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Dell VMware VSAN Ready Nodes vLab Guide

Converged Infrastructure

Dell confidential

Dell

Document version 1.0

Date: May 2016


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Table of Contents

Demonstration Labs ........................................................................................................................... 4

Introduction ....................................................................................................................................... 4

Preparing the Demo Environment ................................................................................................ 5

Module 1 - All Flash VSAN 6.2 Cluster (30 Minutes) ........................................................................ 6

All Flash VSAN Cluster........................................................................................................................... 6

View Available Storage Devices ...................................................................................................... 8

Enable Virtual SAN on the cluster ................................................................................................... 9

Turn on Virtual SAN ......................................................................................................................... 10

Verify Network validation ............................................................................................................... 11

Enable the VMkernel VSAN traffic service ................................................................................... 12

Enable Virtual SAN on the cluster ................................................................................................. 14

Turn On Virtual SAN ........................................................................................................................ 15

Verify Network validation ............................................................................................................... 17

Ready to Complete ......................................................................................................................... 20

Verify VSAN Health .......................................................................................................................... 24

Module 1 - Conclusion ................................................................................................................... 33

Module 2 - Enabling Performance Service (30 Minutes) ......................................................... 34

Enabling Performance Service .......................................................................................................... 34

Monitor Virtual SAN Performance - Cluster ............................................................................... 39

Module 2 - Conclusion .................................................................................................................. 41

Module 3 - Storage Based Policy Management (30 Minutes)................................................. 42

Storage Based Policy Management ................................................................................................. 42

Raid 5/6 (Erasure coding) ............................................................................................................... 45

Disk Policies - FTT=1 Raid 5 .......................................................................................................... 56

Implement Raid 6 - Disk Policies .................................................................................................. 59

Module 4 - Sparse VM Swap Object (30 Minutes) ..................................................................... 62

New Sparse VM Swap Object ............................................................................................................ 62

New Sparse VM Swap Object ........................................................................................................ 63

Module 4 - Conclusion .................................................................................................................. 64


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Module 5 - Virtual SAN Stretched Cluster (ROBO) (30 Minutes) ........................................... 65

Virtual SAN Stretched Cluster (ROBO) ............................................................................................. 65

Configure Virtual SAN Stretched Cluster .................................................................................... 66

vSphere HA and DRS settings for VSAN Stretched Cluster ...................................................... 84

VM/Host Groups .............................................................................................................................. 85

Enabling HA in VSAN Stretched Cluster ...................................................................................... 90

Module 5 - Conclusion ...................................................................................................................... 105


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Demonstration Labs

Introduction

This lab covers the new features in Virtual SAN 6.2

There are 5 modules in the training:

1. All Flash VSAN Cluster : Virtual SAN clusters contain two or more physical hosts that

contain either a combination of magnetic disks and flash devices ( hybrid configuration ) or

all flash devices ( all-flash configuration ) that contribute cache and capacity to the Virtual

SAN distributed datastore. Virtual SAN uses deduplication and compression to eliminate

duplicate data. These techniques reduce the total storage required to meet your needs.

2. Enabling Performance Service: When you create a new Virtual SAN cluster, the

performance service is disabled. Turn on Virtual SAN performance service to monitor the

performance of Virtual SAN clusters, hosts, disks, and VMs. When you turn on the

performance service, Virtual SAN places a Stats database object in the datastore to collect

statistical data. The Stats database is a namespace object that resides in the cluster's Virtual

SAN datastore. In this task you will enable the performance service.

3. Storage Based Policy Management: Virtual SAN 6.2 introduces space efficiency

technologies optimized for all-flash configurations to minimize storage capacity

consumption while ensuring performance and availability. These new features include

RAID5/6 erasure coding to reduce capacity consumption while ensuring the same levels of

availability and performance for a lower total cost of ownership. Another SPBM feature is

Object Checksum. This will ensure that you have data integrity in your VSAN Cluster.

Checksum is available on both hybrid and all-flash configurations of VSAN.

4. Sparse VM Swap Object: This new feature can provide a considerable space-saving on

capacity space consumed by deploying VM swap as thin. This will rely on how many VMs you

have deployed, and how large the VM swap space is (essentially the size of unreserved

memory assigned to the VM).

5. Virtual SAN Stretched Cluster : Features such as Fault Domains, 2-node VSAN and VSAN

stretched cluster now have new wizards to make the whole setup process very straight-

forward. The goal of keeping VSAN “radically simple” is still at the heart of VSAN

development.


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Preparing the Demo Environment

Activation Prompt or Watermark

When you first start your lab, you may notice a watermark on the desktop indicating that

Windows is not activated.

One of the major benefits of virtualization is that virtual machines can be moved and run on

any platform. The Hands-on Labs utilizes this benefit and we are able to run the labs out of

multiple datacenters. However, these datacenters may not have identical processors, which

triggers a Microsoft activation check through the Internet.

Rest assured, Dell and demos.dell.com are in full compliance with Microsoft licensing

requirements. The lab that you are using is a self-contained pod and does not have full

access to the Internet, which is required for Windows to verify the activation. Without full

access to the Internet, this automated process fails and you see this watermark.

This cosmetic issue has no effect on your lab. If you have any questions or concerns, please

feel free to contact us.

A note on the keyboard

Note : If you are not using a US keyboard be aware that the “ and @ symbols may be reversed

or in different locations, depending on how you connect.


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You can click on the Keyboard icon on the System Tray of the ControlCenter VM to pop up an

onscreen keyboard.

Module 1 - All Flash VSAN 6.2 Cluster (30 Minutes)

All Flash VSAN Cluster

Virtual SAN can be configured with all-flash or hybrid storage. Typically in earlier versions of

VSAN there is just one flash disk (SSD) per disk group, for read and write caching. All the other

disks in the disk group are used for capacity, and are regular magnetic SAS or SATA hard

disks. This is known as hybrid VSAN configuration.

Creating an All Flash Virtual SAN means that flash disks (SSDs ) can be used for both caching

and for capacity tiers.

An All Flash VSAN datastore can be configured using just the vSphere Web Client.

Log in to vSphere Web Client

To start the vSphere Web Client, launch Mozilla Firefox from the icon on your desktop.

Log in to the vSphere Web Client using the following credentials or tick the Use Windows

session authentication


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User name : [email protected] Password : VMware1!

