VSICM6 m09 HighAvailabilityandFT

vSphere HA and vSphere Fault Tolerance
Module 9

© 2015 VMware Inc. All rights reserved.


You Are Here

9.

7.

Virtual Machine Management

10. Software-Defined Data Center

8.

Resource Management and Monitoring

11.

9.

vSphere HA and vSphere Fault Tolerance

Course Introduction

Creating Virtual Machines

12. vCenter Server

10. Host Scalability

13. Configuring and Managing Virtual Networks

11.

14. Configuring and Managing Virtual Storage

12. Installing vSphere Components

vSphere Update Manager and Host Maintenance

VMware vSphere: Install, Configure, Manage
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Importance
Most organizations rely on computer-based services like email, databases, and Web-based applications. The failure of any of
these services can mean lost productivity and revenue.
Configuring highly available, computer-based services is extremely important for an organization to remain competitive in
contemporary business environments.

VMware vSphere: Install, Configure, Manage
© 2015 VMware Inc. All rights reserved.

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Module Lessons
Lesson 1:

Introduction to vSphere HA

Lesson 2:

vSphere HA Architecture

Lesson 3:

Configuring vSphere HA

Lesson 4:

Introduction to vSphere Fault Tolerance

Lesson 5:

vSphere Replication and vSphere Data Protection

VMware vSphere: Install, Configure, Manage
© 2015 VMware Inc. All rights reserved.

9-4


Lesson 1:
Introduction to vSphere HA

9-5
© 2015 VMware Inc. All rights reserved.


Learner Objectives
By the end of this lesson, you should be able to meet the following objectives:

•

Describe the options that you can configure to make your VMware vSpheređ environment highly available

ã

Discuss the response of VMware vSphere® High Availability when a VMware ESXi™ host, a virtual machine, or an application fails

VMware vSphere: Install, Configure, Manage
© 2015 VMware Inc. All rights reserved.

9-6


Protection at Every Level
vSphere makes it possible to reduce planned downtime, prevent unplanned downtime, and recover
rapidly from outages.

VM
vSphere HA and vSphere Fault Tolerance

VM

vSphere Storage

vSphere 6

VM

vMotion

Site Recovery Manager

vSphere vMotion, vSphere DRS

NIC Teaming, Storage
Multipathing

VM

FS
VM

FS

vSphere Replication, Third-Party
Backup Solutions, vSphere Data Protection

Component

Server

Storage

Data

Site

VMware vSphere: Install, Configure, Manage
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9-7


vCenter Server Availability: Recommendations

Make VMware vCenter Server™ and the components that it relies on highly available.
vCenter Server relies on these major components:

•

vCenter Server database:

–

•

Create a cluster for the database.

Authentication identity source:

–

For example, VMware Center™ Single Sign-On™ and Active Directory.

–

Set up with multiple redundant servers.

Methods for making vCenter Server available:

•

Use vSphere HA to protect the vCenter Server virtual machine.

VMware vSphere: Install, Configure, Manage
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9-8


About vSphere HA
vSphere HA uses multiple ESXi hosts configured as a cluster to provide rapid recovery from outages and cost-effective high
availability for applications running in virtual machines.

Protects against

Protects against datastore

server failures

accessibility failures

Protects against application
failures

Protects virtual machines
against network isolation

VMware vSphere: Install, Configure, Manage
© 2015 VMware Inc. All rights reserved.

9-9


vSphere HA Scenarios: ESXi Host Failure

Virtual
Virtual Machine
Machine A
A

Virtual
Virtual Machine
Machine B
B

Virtual
Virtual Machine
Machine A
A

Virtual

Virtual Machine
Machine C
C

Virtual
Virtual Machine
Machine E
E

Virtual
Virtual Machine
Machine B
B

Virtual
Virtual Machine
Machine D
D

Virtual
Virtual Machine
Machine F
F

When a host fails, vSphere HA

ESXi Host

ESXi Host

vCenter Server

restarts the affected virtual machines
on other hosts.

