distributed Services – vSphere High Availability
vSphere High Availability (HA) provides easy-to-use, cost effective high availability for applications running in virtual machines.
In the event of physical server failure, the affected virtual machines are restarted on other production servers which have spare capacity.
In the case of operating system failure, vSphere HA restarts the affected virtual machine on the same physical server.
Student Study Guide – VTSP 5.5
vSphere Distributed Services – vSphere High Availability
vSphere App HA is a plug-in to the vSphere Web Client. This plug-in allows you to define high availability for the applications that are running on the virtual machines in your environment, reducing application downtime.
vSphere HA and App HA are discussed in Course 2.
VTSP 5.5 - Student Study Guide
vSphere Distributed Services – vSphere Fault Tolerance
Fault Tolerance (FT) provides continuous availability for applications in the event of server failures by creating a live shadow instance of a virtual machine that is in virtual lockstep with the primary instance.
The Secondary virtual machine can take over execution at any point without service interruption.
By allowing instantaneous failover between the two instances in the event of hardware failure, FT eliminates even the smallest chance of data loss or disruption.
Fault Tolerance is discussed in Course 2.
Student Study Guide – VTSP 5.5
vSphere Distributed Services – vSphere DRS
Distributed Resource Scheduler (DRS) helps you manage a cluster of physical hosts as a single compute resource by balancing CPU and memory workload across the physical hosts.
DRS uses vMotion to migrate virtual machines to other hosts as necessary.
When you add a new physical server to a cluster, DRS enables virtual machines to immediately take advantage of the new resources because it distributes the running virtual machines.
DRS is discussed in Course 2.
VTSP 5.5 - Student Study Guide
vSphere Distributed Services – vSphere Storage DRS
Storage DRS (SDRS) aggregates storage resources of several datastores in to a single datastore cluster to simplify storage management at scale with vSphere Storage DRS.
During virtual machine provisioning Storage DRS provides intelligent virtual machine placement based on the IO load and available storage capacity of the datastores.
Storage DRS performs ongoing load balancing between datastores to ensure space and I/O bottlenecks are avoided as per pre-defined rules that reflect business needs and changing priorities.
Storage DRS is discussed in Course 5.
Student Study Guide – VTSP 5.5
vSphere Distributed Services – vSphere DPM
Distributed Power Management (DPM) continuously optimizes power consumption in the data center.
When virtual machines in a DRS cluster need fewer resources, such as at night and on weekends, DPM consolidates workloads onto fewer servers and powers off the rest to reduce power consumption.
When virtual machine resource requirements increase, DPM brings powered-down hosts back online to ensure service levels are met.
DPM is discussed in Course 2.
VTSP 5.5 - Student Study Guide
vSphere Replication
vSphere Replication replicates powered-on virtual machines over the network from one vSphere host to another without needing storage array-based native replication.
vSphere Replication reduces bandwidth needs, eliminates storage lock-in, and allows you to build flexible disaster recovery configurations.
This proprietary replication engine copies only changed blocks to the recovery site, ensuring both lower bandwidth utilization and more aggressive recovery point objectives compared with manual full system copies of virtual machines.
Replication is discussed in Course 3.
Student Study Guide – VTSP 5.5
vSphere Networking – Network Architecture
The virtual environment provides similar networking elements as the physical world, such as virtual network interface cards, vSphere Distributed Switches (VDS), distributed port groups, vSphere Standard Switches (VSS), and port groups.
Like a physical machine, each virtual machine has its own virtual NIC called a vNIC.
The operating system and applications talk to the vNIC through a standard device driver or a VMware optimized device driver just as though the vNIC is a physical NIC.
To the outside world, the vNIC has its own MAC address and one or more IP addresses and responds to the standard Ethernet protocol exactly as a physical NIC would. In fact, an outside agent can determine that it is communicating with a virtual machine only if it checks the 6-byte vendor identifier in the MAC address.
A virtual switch, or vSwitch, works like a layer-2 physical switch. With VSS, each host maintains its own virtual switch configuration while in a VDS, a single virtual switch configuration spans many hosts.
Physical Ethernet adapters connected to physical switches provide an uplink for vSwitches.
VTSP 5.5 - Student Study Guide
vSphere Networking – vSphere Standard Switches
vSphere Standard Switches allow virtual machines on the same vSphere host to communicate with each other using the same protocols used with physical switches.
The virtual switch emulates a traditional physical Ethernet network switch to the extent that it forwards frames at the data link layer.
Standard switches are discussed in course 4.
Student Study Guide – VTSP 5.5
vSphere Networking – vSphere Distributed Switches
The vSphere Distributed Switch (VDS) simplifies virtual machine networking by enabling you to set up virtual machine access switching for your entire data center from a
centralized interface.
VDS provides simplified virtual machine network configuration, enhanced network monitoring and troubleshooting capabilities and support for advanced vSphere networking features.
Distributed Switches are discussed in course 4.
VTSP 5.5 - Student Study Guide
Network I/O Control: An Overview
Network I/O control enables the convergence of diverse workloads on a single
networking pipe. It provides control to the administrator to ensure predictable network performance when multiple traffic types are flowing in the same pipe.