Click Login

Navigate to Hosts and Clusters

From the Home page in the vSphere Web Client, select Hosts and Clusters from the

Inventories pane


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View Available Storage Devices

1. Select the ESXi host called esx-01a.corp.local from the Hosts and Clusters view.

2. Select Manage

3. Select Storage

4. Select Storage Devices

The Disks highlighted above are Flash Disks. There are 2 disks of 5 GB in size and will be used

for caching tier, the other 4 are 10 GB in size and will be used for capacity tier.

These are the Disks that we will use to form the VSAN Cluster.

Check the other three hosts (esx-02a.corp.local, esx-03a.corp.local, esx-04a.corp.local)

and confirm that they too have 2 X 5 GB and 4 X 10 GB Flash disks.

It is now time to form our VSAN Cluster.


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Enable Virtual SAN on the cluster

1. Select the cluster called Cluster Site A

2. Select Manage

3. Select Settings

4. Select Virtual SAN

5. Select General

6. Click the Configure... button


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Turn on Virtual SAN

Here we will introduce the new Configure Virtual SAN wizard.

From here you can decide if you want to select Manual or Automatic disk claiming, if you

want to enable Deduplication and Compression when creating the Disk Groups and options

for Fault Domains and Stretched Cluster.

In our environment, we already have a VSAN Cluster created, but we will turn it on. We will

also look at the additional checks that we have incorporated into the Virtual SAN

configuration wizard.

Verify Add disks to storage is set to Manual

Verify Deduplication and Compression is Enabled

Verify Fault Domains and Stretched Cluster is set to Do Not configure

To get a quick overview of these features, click the information (i) next to the feature.

Click Next


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Verify Network validation

Checks have been put in to verify that there are VMkernel adapters configured and the VSAN

network service is Enabled.

Notice that the ESXi host called esx-04a.corp.local is reporting that there are no VMkernel

adapters with VSAN traffic enabled.

Let's fix this by enabling the VSAN traffic on these VMkernel adapters.

Click Cancel


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Enable the VMkernel VSAN traffic service

1. Select the ESXi host called esx-04a.corp.local from the Hosts and Clusters view.

2. Select Manage

3. Select Networking

4. Select VMkernel adapters

Here you will see that we have 2 VMkernel adapters called VSAN-PG-vmk3 and VSAN-PG-

vmk4. These are the 2 VMkernel adapters on which we will enable the VSAN traffic Service.

Select VSAN-PG-vmk3 and click the Pencil icon to Edit the VMkernel adapter.


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In the Port Properties, select the Virtual SAN traffic option.

Click OK


Edit the Properties of the VSAN-PG-vmk4 and enable the Virtual SAN traffic.

Click OK


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Once we have enabled the Virtual SAN traffic on the VMkernel ports, verify that the Virtual

SAN traffic is enabled.

Here we are showing the 2 VMkernel Ports and the Virtual SAN traffic is enabled.

You may have to scroll to the right of the screen to see the Virtual SAN traffic column.

Now that we have completed this task, let’s create our Virtual SAN Cluster.

Enable Virtual SAN on the cluster


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2. Select Manage

3. Select Settings

4. Select General

5. Click the Configure... button

Turn On Virtual SAN


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In our environment, we already have a VSAN Cluster created, but we will turn it on. We will

also look at the additional checks that we have incorporated into the Virtual SAN

configuration wizard.

Verify Add disks to storage is set to Manual

Verify Deduplication and Compression is Enabled

Verify Fault Domains and Stretched Cluster is set to Do Not configure

To get a quick overview of these features, click the information (i) next to the feature.

Click Next


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Verify Network validation

Checks have been put in to verify that there are VMkernel adapters configured and the VSAN

network service is Enabled.

Notice that the ESXi host called esx-04a.corp.local is now reporting that there are VMkernel

adapters with VSAN traffic enabled.

Click Next


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Claim Disks by Disk model/size

As we called out earlier, we are turning on VSAN. We already have a VSAN cluster created,

but here we are adding additional Disk Groups to the VSAN Cluster.

Select which disks should be claimed for cache and which for capacity in the VSAN cluster.

The disks are grouped by model and size or by host.

The recommended selection has been made based on the available devices in your

environment. You can expand the lists of the disks for individual disk selection.

The number of capacity disks must be greater than or equal to the number of cache disks

claimed per host.

From the Group by drop down list, select Host


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Claim Disks by Host

In the Group by : Host view, we can see that all the disks are already claimed in the ESXi

hosts called esx-01a.corp.local, esx-02a.corp.local and esx-03a.corp.local.

For ESXi host called esx-04a.corp.local, we can see that there will be 2 Disk Groups created,

that is one Flash disk and 2 Capacity disks in each Disk Group.

Click Next


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Ready to Complete

Review and verify your selection.

Here we can see that Deduplication and Compression are Enabled.

We will have a Total VSAN capacity of 160 GB, 120 GB of this is already claimed in Disk

Groups, the remaining 40 GB will be created when we create the additional Disk Group on

the ESXi host called esx-04a.corp.local

We are not configuring Fault Domains and Stretched Cluster

Click Finish


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Wait for cluster reconfiguration to complete

You can monitor the tasks by clicking on the My Tasks at the bottom left of the vSphere Web

Client.

Wait for the Reconfigure Virtual SAN configuration tasks to complete.

Verify initial VSAN cluster configuration

Once the VSAN datastore is created, the General screen will be updated.

We can see that Virtual SAN is now Turned On. Deduplication and compression is Enabled

and all disks in the Disk Groups are at Disk format version 3.0.


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Examine new Disk Groups


2. Select Manage

3. Select Settings

4. Select Disk Management

The Virtual SAN Disk Group(s) will be created on each individual ESXi Host.

Selecting an ESXi Host or Disk Group will show the disks it contains and the role each disk

plays (cache or capacity).


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Examine new Disk

You can change to the disks view by clicking on the Disks link on the top right of this screen


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Verify VSAN Health

A number of VSAN Health alarms are triggered during the VSAN cluster configuration

process.

These can be ignored, and/or acknowledged and reset to green. They do not affect the rest

of the lab.

For the Hardware compatibility test, these will always show as a Warning as we are running

in a virtualized environment.

If you see Network Partition failures, wait for a moment and run the tests again.

Click the Retest button to run the VSAN Health Check again.


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Verify VSAN Health

Expand the Hardware Compatibility.