ESXi Host

= vSphere HA Cluster

VMware vSphere: Install, Configure, Manage
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9-10


vSphere HA Scenarios: Guest Operating System Failure

Virtual Machine A
VMware
VMware Tools
Tools

Virtual Machine C
VMware
VMware Tools
Tools

Virtual Machine B

Virtual Machine D

VMware
VMware Tools
Tools

VMware
VMware Tools
Tools

Virtual Machine E
VMware
VMware Tools
Tools

Virtual Machine F
VMware
VMware Tools
Tools

When a virtual machine stops
sending heartbeats or the virtual
machine process crashes (vmx),
vSphere HA resets the virtual
machine.

ESXi Host

ESXi Host

vCenter Server

ESXi Host

= vSphere HA Cluster

VMware vSphere: Install, Configure, Manage
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9-11


vSphere HA Scenarios: Application Failure

Application
Application

Application
Application

Virtual
Virtual Machine
Machine A
A

Virtual
Virtual Machine
Machine C
C

Virtual
Virtual Machine

Machine E
E

Application
Application

Application
Application

Application
Application

Virtual
Virtual Machine
Machine B
B

Virtual
Virtual Machine
Machine D
D

Virtual
Virtual Machine
Machine F
F

Application
Application

When an application fails, vSphere HA
restarts the affected virtual machine on
the same host.
Requires installation of VMware
Tools™.

ESXi Host

ESXi Host

vCenter Server

ESXi Host

= vSphere HA Cluster

VMware vSphere: Install, Configure, Manage
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9-12


Importance of Redundant Heartbeat Networks

In a vSphere HA cluster, heartbeats have these characteristics:

•

Heartbeats are sent between the master host and the slave hosts.

•

They are used to determine whether a master host or slave host has failed.

•

They are sent over a heartbeat network.

Redundant heartbeat networks ensure reliable failure detection.
Heartbeat network implementation:

•

Implemented by using a VMkernel port marked for management.

VMware vSphere: Install, Configure, Manage
© 2015 VMware Inc. All rights reserved.

9-13


Redundancy Using NIC Teaming

You can use NIC teaming to create a redundant heartbeat network on ESXi hosts.
Ports or port groups used must be VMkernel ports.

NIC Teaming on an ESXi Host

VMware vSphere: Install, Configure, Manage
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9-14


Redundancy Using Additional Networks

You can also create redundancy by configuring more heartbeat networks: On each ESXi host, create a second VMkernel
port on a separate virtual switch with its own physical adapter.

VMware vSphere: Install, Configure, Manage
© 2015 VMware Inc. All rights reserved.

9-15


Review of Learner Objectives
You should be able to meet the following objectives:

•

Describe the options that you can configure to make your VMware vSpheređ environment highly available

ã

Discuss the response of VMware vSphere® High Availability when a VMware ESXi™ host, a virtual machine, or an application fails

VMware vSphere: Install, Configure, Manage
© 2015 VMware Inc. All rights reserved.

9-16

Lesson 2:
vSphere HA Architecture

9-17
© 2015 VMware Inc. All rights reserved.


Learner Objectives
By the end of this lesson, you should be able to meet the following objectives:

•

Describe the heartbeat mechanisms used by vSphere HA

•

Identify and discuss other failure scenarios

•

Recognize vSphere HA design considerations

VMware vSphere: Install, Configure, Manage
© 2015 VMware Inc. All rights reserved.

9-18

vSphere HA Architecture: Agent Communication

FDM
FDM

vpxa
vpxa

Datastore

Datastore

Datastore

FDM
FDM

FDM
FDM

hostd
hostd

ESXi Host (Slave)
(Slave)

To configure high availability, ESXi hosts are
grouped into an object called a cluster.

hostd

hostd

vpxa
vpxa

ESXi Host (Slave)
(Slave)

vpxd
vpxd

vpxa
vpxa

hostd
hostd

ESXi Host (Master)
(Master)

vCenter Server
= Management Network

VMware vSphere: Install, Configure, Manage
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9-19


vSphere HA Architecture: Network Heartbeats

VMFS

VMFS

NAS/NFS

Virtual
Virtual Machine
Machine A
A

Virtual
Virtual Machine
Machine C
C

Virtual
Virtual Machine
Machine E
E

Virtual
Virtual Machine
Machine B
B

Virtual
Virtual Machine
Machine D
D

Virtual
Virtual Machine
Machine F
F

Slave
Slave Host
Host

Slave Host

Master Host

The master host sends periodic heartbeats to the slave
hosts so that the slave hosts know that the master host
is alive.
vCenter Server
Management Network 1
Management Network 2

VMware vSphere: Install, Configure, Manage
© 2015 VMware Inc. All rights reserved.

