How Resiliency Platform Data Mover works
The Veritas Resiliency Platform Data Mover feature of Resiliency Platform replicates all the virtual machine writes at the local (source) data center to the remote (target) data center. The replication provides a consistent copy of the data. If a disaster occurs at the source data center, Resiliency Platform can use the copy of the data on the target (remote) data center to provision and start a virtual machine on the remote data center.
To protect virtual machines using Resiliency Platform Data Mover, you group the virtual machines at the source data center into resiliency groups that use Resiliency Platform Data Mover to provide disaster recovery protection. The resiliency group is the unit of recovery, so the virtual machines that need to be recovered together must be in the same resiliency group.
During the configuration process, Resiliency Platform puts virtual machines into multiple Veritas Replication Sets and replication units associated to the virtual machine. Each Veritas Replication Set caters to a single virtual machine and includes all the disks attached to that virtual machine, including boot and data disks. Each constituent disk is referred to as a Replication Unit.
When an application or virtual machine runs, several processes perform writes to disks, in a specific order. For example, a database posts any database change to the log before writing to the table space. The term write-order fidelity means that the write order across the constituent disks or replication units is maintained at all times.
Resiliency Platform Data Mover maintains write-order fidelity for a Veritas Replication Set when the replication is in the active state. The write-order fidelity ensures that the data in the target data center is consistent. Even though data at the target data center may not be the most recent copy, Data Mover makes sure that this data is always consistent.
Resiliency Platform Data Mover tracks writes for the virtual machines on the source data center in the order in which they are received. It applies the writes on the target data center in the same order, thereby maintaining write order fidelity.
The replication includes any changes to the boot disks of the virtual machines. As a result, if a disaster occurs on the source data center, or a planned migration is performed, virtual machines can be brought up on the recovery data center. The disaster recovery operation in Resiliency Platform provisions the virtual machines in the recovery data center so that they can be brought online as part of the operation.