Here you can see that we have checked the Hardware ( Controller Driver, Controller

Release, and SCSI Controller ) from the VMware Hardware Compatibility List.

In our Lab environment, these will always show as a warning as we are running in a

virtualized environment.


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Verify VSAN Health

Expand the Performance service.

The Performance service is showing as a warning because we have not enabled it yet. We

will do this in a later task.


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Virtual SAN HCL Database

Select the Cluster Cluster Site A -> Manage -> Settings -> Health and Performance

The Virtual SAN HCL DB can be kept up to date from the Health and Performance screen.

You can upload an updated HCL db from a file or you can update from the online version.

Note: You may not have an Internet connection from your lab environment, so you will not

be able to update the HCL Database.

Examine the new VSAN datastore


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1. Switch to the Datastores view.

2. Select the new VSAN datastore (vsanDatastore)

3. Review the basic details in the Summary tab.

We have now successfully created an All Flash VSAN Cluster.

Get VSAN information from the command line (esxcli vsan)


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Open the PuTTY icon on your desktop.

Select the session called esx-01a.corp.local , you will be automatically logged in to the ESXi

Host.

For reference, the root password is VMware1!

Get VSAN Cluster information


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The vSphere CLI command set allows you to run common system administration commands

against vSphere systems from an administration server of your choice.

'esxcli vsan' is the namespace for VSAN management commands.

To get help, run 'esxcli vsan --help'

[root@esx-01a:~] esxcli vsan Usage: esxcli vsan {cmd} [cmd options] Available Namespaces: cluster Commands for VSAN host cluster configuration datastore Commands for VSAN datastore configuration network Commands for VSAN host network configuration storage Commands for VSAN physical storage configuration faultdomain Commands for VSAN fault domain configuration maintenancemode Commands for VSAN maintenance mode operation policy Commands for VSAN storage policy configuration trace Commands for VSAN trace configuration

To get information on the Virtual SAN Cluster that this host is joined to, run the following

command:

esxcli vsan cluster get

The command esxcli vsan cluster get, when run on individual ESXi hosts, can tell if a host is

participating in the Virtual SAN cluster.

Running the command on an ESXi host that is part of a healthy 4-node VSAN cluster is

shown above.

The local node UUID can be retrieved from the output. You can also see the Sub-Cluster

Member UUIDS, of which there are four.

Get VSAN Network information


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To participate in a Virtual SAN cluster, and form a single partition of fully connected ESXi

hosts, each ESXi host in a VSAN cluster must have a vmknic (VMkernel NIC or VMkernel

adapter) configured for Virtual SAN traffic.

Note: Even if an ESXi host is part of the Virtual SAN cluster, but is not contributing storage, it

must still have a VMkernel NIC configured for Virtual SAN traffic.

Query VSAN network configuration at the ESXi host level:

esxcli vsan network list

In our output, the VMkernel nic vmk3 and vmk4 are used for Virtual SAN traffic.

We can also see the Multicast configuration from this output.

Get VSAN Storage information


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Query local disk information in the ESXi host:

esxcli vsan storage list

We can use esxcli vsan storage list to check if the Disk is an SSD disk, if the disks are claimed

by CMMDS ( Cluster Monitoring, Membership, and Directory Service). We can also see the

On-disk format version.

We can also check whether Deduplication and Compression are enabled.


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Finally, whether the disk is participating in the Cache or Capacity tier in the VSAN diskgroup.

Get VSAN Policy information

Query the default policy in the VSAN cluster:

esxcli vsan policy getdefault

By default, an N+1 failures to tolerate policy is applied so that even in the case where user

forgets to create and set a policy objects are made resilient. It is not recommended to

change the default policy.

Module 1 - Conclusion

In this module we walked through the steps to enable an all-flash VSAN Cluster. We

demonstrated the new Virtual SAN configuration wizard and the additional VSAN traffic


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VMkernel checks. We added an additional Disk group to the VSAN cluster to increase the

capacity of the vsanDatastore. We took our first look at the VSAN Health Check. Finally we

looked at some of the command line ( esxcli ) tools to query information about the VSAN

cluster configuration.

Module 2 - Enabling Performance Service (30 Minutes)

Enabling Performance Service

When you create a new Virtual SAN cluster, the performance service is disabled. Turn on

Virtual SAN performance service to monitor the performance of Virtual SAN clusters, hosts,

disks, and VMs.

When you turn on the performance service, Virtual SAN places a Stats database object in the

datastore to collect statistical data. The Stats database is a namespace object that resides in

the cluster's Virtual SAN datastore.

Before you enable the Virtual SAN performance service, make sure the cluster is properly

configured and has no outstanding health issues.

With the release of the Virtual SAN 6.2 Performance Service, VMware is providing basic

Virtual SAN performance reporting from the vSphere Web Client. The goals are to have this

feature “always on”, fully integrated with the vSphere Web Client UI, easy to access and

consume, and maintain historic data of VSAN performance.

A Virtual SAN namespace object is used to store a statistics database (stats DB). The object is

a regular object (stats object), and has a policy associated with it. The policy is chosen when

the administrator enables the performance service. If no specific policy is chosen, the default

VSAN datastore policy is used. The default policy has NumberOfFailuresToTolerate set to 1,

which implies that if there is a failure in the VSAN cluster, the performance service is not

impacted and will continue to run. Therefore the performance service has no single point of

failure.

On each ESXi host in the VSAN cluster, the performance service runs a daemon to collect

performance metrics. The metrics are calculated as an average over 5 minute intervals. The

stats collection is always on. These statistics are stored in the stats DB in the stats object. This

implies that the vCenter server is not required for any aspect of the stats infrastructure, such

as setup, collection, storage, and query.



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When you create a new Virtual SAN cluster, the performance service is disabled.

To enable the performance service, VSAN must be configured on the cluster.

Select the Cluster called Cluster Site A

Select Manage

Select Settings

Select Health and Performance

Click Edit



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Select the Turn On Virtual SAN performance service check box.

Select a storage policy for the Stats database object.

Select the Virtual SAN Default Policy

The Virtual SAN Default Storage Policy is selected by default. This includes the policy

attribute of NumberOfFailuresToTolerate set to 1, making the performance service highly

available.

Click OK



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Check the Recent Tasks pane.

The Enable Virtual SAN performance service task will be executed.


Select Cluster Site A -> Manage -> Settings -> Health and Performance

On examining the status of the performance service after it has been enabled, a status similar

to the following should now be seen.

