Objective 4.4 Configure and manage vSphere Replication

Overview

VMware vSphere Replication is an extension to VMware vCenter Server that provides hypervisor-based virtual machine replication and recovery.

vSphere Replication replaces storage-based replication. It protects virtual machines from partial or complete site failures by replicating the virtual machines from a primary site to a secondary site.

With vSphere Replication, you can replicate virtual machines from a primary datacenter to a secondary sit quickly and efficiently. After you set up the replication infrastructure, you can choose the virtual machines to be replicated at a different recovery point objective (RPO).

You can configure all vSphere Replication features in the vSphere Web Client. You monitor the status of a replication through the replication management and monitoring dashboard.

Certain vSphere editions include the license for vSphere Replication.

vSphere Replication does not have a separate license. You can use vSphere Replication if you have an edition of vSphere that includes the vSphere Replication license.

  • vSphere Essentials Plus
  • vSphere Standard
  • vSphere Enterprise
  • vSphere Enterprise Plus

If you have the correct vSphere license, there is no limit on the number of virtual machines that you can replicate by using vSphere Replication.

You cannot use vSphere Replication to replicate virtual machines on ESXi hosts that do not have the correct

vSphere license. You can install vSphere Replication on an ESXi host that does not have the correct license, but attempts to configure replication on virtual machines on that host fail with a licensing error.

If you configure a virtual machine for replication on a host with the correct vSphere license and move it to a host with an unsupported license, vSphere Replication stops replication of that virtual Machine.

vSphere Replication has certain operational limits.

To ensure successful virtual machine replication, you must verify that your virtual infrastructure respect certain limits before you start the replication.

You can only deploy one vSphere Replication appliance on a vCenter Server instance. Deploying more than one vSphere Replication appliance is not prohibited, but might lead to unexpected results.

Each vSphere Replication management server can manage a maximum of 500 replicated virtual machines.

See http://kb.vmware.com/

  • Configure and manage a vSphere Replication infrastructure

Deploying the vSphere Replication Virtual Applicance.

The vSphere Replication Appliance can be downloaded from here

https://my.vmware.com/web/vmware/details?productId=352&downloadGroup=VR550_GA

1 Log in to the vSphere Web Client on the source site.

2 Select vCenter > Hosts and Clusters.

3 Right-click a host and select Deploy OVF template.

4 Provide the location of the OVF file from which to deploy the vSphere Replication appliance, and click Next.

  • Select URL and provide the URL to deploy the appliance from an online URL.
  • Select Local file > Browse to locate the .ovf file if you downloaded the zip file to a local machine.

5 Review the virtual appliance details and click Next.

6 Accept the end user license agreements (EULA) and click Next.

7 Accept the default name and destination folder or datacenter, or provide a new name and select a folder or datacenter for the virtual appliance, and click Next.

8 Select a cluster, host, vApp, or resource pool where you want to run the deployed template, and click Next.

9 Select a destination datastore and disk format for the virtual appliance and click Next.

10 Select a network from the list of available networks, IP protocol, IP allocation, and click Next.

vSphere Replication supports both DHCP and static IP addresses. You can also change network settings by using the virtual appliance management interface (VAMI) after installation.

11 Set the password for the root account for the customized template, and click Next.

Password must be eight characters minimum.

12 Review the binding to the vCenter Extension vService and click Next.

13 Review the settings, select the check box to power on the virtual appliance after deployment, and click Finish.

The vSphere Replication appliance is deployed.

14 Log out of the vSphere Web Client, close the browser, then log back in.

vSphere Replication is present on the Home tab in the vSphere Web Client.

At this stage the Replication icon didnt appear in the Web Client for me, I had to restart my vCenter instance to recieve the icon

15 Repeat the procedure to install vSphere Replication on the target site.

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Under Home> vSphere Replication. Right click the local vCenter and scroll down to “All vSphere Replication Actions”

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To add a target site, select the  “Connect to target site” icon & fill in the required details to connect to the target vCenter

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On the recent Tasks pane you should see that the job “Connect VR sites” has completed successfully.

Click on the “manage” icon on the home tab (shown below)

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You can then see the connected target sites that have been configured and are connected

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Multiple Target sites can be configured by following the same instructions as set out above.