Network I/O control provides sufficient controls to the vSphere administrator in the form of limits, and shares parameters to enable and ensure predictable network performance when multiple traffic types contend for the same physical network resources.
Network I/O Control is discussed in Course 4.
Student Study Guide – VTSP 5.5
vSphere Storage Architecture
The VMware vSphere Storage Architecture consists of layers of abstraction that hide and manage the complexity and differences among physical storage subsystems.
To the applications and guest operating systems inside each virtual machine, the storage subsystem appears as a virtual SCSI controller connected to one or more virtual SCSI disks.
These controllers are the only types of SCSI controllers that a virtual machine can see and access.
The virtual SCSI disks are provisioned from datastore elements in the data center.
The guest virtual machine is not exposed to Fibre Channel SAN, iSCSI SAN, direct attached storage, and NAS.
Each datastore is a physical VMFS volume on a storage device. NAS datastores are an NFS volume with VMFS characteristics.
Datastores can span multiple physical storage subsystems. VMFS also supports raw device mapping (RDM). RDM provides a mechanism for a virtual machine to have direct access to a LUN on the physical storage subsystem (Fibre Channel or iSCSI only).
vSphere Storage Architecture is discussed in Course 5.
VTSP 5.5 - Student Study Guide
Virtual Machine File System
Virtual Machine File System (VMFS) is a high-performance cluster file system that provides storage virtualization optimized for virtual machines.
VMFS is the default storage management interface for block based disk storage (Local and SAN attached).
VMFS allows multiple instances of VMware vSphere servers to access shared virtual machine storage concurrently.
VMFS is discussed in Course 5.
Student Study Guide – VTSP 5.5
Virtual Disks
When you create a virtual machine, a certain amount of storage space on a datastore is provisioned, or allocated, to the virtual disk files. Each of the three vSphere hosts has two virtual machines running on it.
The lines connecting them to the disk icons of the virtual machine disks (VMDKs) are logical representations of their allocation from the larger VMFS volume, which is made up of one large logical unit number (LUN).
A virtual machine detects the VMDK as a local SCSI target.
The virtual disks are really just files on the VMFS volume, shown in the illustration as a dashed oval.
Virtual Disks are discussed in Course 3 and Course 5.
VTSP 5.5 - Student Study Guide
Storage I/O Control
vSphere Storage I/O Control (SIOC) is used to provide I/O prioritization of virtual machines running on a group of VMware vSphere hosts that have access to a shared storage pool.
It extends the familiar constructs of shares and limits, which exist for CPU and memory, to address storage utilization through a dynamic allocation of I/O capacity across a cluster of vSphere hosts.
Configure rules and policies to specify the business priority of each virtual machine.
When I/O congestion is detected, Storage I/O Control dynamically allocates the available I/O resources to virtual machines according to your rules, improving service levels for critical applications and allowing you to virtualize more types of workloads, including I/O-intensive applications.
SIOC is discussed in Course 5.
Student Study Guide – VTSP 5.5
vSphere Hypervisor 5.5 Architecture
VMkernel is a POSIX-like OS developed by VMware and provides certain functionalities similar to that found in other OSs, such as process creation and control, signals, file system, and process threads. It is designed specifically to support running multiple virtual machines and provides core functionalities such as resource scheduling, I/O stacks and device drivers.
The key component of each ESXi host is a process called VMM. One VMM runs in the VMkernel for each powered on virtual machine. When a virtual machine starts running, the control transfers to the VMM, which in turn begins executing instructions from the virtual machine. The VMkernel sets the system state so that the VMM runs directly on the hardware.
The devices of a virtual machine are a collection of virtual hardware that includes the devices shown. The ESXi host provides a base x86 platform and you choose devices to install on that platform. The base virtual machine provides everything needed for the system compliance with x86 standards from the motherboard up.
VMware virtual machines contain a standard set of hardware no matter what platform you are running. Virtual device drivers allow portability without having to reconfigure the OS of each virtual machine.
VMware Tools is a suite of utilities that enhances the performance of the virtual
VTSP 5.5 - Student Study Guide
VMware Tools in the guest OS is vital. Although the guest OS can run without VMware Tools, you lose important functionality and convenience.
ESXi uses five memory management mechanisms-page sharing, ballooning, memory compression, swap to host cache, and regular swapping-to dynamically reduce the amount of physical memory required for each virtual machine.
All of these topics are discussed in Course 3.
Student Study Guide – VTSP 5.5
Licensing Requirements for vSphere features
From this table you can see the types of licenses which are required by each of the features discussed. Take a few moments to take in this table.
VTSP 5.5 - Student Study Guide
Module Summary
This concludes module 2, vSphere Infrastructure and Hypervisor Components.
Now that you have completed this module, you should be able to:
Identify the key features of vSphere 5.5 describing the key capabilities and identifying the key value propositions of each one.
Identify any license level restrictions for each feature.
Student Study Guide – VTSP 5.5