From here you can also Turn off or Edit the Storage policy in use by the Performance

service.



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Select Cluster Site A -> Monitor -> Virtual SAN -> Health

Click the Retest button to rerun the VSAN Health Check

Here we can see that the Performance service Health Checks have now passed, once we

have enabled the Performance service.

Expand the Performance service and select the individual Performance service checks for

more information.


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Monitor Virtual SAN Performance - Cluster

Select Cluster Site A -> Monitor -> Performance -> Virtual SAN - Virtual Machine

Consumption

You can use Virtual SAN performance service to monitor the performance of your Virtual

SAN environment, and investigate potential problems.

The performance service collects and analyzes performance statistics and displays the data in

a graphical format so that you can determine the root cause of problems. You can view

performance charts for the cluster, and for each host, disk group, and disk in the Virtual SAN

cluster. You also can view performance charts for virtual machines and virtual disks.

The Virtual SAN Performance Service displays performance charts that you can use to

monitor the workload and help you determine the root cause of problems.

When the Performance Service is turned on, the cluster Summary displays an overview of

Virtual SAN performance statistics, including Virtual SAN capacity, throughput, IOPS, and

latency. At the cluster level, you can view detailed statistical charts for virtual machine

consumption and the Virtual SAN back-end.

We have no Performance data to graph yet, but we can return to these Performance

Graphs in later modules.


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Monitor Virtual SAN Performance - Cluster

Select Cluster Site A -> Monitor -> Performance -> Virtual SAN - Backend

Virtual SAN displays performance charts for the host back-end operations, including IOPS,

throughput, latency, congestion's, and outstanding IOs.

We do not have any data to show yet. On each ESXi host in the VSAN cluster, the

performance service runs a daemon to collect performance metrics.

The metrics are calculated as an average over 5 minute intervals.


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Monitor Virtual SAN Performance - Hosts

There are similar Performance Graphs available at a Host level.

Select esx-01a.corp.local > Monitor -> Performance

The graphs available here are :

Virtual SAN - Virtual Machine Consumption

Virtual SAN - Backend

Virtual SAN - Disk Group

Virtual SAN – Disk


In this module we showed how to enable the VSAN Performance service which is disabled by

default. The new VSAN performance service will have its own separate database on the VSAN

datastore and can be protected with a VM Storage Policy. All the graphs for the performance

service can be found under the Performance > Monitor view when a cluster, host or VM is

selected in the vCenter server inventory. It's now easy to monitor Virtual SAN from within the

vSphere Web Client.


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Module 3 - Storage Based Policy Management (30 Minutes)

Storage Based Policy Management

When you use Virtual SAN, you can define virtual machine storage requirements, such as performance

and availability, in the form of a policy. Virtual SAN ensures that the virtual machines deployed to

Virtual SAN datastores are assigned at least one virtual machine storage policy.

Once assigned, the storage policy requirements are then pushed down to the Virtual SAN layer when a

virtual machine is being created. The virtual device is distributed across the Virtual SAN datastore to

meet the performance and availability requirements.

When you know the storage requirements of your virtual machines, you can create a storage policy

referencing capabilities that the datastore advertises.

You can create several policies to capture different types or classes of requirements.


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Storage based Policy Management

Virtual SAN 6.2 adds a number of new Storage Policies, namely Disable object checksum,

Failure tolerance method and IOPs limit for object.

We are giving a brief description of each of the Storage Policies here.

Number of disk stripes per object - The number of capacity devices across which each

replica of a virtual machine object is striped. A value higher than 1 might result in better

performance, but also results in higher use of system resources.

Flash read cache reservation - Flash capacity reserved as read cache for the virtual machine

object. Specified as a percentage of the logical size of the virtual machine disk (vmdk) object.

Reserved flash capacity cannot be used by other objects. Unreserved flash is shared fairly

among all objects. This option should be used only to address specific performance issues.

Number of failures to tolerate - Defines the number of host and device failures a virtual

machine object can tolerate. For n failures tolerated, n+1 copies of the virtual machine object

are created and 2*n+1 hosts contributing storage are required.

Force provisioning - If the option is set to Yes, the object will be provisioned even if the

policy specified in the storage policy is not satisfiable by the datastore. Use this parameter in

bootstrapping scenarios and during an outage when standard provisioning is no longer

possible.

Object space reservation - Percentage of the logical size of the virtual machine disk (vmdk)

object that should be reserved, or thick provisioned when deploying virtual machines.

Disable object checksum - If the option is set to No, the object calculates checksum

information to ensure the integrity of its data. If this option is set to Yes, the object will not

calculate checksum information. Checksums ensure the integrity of data by confirming that


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each copy of a file is exactly the same as the source file. If a checksum mismatch is detected,

Virtual SAN automatically repairs the data by overwriting the incorrect data with the correct

data.

Failure tolerance method - Specifies whether the data replication method optimizes for

Performance or Capacity. If you choose Performance, Virtual SAN uses more disk space to

place the components of objects but provides better performance for accessing the objects.

If you select Capacity, Virtual SAN uses less disk space, but reduces the performance.

IOPS limit for object - Defines the IOPS limit for a disk. IOPS is calculated as the number of

IO operations, using a weighted size. If the system uses the default base size of 32KB, then a

64KB IO represents two IO operations. When calculating IOPS, read and write are considered

equivalent, while cache hit ratio and sequentially are not considered. If a disk’s IOPS exceeds

the limit, IO operations will be throttled. If the IOPS limit for object is set to 0, IOPS limits are

not enforced.


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Raid 5/6 (Erasure coding)

Note that there is a requirement on the number of hosts needed to implement RAID-5 or

RAID-6 configurations on VSAN.

For RAID-5, a minimum of 4 hosts are required; for RAID-6, a minimum of 6 hosts are

required.

The objects are then deployed across the storage on each of the hosts, along with a parity

calculation. The configuration uses distributed parity, so there is no dedicated parity disk.

When a failure occurs in the cluster, and it impacts the objects that were deployed using

RAID-5 or RAID-6, the data is still available and can be calculated using the remaining data

and parity if necessary.

A new policy setting has been introduced to accommodate the new RAID-5/RAID-6

configurations.


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This new policy setting is called Failure Tolerance Method. This policy setting takes two

values: performance and capacity. When it is left at the default value of performance, objects

continue to be deployed with a RAID-1/mirror configuration for the best performance. When

the setting is changed to capacity, objects are now deployed with either a RAID-5 or RAID-6

configuration.

