5.8
Table Of Contents
- VMware vSphere Replication Administration
- Contents
- vSphere Replication Administration
- Updated Information
- Overview of VMware vSphere Replication
- vSphere Replication Roles and Permissions
- vSphere Replication System Requirements
- Installing vSphere Replication
- Deploying Additional vSphere Replication Servers
- Upgrading vSphere Replication
- Reconfigure the vSphere Replication Appliance
- Reconfigure General vSphere Replication Settings
- Change the SSL Certificate of the vSphere Replication Appliance
- Change the Password of the vSphere Replication Appliance
- Change Keystore and Truststore Passwords of the vSphere Replication Appliance
- Configure vSphere Replication Network Settings
- Configure vSphere Replication System Settings
- Reconfigure vSphere Replication to Use an External Database
- Use the Embedded vSphere Replication Database
- Replicating Virtual Machines
- How the Recovery Point Objective Affects Replication Scheduling
- Replicating a Virtual Machine and Enabling Multiple Point in Time Instances
- Using vSphere Replication with Virtual SAN Storage
- Replicating Virtual Machines Using Replication Seeds
- Replicating a Virtual Machine in a Single vCenter Server Instance
- Configure Replication for a Single Virtual Machine to vCenter Server
- Configure Replication for Multiple Virtual Machines to vCenter Server
- Move a Virtual Machine to a New vSphere Replication Server
- Stop Replicating a Virtual Machine
- Reconfiguring Replications
- Reconfigure Recovery Point Objectives (RPO) in Replications
- Resize the Virtual Machine Disk Files of a Replication that Uses Replication Seeds
- Resize Virtual Machine Disk Files of a Replication that Does Not Use Replication Seeds
- Change the Target Datastore Location
- Change the Point in Time Settings of a Replication
- Performing a Recovery with vSphere Replication
- Monitoring and Managing Replications in vSphere Replication
- Troubleshooting vSphere Replication
- vSphere Replication Limitations
- Access the vSphere Replication Logs
- vSphere Replication Events and Alarms
- Solutions for Common vSphere Replication Problems
- Error at vService Bindings When Deploying the vSphere Replication Appliance
- OVF Package is Invalid and Cannot be Deployed
- Connection Errors Between vSphere Replication and SQL Server Cannot be Resolved
- Application Quiescing Changes to File System Quiescing During vMotion to an Older Host
- Configuring Replication Fails for Virtual Machines with Two Disks on Different Datastores
- vSphere Replication Service Fails with Unresolved Host Error
- Scalability Problems when Replicating Many Virtual Machines with a Short RPO to a Shared VMFS Datastore on ESXi Server 5.0
- vSphere Replication Sites Appear in the Not Authenticated State
- Error Recovering Virtual Machine in a Single vCenter Server Instance
- vSphere Replication RPO Violations
- vSphere Replication Appliance Extension Cannot Be Deleted
- vSphere Replication Does Not Start After Moving the Host
- Unexpected vSphere Replication Failure Results in a Generic Error
- Increase the Memory of the vSphere Replication Server for Large Deployments
- Reconnecting Sites Fails If One Of the vCenter Servers Has Changed Its IP Address
- Uploading a Valid Certificate to vSphere Replication Results in a Warning
- vSphere Replication Server Registration Takes Several Minutes
- Generating Support Bundles Disrupts vSphere Replication Recovery
- vSphere Replication Operations Take a Long Time to Complete
- vSphere Replication Does Not Display Incoming Replications When the Source Site is Inaccessible
- vSphere Replication is Inaccessible After Changing vCenter Server Certificate
- vSphere Replication Cannot Establish a Connection to the Hosts
- Anti-virus Agent in Firewall Terminates Virtual Machine Replication
- Initial Full Synchronization of Virtual Machine Files to VMware Virtual SAN Storage Is Slow
- vSphere Web Client 5.1.x Non-Functioning Option Binds vSphere Replication Traffic to a Specific vmknic
- Configuring Replication Fails After Rebuilding VRMS
- vSphere Replication Operations Run Slowly as the Number of Replications Increases
- Error at Reconfiguring the vSphere Replication Management Server from the Virtual Appliance Management Interface
If you use volume shadow copy service (VSS) to quiesce the virtual machine, replication traffic cannot be
spread out in small sets of bundles throughout the RPO period. Instead, vSphere Replication transfers all
the changed blocks as one set when the virtual machine is idle. Without VSS, vSphere Replication can
transfer smaller bundles of changed blocks on an ongoing basis as the blocks change, spreading the
traffic throughout the RPO period. The traffic changes if you use VSS and vSphere Replication handles
the replication schedule differently, leading to varying traffic patterns.
If you change the RPO, vSphere Replication transfers more or less data per replication to meet the new
RPO.
Link Speed
If you have to transfer an average replication bundle of 4GB in a one hour period, you must examine the
link speed to determine if the RPO can be met. If you have a 10Mb link, under ideal conditions on a
completely dedicated link with little overhead, 4GB takes about an hour to transfer. Meeting the RPO
saturates a 10Mb WAN connection. The connection is saturated even under ideal conditions, with no
overhead or limiting factors such as retransmits, shared traffic, or excessive bursts of data change rates.
You can assume that only about 70% of a link is available for traffic replication. This means that on a
10Mb link you obtain a link speed of about 3GB per hour. On a 100Mb link you obtain a speed of about
30GB per hour.
To calculate the bandwidth, see Calculate Bandwidth for vSphere Replication.
Calculate Bandwidth for vSphere Replication
To determine the bandwidth that vSphere Replication requires to replicate virtual machines efficiently, you
calculate the average data change rate within an RPO period divided by the link speed.
If you have groups of virtual machines that have different RPO periods, you can determine the replication
time for each group of virtual machines. For example, you might have four groups with RPO of 15
minutes, one hour, four hours, and 24 hours. Factor in all the different RPOs in the environment, the
subset of virtual machines in your environment that is replicated, the change rate of the data within that
subset, the amount of data changes within each configured RPO, and the link speeds in your network.
Prerequisites
Examine how data change rate, traffic rates, and the link speed meet the RPO. Then look at the
aggregate of each group.
Procedure
1 Identify the average data change rate within the RPO by calculating the average change rate over a
longer period then dividing it by the RPO.
2 Calculate how much traffic this data change rate generates in each RPO period.
3 Measure the traffic against your link speed.
For example, a data change rate of 100GB requires approximately 200 hours to replicate on a T1
network, 30 hours to replicate on a 10Mbps network, 3 hours on a 100Mbps network.
VMware vSphere Replication Administration
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