You may also want to deploy multiple replication appliances to meet load balancing needs, you can find the offcial documentation here

 

  • Configure and manage vSphere Replication of virtual machines

When you set a Recovery Point Objective (RPO) value during replication configuration, you determine the maximum data loss that you can tolerate. The RPO value affects replication scheduling, but vSphere Replication does not adhere to a strict replication schedule.

For example, when you set the RPO to 15 minutes, you instruct vSphere Replication that you can tolerate losing the data for up to 15 minutes. This does not mean that data is replicated every 15 minutes.

1 On the vSphere Web Client Home page, click VMs and Templates.
2 Browse the inventory to find the single virtual machine to replicate using vSphere Replication.
3 Right-click the virtual machine and select All vSphere Replication Actions > Configure replication.

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4 Select the target site.

    • If you have already connected the source and target sites, select the target site from the list.
    • If you have not connected the source and target sites, and the target site is local, select the target site from the list.

If you have not connected the source and target sites, and the target site is remote, click Add Remote Site and enter the IP or name, and credentials to connect to the site.

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5 Accept the automatic assignment of a vSphere Replication server or select a particular server on the target site.

If you had multiple Replication servers configured on the vCenter you could use this setting to load balance replication.

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6 Select the target location datastore. Optionally, you can select the virtual machine storage policy.

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7 If you select Advanced disk configuration, you can configure the virtual machine’s individual disks one at a time.

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For each disk you can select its virtual format, storage policy, and specify a datastore where it is replicated. Disable replication of the disk by deselecting Enable disk replication.

8 Select a Guest OS Quiescing configuration, if applicable to the source virtual machine operating system.

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9 Use the RPO slider or enter a value to configure the maximum amount of data that can be lost in the case of a site failure. Optionally, enable point in time instances and specify instance retention policy.

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The available RPO range is from 15 minutes to 24 hours.
10 Review the settings and click Finish to establish replication.

vSphere Replication starts an initial full synchronization of the virtual machine files to the designated datastore on the target site.

Replication can be monitored from the vSphere Replication option, on the Home tab then the “Monitor” option

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You will be able to see the replication Percentage, the RPO, the Target site, the VR Server that is pushing the replication and the last Sync Duration.

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It is worth keeping an eye on the Sync Duration

Assume that during replication configuration you set the RPO to 15 minutes. If the replication starts at 12:00 and it takes five minutes to transfer to the target site, the instance becomes available on the target site at 12:05, but it reflects the state of the virtual machine at 12:00. The next replication can start no later than 12:10.

This replication instance is then available at 12:15 when the first replication instance that started at 12:00 expires.

If you set the RPO to 15 minutes and the replication takes 7.5 minutes to transfer an instance, vSphere Replication transfers an instance all the time. If the replication takes more than 7.5 minutes, the replication encounters periodic RPO violations. For example, if the replication starts at 12:00 and takes 10 minutes to transfer an instance, the replication finishes at 12:10. You can start another replication immediately, but it finishes at 12:20. During the time interval 12:15-12:20, an RPO violation occurs because the latest available instance started at 12:00 and is too old.

  • Troubleshoot vSphere Replication

It’s hard to list all troubleshooting scenerios here, there’s a guide to solving common issues here but ultimately hands on experience is required.

As you should only register a single vSphere Replication Appliance with vCenter, a plasuable question in the exam could be that a Replication server previously exsisted and has been deleted, the appliance could still be registered with vCenter which would prevent you from adding a new Replication Appliance.

Below is the process to Unregister vSphere Replication from vCenter Server if the Appliance Was Deleted.

1

In the extensionList property, click the corresponding link for the com.vmware.vcHms extension key to check the key details.

2

Verify that the displayed data is for a vSphere Replication appliance that is already lost.

3

In ExtensionManager, click unregisterExtension.

4

Type com.vmware.vcHms for the extension key value, and click Invoke Method.

5

Verify that the result displays void and not an error message.

An error message might appear if the specified extension is not registered, or if an unexpected runtime error occurs.

6

Close the window.

7

Refresh the ExtensionManager page and verify that the extensionList entry does not include com.vmware.vcHms.

 

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