The RAID-5 or RAID-6 configuration is determined by the number of failures to tolerate

setting. If this is set to 1, the configuration is RAID-5. If this is set to 2, then the configuration

is a RAID-6.

Storage based Policy Management - Raid 5/6 (Erasure coding)

Select Home -> Policies and Profiles -> VM Storage Policies

Select Create a New VM Storage policy


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Create a new VM Storage Policy using the following information

Name : FTT=1-Raid5

Click Next


Click Next on the Rule-Sets information page

Create a new Rule-Set using the following information:

Rules based on data services : VSAN Rule 1 : Number of failures to tolerate = 1 Rule 2 : Failure tolerance method = Raid-5/6 (Erasure Coding)-Capacity


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Before you click next, check out the following:

Change the Failure tolerance method = RAID-1 (Mirroring) - Performance

Review the Storage Consumption Model on the right hand side of the screen. Notice that

the Storage space that would be used would be 200 GB based on a virtual disk of 100 GB.

Now change the Failure tolerance method = Raid-5/6 (Erasure Coding)-Capacity and you

will see that the Storage space will now be reduced to 133 GB.

Click Next


The Storage compatibility will be determined based on the VM Storage Policy.

Here we can see that the vsanDatastore is compatible with the VM Storage Policy that we

are about to create.

Click Next



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Review the VM Storage Policy Settings

Click Finish


Select FTT=1-Raid5 -> Manage -> Rule-Set-1:VSAN

Here we can see the rules that make up our VM Storage Policy.

Virtual SAN Capacity - Raid 5/6 (Erasure coding )


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Select Home -> Hosts and Clusters

Select Cluster Site A -> Monitor -> Virtual SAN -> Capacity

Make a note of the capacity figures here.

Clone VM to VSAN datastore - Raid 5/6 (Erasure coding)


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We will clone the VM called linux-micro-01a ( which currently resides on an NFS datastore )

to the VSAN Datastore and apply the VM Storage Policy ( FTT=1-Raid5 ) that we have just

created.

Right click the VM called linux-micro-01a and select Clone -> Clone to Virtual Machine

Clone VM to VSAN datastore - Raid 5/6 (Erasure coding )


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Give the VM a name called FTT=1-Raid5

Click Next



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Select the Compute resource called Cluster Site A

Click Next


For the VM Storage Policy, select FTT=1-Raid5


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The resulting list of compatible datastores will be presented, in our case the vsanDatastore.

In the lower section of the screen we can see that the Virtual SAN storage consumption

would be 1.33 GB disk space and 0.00 B reserved Flash space.

Since we have a VM with 1 GB disk and a VM Storage Policy of Raid 5, the VSAN disk

consumption will be 1.33 GB disk.

Click Next

Click Next on the Select clone options

Clone VM to VSAN datastore - Raid 5/6 (Erasure coding )

Click Finish

Wait for the Clone operation to complete.

Check the Recent Tasks for a status update on the Clone virtual machine task.



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Once the clone operation has completed, select the VM called FTT=1-Raid5

Select Summary -> VM Storage Policies

Here we can see that the VM Storage Policy for this VM is set to FTT=1-Raid5 and the policy

is compliant.

Select Summary -> Related Objects

The VM is now residing on the vsanDatastore


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Disk Policies - FTT=1 Raid 5

Select the VM FTT=1-Raid5 -> Monitor -> Policies -> Hard Disk 1 -> Physical Disk Placement

Notice with this VM Storage Policy, we have a Raid 5 disk placement, made up of 4

Components.

There is one component residing on each host in the Cluster.


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Virtual SAN Capacity - Raid 5/6 (Erasure coding)

To allow administrators to track where the storage consumption is occurring a brand new

capacity view has been introduced with VSAN 6.2.


If we focus on the Capacity Overview first of all, we can see the full size of the VSAN

datastore. This is approximately 160 GB in size. We can also see Deduplication and

compression overhead.

The amount of space Used – Total on the VSAN datastore refers to how much space has

been physically written (as opposed to logical size). This is a combination of Virtual disks, VM

home objects, Swap objects, Performance management objects and Other items that may

reside on the datastore. Other items could be ISO images, unregistered VMs, or templates,

for example.

The Deduplication and Compression overview on the top right gives administrators an idea

around the space savings and deduplication ratio that is being achieved, as well as the

amount of space that might be required if an administrator decided that they wanted to

disable the space efficiency features on VSAN and re-inflate any deduplicated and

compressed objects.

The space savings ratio increases with the more “similar” VMs that are deployed.

This is telling us that without deduplication and compression, it would have required ~ 9.5 GB

of capacity to deploy the current workloads. With deduplication and compression, we’ve

achieved it with ~ 4.25 GB.


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Virtual SAN Capacity - Raid 5/6 (Erasure coding)


Towards the bottom of the Capacity Screen, we will get a breakdown of the objects.

Group by Object Types:

Performance management objects: Capacity consumed by objects created for storing

performance metrics when Performance service is enabled

File system overhead: Any overhead taken up by the on-disk file system (VirstoFS) on the

capacity drives, which is neither attributed to deduplication, compression or checksum

overhead. When deduplication and compression is enabled, file system overhead is increased

10X to reflect the increase in the logical size of the VSAN datastore.

Deduplication and compression overhead: Overhead incurred to get the benefits of

deduplication and compression. This includes the associated mapping table, hash tables, and

other mechanisms required for deduplication and compression.

Checksum overhead: Overhead to store all the checksums. When deduplication and

compression are enabled, checksum overhead is increased 10X to reflect the increase in the

logical size of the VSAN datastore.

When a VM and a template are deployed on the VSAN datastore, more objects appear:

Virtual disks: Capacity consumed by Virtual machine disks (VMDKs) objects that reside on the

VSAN datastore


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VM home objects: Capacity consumed by VM home namespace objects (containing virtual

machine files) residing on the VSAN datastore

Swap objects: Capacity consumed by VM Swap space that reside on the VSAN datastore

Vmem – Capacity consumed by memory Objects, created as a result of taking a snapshot of

the VM which included the VM memory, or from suspended virtual machines. Note that this

will only be visible on VMs that are using a minimum of Virtual Hardware V10.

Other: Capacity consumed by VM templates, unregistered VMs, standalone VMDKs not

associated with VMs, manually created VSAN objects, manually created directories that store

ISOs for example.

