Virtual machines are protected in virtual protection groups (VPGs). A VPG is a group of virtual machines that you group together for recovery purposes. For example, the virtual machines that comprise an application like Microsoft Exchange, where one virtual machine is used for the software, one for the database, and a third for the Web Server require that all three virtual machines be replicated to maintain data integrity.

Once a virtual machine is protected, all changes made on the machine are sent to the remote site. The remote site can be recovered to any point in time defined for the VPG or if a period further in the past is required, an offsite backup can be restored.

Any virtual machine whose operating system is supported in both the protected site and AWS can be protected in a VPG.

When a VPG is created, application data and the data required to recreate the protected virtual machines are copied to AWS during a process of synchronization. This synchronization between the protected site and AWS takes time, depending on the size of the virtual machines.

After the initial synchronization completes, only the writes to disk from the virtual machines in the protected site are sent to AWS. These writes are stored by the Virtual Replication Appliance (VRA) in the journals in an S3 bucket for a specified period, after which they are promoted to the replica virtual disks managed by the VRA, which are also in an S3 bucket.

The number of VPGs that can be defined on a site is limited only by the number of virtual machines that can be protected. Each site can manage a maximum of 5000 virtual machines.