vSphere Replication and Zerto – What’s the Difference?
By Zerto, on 5 September, 2012
This post is the first written by vExpert Shannon Snowden, Zerto’s new Senior Technical Marketing Architect.
Stephen Foskett of Tech Field Day sent us a couple of great questions about VMware’s vSphere Replication compared to Zerto Virtual Replication via twitter over the holiday weekend. Since we had a 140-character limitation for the replies; we decided to tweet a top 10 list of differences between vSphere Replication and Zerto Replication.
We’ve never posted a comparison to another product, not on our site or blog. One reason for this is that FUD is not our thing. We think the features of Zerto Virtual Replication are outstanding because there is really no other product on the market like it.
But Stephen’s question represents one of the most common questions we were asked at VMworld. We also noticed that bloggers picked up on the VR capability discussion after VMware announced that vSphere Replication is now decoupled from VMware’s SRM (Site Recovery Manager).
So, we think it’s worth elaborating on our twitter replies here – plus we had more than ten points to make – the full comparison is here!
- vSphere Replication is available in VMware Essentials Plus and above. Zerto works with the basic VMware Essentials product
- Having vSphere Replication working in your infrastructure doesn’t provide automation/orchestration of Disaster Recovery scenario. You will need to create PowerCLI scripts to get basic automation (add to inventory, power off/power on) capability. Zerto has full automation /orchestration features.
- Each of the Virtual Machines at the Recovery Site has to be powered on manually with VR. Zerto has fully automated recovery capabilities.
- Each VM has to be reconnected to the correct network with VR in a manual recovery. Zerto is automatic.
- vSphere Replication does not have compression capability; neither does SRM. Zerto has built in compression capability and we often see a 50% compression ratio.
- IP re-addressing is a manual process with vSphere Replication. Zerto has IP address change capability built-in to the fail over plan.
- With vSphere Replication, you cannot conduct non-disruptive testing since you cannot power on the Replica VM if the original VM is still running and reachable. Zerto allows you to map to real or bubble networks on the recovery site.
- vSphere Replication has no cloning capability. Zerto allows for recovery site clones. This allows for full long-term archival backups of the VMs or file-level recovery from a Point in Time clone.
- There is no failback option in vSphere Replication, this is only included in SRM. Zerto has automatic workflow failback capability.
- There is no Point in Time recovery with vSphere Replication. Zerto allows for flexible Point in Time Recoveries.
- No Physical RDM support (Raw Device Mappings). Zerto works with physical RDMs and virtual RDMS.
- If the customer wants to add the features of SRM with vSphere Replication, only vCenter 5.x and up is supported and ESXi 4.1 and up. Zerto supports ESX 4.0 and up as well as vCenter 4.x.
- The replication in VR cannot be increased if more bandwidth is available. The replication is set per VM and the RPO (a 15 minute RPO is the best it can do – up to 24 hours) dictates how much data is replicated on a per VM basis. VMware calls this “optimized for parallel replication of multiple VMs instead of peak throughput for a single disk”.
- Replication is tracked locally and then sent to the replica site which is additional load on the primary site hosts.
- ‘Powered off’ or suspended VMs are not replicated with VR. They are only replicated when in a ‘powered on’ state.
- vSphere Replication does not work with vApps. Zerto leverages vApps to make administration easier. If a vApp is configured with a VPG, then any VM added to the vApp is automatically protected. No other vendor has this capability.
- Storage DRS (SDRS) is not supported with vSphere Replication or SRM. Zerto works with SDRS.
When you factor in that the target implementations are very different between Zerto and vSphereReplication, the capability differences make more sense.
vSphere Replication is intended for Tier 2 VMs and SMBs with low SLAs – that’s the product positioning VMware has in mind for vSphere Replication. In fact, we agree with VMware Tech Marketing Ken Werneburg’s description of vSphere Replication:
“VR does not include all the orchestration, testing, reporting and enterprise-class DR functions… but allows for individual VM protection and recovery within or across clusters.” In the primer on VR, Ken goes on to note, “It provides a solution that enables recovery time better than that of restoring from backup.”
Zerto is an “enterprise-class” Disaster Recovery product – meaning it offers a huge feature set and near-synchronous application protection with very aggressive RPO requirements and points in time recovery. Zerto also has point in time VM cloning at the recovery site that enables archival backups and file-level restorations. Along with all these features, Zerto has vCloud Director integration; full DR workflow for fail over, automated fail back and IP re-addressing.
So a more fair comparison really would be Zerto Virtual Replication vs. SRM together with array-based replication (you’d need all the array features functioning and some additional scripting for a true comparison). And as we said on twitter – each customer needs to decide what is the right product for their environment. “We agree with VMware. vSphere Replication is a data protection mechanism – not DR”