Implement Raid 6 - Disk Policies

Your Lab environment is currently running a 4 Node VSAN Cluster. To implement Raid 6,

you would require a minimum of 6 hosts in the VSAN Cluster.

The VM Storage Policy will have a Failure Tolerance Method of Raid 5/6 - ( Erasure Coding )

- Capacity and the Number of failures to tolerate set to 2.

In a Raid-6 you will consume x1.5 times the storage assigned to the VM.


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Implement Raid 6 - Disk Policies

Here is an example of a VM with a Raid 6 VM Storage Policy Configuration.

In the Raid 6 configuration, there are 6 components and they are spread out across the 6

ESXi hosts in the Cluster.


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Storage based Policy Management - Object Checksum

VSAN 6.2 introduces another new feature, end-to-end software checksum, to help

customers avoid data integrity issues arising due to problems on the underlying storage

media. In VSAN 6.2, checksum is enabled by default, but may be enabled or disabled on per

virtual machine/object basis via VM storage policies.

Checksum is enabled by default as we feel customers will always want to leverage this great

new feature. The only reason one might disable it is if the application already has this

functionality included.

Brief Overview of Checksum on Virtual SAN

Checksum on VSAN is implemented using the very common cyclic redundancy check CRC-

32C (Castagnoli) for best performance, utilizing special CPU instructions on Intel processors.

Every 4KB block will have a checksum associated with it. The checksum is 5 bytes in size.

When the data is written, the checksum is verified on the same host where the data

originates to ensure that if there is any corruption in-flight over the network, it is caught. The

checksum is persisted with the data.

Scrubber mechanism

Alongside the checksum verification on read operations, VSAN also has a scrubber

mechanism which checks that the data on disk does not have any silent corruption. This

scrubber is designed to check all of the data once a year, but this can be tuned via the

advanced setting VSAN.ObjectScrubsPerYear to run more often. For instance, if you want

this to check all of the data once a week, set this to 52, but be aware that there will be some

performance overhead when this operation runs.


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Module 4 - Sparse VM Swap Object (30 Minutes)

New Sparse VM Swap Object

Those of you who have a good understanding of VSAN at this stage will know that a virtual

machine deployed on the VSAN datastore is deployed as a set of objects, and not a set of

files, which is how a VM is deployed on traditional datastores. Those objects include the VM

Home Namespace, VMDKs and of course VM Swap.

VM Swap is interesting, in that it only exists when the VM is powered on, but on VSAN it has

always been provisioned with 100% Object Space Reservation in the past.

This has some drawbacks, since it tended to consume a lot of capacity. For example, if I

deployed 100 VMs, each with 8 GB of memory, then there is 800 GB of disk provisioned for

the VM swap.

This is reserved space that I may never even use if the VM never experiences resource issues.


To show this example, the only VM that we need powered on in our environment is the VM

called FTT=1-Raid5 that we created earlier.

If you have other VM's running, power them off now.

In the VM called FTT=1-Raid5, we can see that we have 64 MB memory assigned.

Note the ESXi host that the VM is running on, it may be different than shown here.


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Now switch to the Capacity View.


Scroll to the bottom of the Capacity View to the Used Capacity Breakdown section.

Here we can see the Swap Objects are taking around 140 MB


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Power Off the VM called FTT=1-Raid5

As expected, there are no VM swap objects consuming space on the VSAN datastore.


In this module we showed you that in Virtual SAN 6.2, we have a way of deploying the Virtual

Machine Swap object as thin.

In environments where Virtual Machines rely on over-committing Memory, disabling the

Sparse VM Swap Object is not recommended. In this scenario, Virtual Machines will need

their swap file when there are no memory pages available.


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Module 5 - Virtual SAN Stretched Cluster (ROBO) (30 Minutes)

Virtual SAN Stretched Cluster (ROBO)

Stretched clusters extend the Virtual SAN cluster from a single site to two sites for a higher

level of availability and intersite load balancing. Stretched clusters are typically deployed in

environments where the distance between data centers is limited, such as metropolitan or

campus environments.

You can use stretched clusters to manage planned maintenance and avoid disaster scenarios,

because maintenance or loss of one site does not affect the overall operation of the cluster.

In a stretched cluster configuration, both sites are active sites. If either site fails, Virtual SAN

uses the storage on the other site. vSphere HA restarts any VM that must be restarted on the

remaining active site.

You must designate one site as the preferred site. The other site becomes a secondary or

non-preferred site. The system uses the preferred site only in cases where there is a loss of

network connection between the two active sites, so the one designated as preferred is the

one that remains operational.

A Virtual SAN stretched cluster can tolerate one link failure at a time without data becoming

unavailable. A link failure is a loss of network connection between the two sites or between

one site and the witness host. During a site failure or loss of network connection, Virtual SAN

automatically switches to fully functional sites.


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Configure Virtual SAN Stretched Cluster

Today, Virtual SAN introduces Virtual SAN for Remote Office Branch Office (ROBO), a

supported solution specifically designed and packaged to satisfy the demands of smaller

ROBO environments and suitable use cases.

Virtual SAN for ROBO is built on the foundation of Fault Domains, where in this case the

required failure zones are based on three nodes (two physical nodes and witness virtual

appliance). The witness virtual appliance is uniquely designed with the sole purpose of

providing cluster quorum services during failure events and to store witness objects and

cluster metadata information.

The use of the witness virtual appliance eliminates the requirement of a third physical node.

This is what ROBO customers were looking for as lower costs is one of the cornerstones for

ROBO use cases.

A couple of facts about the Virtual SAN Witness Virtual Appliance:

One witness virtual appliance is required per Virtual SAN ROBO cluster.

The appliance does not contribute compute nor storage resources to the cluster and it

is not able to host virtual machines.

The witness virtual appliance is exclusively available and supported ONLY for Virtual

SAN Stretched Clusters and Virtual SAN ROBO edition.


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Much like the Virtual SAN Stretched Cluster, the Virtual SAN ROBO edition is only

capable of supporting a single failure within the cluster (FTT=1) due to the support of only

three fault domains.

We have already deployed out this VSAN Witness host for you in this environment. The ESXi

host is registered as esx-07a.corp.local.

Note : The color representing the Witness host is a light blue in color to help you identify it

in your vSphere environment.