9-20


vSphere HA Architecture: Datastore Heartbeats

VMFS

VMFS

NAS/NFS

Virtual
Virtual Machine
Machine A
A

Virtual
Virtual Machine
Machine C
C

Virtual
Virtual Machine
Machine E
E

Virtual
Virtual Machine
Machine B
B

Virtual
Virtual Machine
Machine D
D

Virtual
Virtual Machine
Machine F
F

Slave Host

Master Host

Datastores are used as a backup communication
channel to detect virtual machine and host
heartbeats.

Slave
Slave Host
Host
Cluster Edit Settings Window

vCenter Server
Management Network 1
Management Network 2

VMware vSphere: Install, Configure, Manage
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9-21


Additional vSphere HA Failure Scenarios

•

Slave host failure

•

Master host failure

•

Host isolation

•

Virtual machine storage failure:

–

•

Virtual Machine Component Protection

•

All Paths Down

•

Permanent Device Loss

Network failures and isolation

VMware vSphere: Install, Configure, Manage
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9-22


Failed Slave Host
When a slave host does not respond to the network heartbeat issued by the master host, the master vSphere HA agent tries
to identify the cause.
NAS/NFS

VMFS

(Lock File)

(Heartbeat Region)
File
File Locks
Locks

File
File Locks
Locks

Virtual
Virtual Machine
Machine A
A

Virtual
Virtual Machine
Machine C
C

Virtual
Virtual Machine
Machine E
E

Virtual
Virtual Machine
Machine B
B

Virtual
Virtual Machine
Machine D
D

Virtual
Virtual Machine
Machine F
F

Failed
Failed Slave
Slave Host
Host

vCenter Server

Master
Master Host
Host

Slave
Slave Host
Host

Primary Heartbeat Network
Alternate Heartbeat Network

VMware vSphere: Install, Configure, Manage
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9-23


Failed Master Host
When the master host is placed in maintenance mode or crashes, the slave hosts detect that the master host is no longer
issuing heartbeats.

NAS/NFS

VMFS

(Lock File)

(Heartbeat Region)
File
File Locks
Locks

File
File Locks
Locks

Virtual
Virtual Machine
Machine A
A

Virtual
Virtual Machine
Machine C
C

Virtual
Virtual Machine
Machine E
E

Virtual
Virtual Machine
Machine B
B

Virtual

Virtual Machine
Machine D
D

Virtual
Virtual Machine
Machine F
F

Default Gateway
(Isolation Address)

Slave Host
MOID:
MOID: 98
98

Failed
Master
master
host
Failed
Master Host
Host

MOID:
MOID: 99
99
MOID: 99
99 MOID:

Slave Host
MOID:
MOID: 100
100

Primary Heartbeat Network

vCenter Server

Alternate Heartbeat Network
MOID = Managed Object ID

VMware vSphere: Install, Configure, Manage
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9-24


Isolated Host
If the host does not observe
election traffic on the management
and cannot ping its default
gateway, the host is isolated.

Virtual
Virtual Machine
Machine A
A

Virtual
Virtual Machine
Machine C
C

Virtual
Virtual Machine
Machine E
E

Virtual
Virtual Machine
Machine B
B

Virtual
Virtual Machine
Machine D
D

Virtual
Virtual Machine
Machine F
F

ESXi Host

ESXi Host

ESXi Host

Default Gateway

Primary Heartbeat Network
Alternate Heartbeat Network

(Isolation Address)

VMware vSphere: Install, Configure, Manage
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