6.5
Table Of Contents
- Using VMware vSphere Replication
- Contents
- About Using VMware vSphere Replication
- Replicating Virtual Machines
- How the Recovery Point Objective Affects Replication Scheduling
- How the 5 Minute Recovery Point Objective Works
- How Retention Policy Works
- Replicating a Virtual Machine and Enabling Multiple Point in Time Instances
- Using vSphere Replication with Virtual SAN Storage
- Using vSphere Replication with vSphere Storage DRS
- How vSphere Replication Synchronizes Data Between vCenter Server Sites During Initial Configuration
- Replicating Virtual Machines Using Replication Seeds
- Replicating a Virtual Machine in a Single vCenter Server Instance
- Best Practices For Using and Configuring vSphere Replication
- Configure Replication for a Single Virtual Machine to vCenter Server
- Configure Replication for Multiple Virtual Machines to vCenter Server
- Move a Replication 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 Point in Time Settings of a Replication
- Change the Target Datastore Location of a Replication
- Monitoring and Managing Replications in vSphere Replication
- Performing a Recovery with vSphere Replication
- Troubleshooting vSphere Replication
- Generate vSphere Replication Support Bundle
- 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
- 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 Operations Fail with Authentication Error
- 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
- Configuring Replication Fails Because Another Virtual Machine has the Same Instance UUID
- Not Active Replication Status of Virtual Machines
- 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
- Unable to Establish an SSH Connection to the vSphere Replication Appliance
- The Replication Pauses When You Add a New Disk To the Source VM
- The vSphere Replication Appliance Root File System Switches to Read-only Mode and Login Fails
Because user-friendly names of Virtual SAN datastores might change and cause errors during replication
or recovery operations, vSphere Replication automatically replaces the user-friendly name of a datastore
with its UUID, which is constant. Therefore, the UUID is displayed everywhere in the vSphere Replication
user interface, though you selected a human-readable name during replication configuration.
Limits of Using vSphere Replication with Virtual SAN Storage
For reasons of load and I/O latency, Virtual SAN storage is subject to limits in terms of the numbers of
hosts that you can include in a Virtual SAN cluster and the number of virtual machines that you can run
on each host. See the Limits section in the VMware Virtual SAN Design and Sizing Guide at
http://www.vmware.com/products/virtual-san/resources.html.
Using vSphere Replication adds to the load on the storage. Every virtual machine generates regular read
and write operations. Configuring replications on those virtual machines adds another read operation to
the regular read and write operations, which increases the I/O latency on the storage. The precise
number of virtual machines that you can replicate to Virtual SAN storage by using vSphere Replication
depends on your infrastructure. If you notice slower response times when you configure replications for
virtual machines in Virtual SAN storage, monitor the I/O latency of the Virtual SAN infrastructure.
Potentially, reduce the number of virtual machines that you replicate in the Virtual SAN datastore.
Note When you stop a replication, vSphere Replication does not delete the replica directory at the target
datastore. As a result, stale directories remain on VMFS and NFS target datastores, and unused
namespaces remain on Virtual SAN and Virtual Volume target datastores. Because the maximum number
of directories and namespaces on a datastore is limited, you must manually clean them up to free
resources on the datastore. See Clean Up the Target Datastore After You Stop a Replication.
Retaining Point-in-Time Snapshots when Using Virtual SAN
Storage
Virtual SAN storage stores virtual machine disk files as a set of objects and components. Each disk object
in Virtual SAN storage has mirror and witness objects. In the default Virtual SAN storage policy, a disk
object has 2 mirrors and one witness. The number of mirror components is determined by the size of the
virtual machine disk and the number of failures to tolerate that you set in your Virtual SAN storage policy.
A mirror object is divided into components of a maximum size of 256 GB each.
n
If a virtual machine has one 256 GB disk and you use the default Virtual SAN storage policy, the disk
object will have 2 mirror components of 256 GB each and 1 witness, to make a total of 3 components.
n
If a virtual machine has one 512 GB disk and you use the default Virtual SAN storage policy, the disk
object will have 4 mirror components of 256 GB each and 1 witness, to make a total of 5 components.
See the VMware Virtual SAN Design and Sizing Guide at
http://www.vmware.com/products/virtual-san/resources.html for explanations of objects, components,
mirrors, witnesses, and Virtual SAN storage policies.
Using VMware vSphere Replication
VMware, Inc. 10