Select the ESXi host called esx-07a.corp.local

Select Manage

Select Storage

Select Storage Devices

The VSAN Witness host has One Flash ( cache ) and one HDD ( capacity ).

We will use these to create the diskgroup for the VSAN Witness host.


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We will now configure the Stretched Cluster or Two Host Virtual SAN cluster.

Select ROBO Cluster

Select Manage

Select Settings

Select Virtual SAN -> General

Click Configure


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For the Disk Claiming, select Add disks to Storage as Manual

In the Fault Domains and Stretched Cluster section, select Configure two host Virtual SAN

cluster

Click Next



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Verify that the VMkernel ports have VSAN traffic enabled.

Click Next



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Select which disks should be claimed for Cache tier and for the Capacity tier in the VSAN

cluster.

The disks can be grouped by model/size or by host.

The recommended selection has been made based on the available devices in your

environment.

The number of capacity disks must be greater than or equal to the number of cache disks

claimed per host.

Click Next



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Select the esx-07a.corp.local as the VSAN witness host.

The Requirements for the witness hosts are listed on the screen.

Click Next



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Select the 10 GB disks for the Cache tier.

Select the 15 GB disk for the Capacity tier.

Click Next


Review settings and click Finish.



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Review the Recent Tasks pane.


Once the tasks have completed, your VSAN Stretched Cluster will be formed.

We can see that the Stretched Cluster has been enabled, the Preferred fault domain is

called Preferred and the VSAN witness host is esx-07a.corp.local

Lower down in the screen we can see the 2 Fault Domains that were created, each fault

domain containing one ESXi host.

Virtual SAN Object Health


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Select ROBO Cluster

Select Monitor

Select Virtual SAN

Select Health

We have a new region in the Health check for Stretched Cluster.

Verify Stretched Cluster Health


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Expand the Stretched Cluster health check.

Here you will see the health checks related to VSAN Stretched Cluster.

vSphere High Availability (HA) and Distributed Resource Scheduler (DRS) settings for VSAN

Stretched Cluster

To provide availability for virtual machines in a VSAN Stretched Cluster, vSphere High

Availability (HA) needs to be configured.

This allows VMs to be restarted on the same site (with affinity rules) when there is a host

failure, or restarted on the remote site when there is a complete site failure. However, there

are certain settings that need to be configured in a specific way that are fundamental to

achieving high availability in a VSAN stretched cluster.

In this task, we will call out the VMware recommended settings and we will also explain why

we are recommending that vSphere HA be configured in this way on a VSAN Stretched

Cluster.

By following this guidance, you can be sure that your virtual machines get restarted on the

same site (maintaining read locality) when there is a component/host failure on one site. It

will also ensure that the virtual machines failover and restart on the remaining site in the

event of a complete site failure.

Clone VM to Primary Site


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Once we have the VSAN Stretched Cluster formed, we will start by getting some Virtual

Machines deployed to the VSAN Cluster. We will achieve this by cloning the linux-micro-01a

Virtual Machine.

Right click the linux-micro-01a VM and select Clone and select Clone to Virtual Machine


Give the Virtual Machine a Name, we will call it VM-Primary, this VM will reside on the

Primary Site.


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VM Name : VM-Primary

Click Next


Select the ROBO Cluster, this is where we will initially place the VM.

Click Next


Here we will apply a VM Storage Policy for the VM. We will place the VM on the

vsanDatastore.


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Select the following VM Storage Policy:

VM Storage Policy : Virtual SAN Default Storage Policy

Click Next


Click Next on the Select Clone options


Review your settings and click Finish



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We have our first VM available, let’s repeat the same process to create a second VM, called

VM-Secondary.

Clone VM to Secondary Site


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This time we will clone the VM-Primary VM.

Right click the VM-Primary VM and select Clone and select Clone to Virtual Machine


Give the Virtual Machine a Name, we will call it VM-Secondary, this VM will reside on the

Secondary Site.


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VM Name : VM-Seondary

Click Next


Select the ROBO Cluster, this is where we will initially place the VM.

Click Next


Here we will apply a VM Storage Policy for the VM. We will place the VM on the

vsanDatastore.


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Select the following VM Storage Policy:

VM Storage Policy : Virtual SAN Default Storage Policy

Click Next


Click Next on the Select Clone options


Review your settings and click Finish


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vSphere HA and DRS settings for VSAN Stretched Cluster

We now have our 2 Virtual Machines deployed in our environment.

vSphere DRS Settings

We have already configured most of the HA and DRS settings required for a VSAN Stretched

Cluster, but we will call them out here just to show you what needs to be configured.

DRS can be setup in fully automated or partially automated mode.

For more information on setting up VSAN Cluster refer to the following link: -

http://www.vmware.com/files/pdf/products/vsan/VMware-Virtual-SAN-6.2-Stretched-Cluster-

Guide.pdf

Select ROBO Cluster - Select Manage - Select Settings - Select vSphere DRS

vSphere DRS is Turned on and in Partially Automated mode.

http://www.vmware.com/files/pdf/products/vsan/VMware-Virtual-SAN-6.2-Stretched-Cluster-Guide.pdf

http://www.vmware.com/files/pdf/products/vsan/VMware-Virtual-SAN-6.2-Stretched-Cluster-Guide.pdf


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VM/Host Groups

Now let’s consider DRS in VSAN stretched cluster.

The first DRS consideration is in the relationship of the VM/Host affinity rules.

DRS is needed for VM/Host affinity rules work. If DRS is not enabled, the “should” rules are

ignored. So if you want to use VM/Host affinity “should” rules, you will need DRS.

Select the cluster called ROBO Cluster

Select Manage

Select Settings

Select VM/Host Groups

Select Primary

The Primary Host Group contains the ESXi host called esx-05a.corp.local

Click Secondary

The Secondary Host Group contains the ESXi host called esx-06a.corp.local


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VM/Host Groups

Let's have a look at the VM Groups now.

Select the Primary-VM Group.

At the moment we do not have any VM's assigned to the VM Group.

Note : One thing to remember here is, if you deploy additional VM's in the VSAN Stretched

Cluster, remember to add these VM's to the VM Group so that they can be handled by DRS.

In the VM/Host Group Members, select Add

VM/Host Groups


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Select the VM called VM-Primary and click OK

VM/Host Groups

Select the Secondary-VM Group.

