Disaster recovery using Zerto Virtual Replication enables recovering from a disaster to any point between the moment just before the disaster and a specified amount of time in the past up to 30 days. The recovery is done in real time at the recovery site with a minimal RTO.

Virtual machines are protected in VPGs. Once a VPG is created, Zerto Virtual Replication creates a copy under the management of a Virtual Replication Appliance, VRA, on the recovery site, of the protected virtual machine files, such as the configuration and data files. A VRA is installed on every host where the machines are to be recovered.

When a recovery operation is performed, the VRA creates the virtual machines defined in the VPG and attaches the virtual disks to these machines. It then promotes the data from the journal to the virtual machine disks.

When a recovery operation is performed, there is often a need to reconfigure the IP of the VM after being cloned. By defining re-IP, this process occurs automatically during recovery operations.

After initializing the VPG, all writes to the protected virtual machines are sent by the VRA on the relevant host for each virtual machine on the protected site to the VRA on the recovery site specified as the recovery host for the virtual machine. The information is saved in the journal for the virtual machine with a timestamp, ensuring write-fidelity. Every few seconds the Zerto Virtual Manager causes a checkpoint to be written to every journal on the recovery site for every virtual machine in the VPG, ensuring crash-consistency.

The data remains in the journal until the time specified for the journal when it is moved to the relevant mirror disks, also managed by the VRA for the virtual machine. In this way, you can recover the virtual machines using the mirror disks and then promoting the data from the journal to include the final few hours of data for each virtual machine. Refer to “The Role of the Journal During Protection”, on page 40 for more details about the journal.