The Zerto Virtual Replication product features two software components: the Zerto Management Server and the Zerto Virtual Appliance. The Zerto Management Server resides on the VMware vCenter Server as a plug-in to the vCenter Client. A Zerto Linux-based Virtual Appliance sits on each ESX host for which it's replicating virtual machines. Each Virtual Appliance is installed on the ESX host by an automated process from the Management Server.
The Zerto Virtual Appliance software is deployed on top of VMware's vSphere cloud software. Zerto's software looks at the I/O stream associated with a given virtual machine (either a VMDK or VMware Raw Device Mapping) and continuously replicates data from user-selected VMs, compressing and sending that data to the remote site over WAN links. Each Virtual Appliance handles its own load and replication process and there is no need for any data movement between ESX hosts.
"We are agnostic to storage; you can have a combination of vendor arrays, and we can replicate to another third-party array," said Gil Levonai, vice president of products at Zerto.
Laura DuBois, an analyst at market research firm IDC, said Zerto's replication product created a new market segment.
"Zerto leverages continuous replication in concert with a checkpoint process, rather than array or VM-level snapshots. This allows for point-in-time recovery from checkpoints, which are taken every few seconds. Thus organizations can use Zerto not only for business continuity and disaster recovery but also for recovery from logical errors and corruption," DuBois wrote in a white paper.
Zerto claims to have become the first vendor to launch a hypervisor-based data replication product when it shipped its product in June. VMware followed suit in August, with its vSphere SRM 5.0 data replication feature. With the Zerto Virtual Replication product, asynchronous replication occurs at the VMDK level rather than at the storage LUN level.
According to Zerto, it offers the same scalability, performance levels, recovery time objectives and recovery point objectives found in array-based replication products. The product includes WAN optimization and compression, automated failover and failback, and signature mapping to re-sync changed blocks during a WAN recovery.
ARA tested a beta version of Zerto's software earlier this year, and both Thomas and Yudell were impressed. "It did everything the guys said it would," Thomas said.
They plan to have ARA's virtualization project, including installation of Zerto's product, completed within a year.
"So VMware allows us to decouple hardware from software," Thomas said. "And Verto's replication technology does that for our replication strategy."
Lucas Mearian covers storage, disaster recovery and business continuity, financial services infrastructure and healthcare IT for Computerworld. Follow Lucas on Twitter at @lucasmearian, or subscribe to Lucas's RSS feed. His email address is email@example.com.
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