At the moment we do not have any VM's assigned to the VM Group

In the VM/Host Group Members, select Add

VM/Host Groups


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Select the VM called VM-Secondary and click OK

VM/Host Groups

Verify that the VM-Secondary VM is in the Secondary-VM VM Group.

VM-Host Rules


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Let's have a look at the VM/Host Rules.

Select the PrimaryVMHosts rule.

Two important pieces of information here, first is the VM/Host Rule Details - "Virtual

Machines that are members of the VM Group should run on hosts that are members of the

Host Group."

Second is the Group Members, here we can see that the VM-Primary VM "should" run on the

host called esxi-05a.corp.local

Select the SeondaryVMHosts rule

Here we can see that the VM-Secondary VM "should" run on the host called esxi-

06a.corp.local


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Enabling HA in VSAN Stretched Cluster

To provide availability for virtual machines in a VSAN Stretched Cluster, vSphere HA needs to

be configured. This allows VMs to be restarted on the same site (with affinity rules) when

there is a host failure, or restarted on the remote site when there is a complete site failure.

However, there are certain settings that need to be configured in a specific way that are

fundamental to achieving high availability in a VSAN stretched cluster.

Select ROBO Cluster

Select Manage

Select Settings

Select vSphere HA

vSphere HA is currently Turned OFF, click Edit



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Select Turn On vSphere HA

Expand Failure conditions and VM response



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For the Response for Host Isolation, verify that Power off and restart VMs is selected.

Scroll down and expand Admission Control



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If we have a site failure all of our VMs may have to run on a single site, which is effectively

half of the overall cluster. To ensure that reservations can be met, we need to configure HA

to reserve 50% of resources (i.e. one site).

In the Admission Control section verify the following :

Define failover capacity by reserving a percentage of the cluster resources :

Reserved failover CPU capacity : 50% Reserved failover Memory capacity : 50%

Click OK to Turn on vSphere HA

Configure HA to respect VM to Host affinity rules


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There is one final setting that needs to be placed on the VM/Host Rules. This setting once

again defines how vSphere HA will behave when there is a complete site failure.

In this section called vSphere HA Rule Settings.

One of the settings is for VM to Host Affinity rules.

Verify that the VM to Host Affinity rules is set to vSphere HA should respect rules during

failover

This setting can be interpreted as follows:

• If there are multiple hosts on either sites, and one hosts fails, vSphere HA will try to restart

the VM on the remaining hosts on that site, maintained read affinity.

• If there is a complete site failure, then vSphere HA will try to restart the virtual machines on

the hosts on the other site. If the “must respect” option shown above is selected, then

vSphere HA would be unable to restart the virtual machines on the other site as it would

break the rule. Using a “should” rule allows it to do just that.

Power On VM's


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Power On the two VM's called VM-Primary and VM-Secondary.

What you should notice is that the VM-Primary is running on esxi-05a.corp.local and VM-

Secondary is running on esxi-06a.corp.local.

The VM/Host Rules that we have created have dictated this.

Check component allocation for VM-01


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Select VM-Primary

Select Monitor

Select Policies

Select Hard disk 1

Select Physical Disk Placement

The layout shows that the VM has been deployed correctly, with one component per fault

domain (Site) and with the witness component on the witness host (esx-07a.corp.local ).

As we can clearly see, one copy of the data resides on storage in Preferred Fault Domain, a

second copy of the data resides on storage in Secondary Fault Domain and the witness

component resides on the witness host and storage on the witness site.

VSAN Health Check


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Before we attempt any Failure Scenarios, confirm that the Health Checks have all passed.

Ignore any of the Hardware compatibility health warnings as we are running in a Virtualized environment and we do not have the VSAN Performance service enabled in this cluster.

Failure Scenario - Reboot a Single Host

Here we will simulate a Site Failure Scenario, we will reboot a single host that has one of the VM Components.

Select the ESXi host called esx-05a.corp.local and reboot it.

Select esx-05a.corp.local, right click and select Power -> Reboot


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Failure Scenario - Reboot a Single Host

Select OK to reboot the ESXi Host.

Absent Components


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Select the VM called VM-Primary

Select Monitor

Select Policies

Select Hard disk 1

Select Physical Disk Placement

After a while, as the ESXi host is rebooting, and the VM-Primary was failed over as part of a

HA event, you will see the VSAN Object on that Host will go Absent.

You need to be patient at this step. It may require refreshing the vSphere Web Client.

VSAN Health Check


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Select ROBO Cluster

Select Monitor -> Virtual SAN -> Health

Wait for the Health Check to complete.

Expand the Data health section and monitor the errors.

Expand the Network health and monitor the errors.

Expand Physical disk health and monitor the errors.

VM-Primary restarted on other Host


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Change back to the VM Summary view for the VM called VM-Primary

Notice that the VM has been powered up on the other ESXi host called esx-06a.corp.local

ESXi host fully booted

Wait for the ESXi hosts to fully boot and reconnect to the vCenter Server.

DRS - Partially Automated


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Since we have DRS in Partially Automated Mode, DRS will handle the initial placement of

virtual machines.

However any further migration recommendations will be surfaced up to the administrator to

decide whether or not to move the virtual machine.

The administrator can check the recommendation, and may decide not to migrate the virtual

machine.

If no DRS Recommendations are presented to you, click Run DRS Now.

Click Apply Recommendations

vSphere Tasks


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Select Home

Select Tasks

Here we can see the results of the Migrate virtual machine task, that migrated the VM called

VM-Primary from the Secondary Site (esx-06a.corp.local ) back to the Preferred Site (esx-

05a.corp.local).

Select Hosts and Clusters

VM-Primary migrated to other Host


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Select the VM called VM-Primary

Once the migration task has completed, the VM called VM-Primary is now running on the

ESXi host called esxi-05a.corp.local (Preferred Site)

VSAN Health Check


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Rerun the Health Check again and it should show that the tests have passed.


In this module we showed you how to create a two node VSAN Stretched Cluster with the

VSAN Witness Host. The Witness host gave us the quorum to create this 3 node VSAN

Cluster.

We covered the vSphere High Availability (HA) and Distributed Resource Scheduler (DRS)

configuration required for VSAN Stretched Cluster and finally we simulated a node failure in

the VSAN Stretched Cluster and we saw the VM restart on the other node in the cluster.

Once the original node was back on-line again, we saw that we had to migrate the VM back

to the Preferred Site. This was because of the VMware recommendation of having DRS in

Partially Automated mode.

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