Article number
000004546
Affected Versions
7.5
8.0
8.5
Source Hypervisor
All
Target Hypervisor
Azure

Zerto Analytics Planner ZCA Sizing Recommendation

Viewed 292 times

Description

All Users with Zerto Version 7.5 and later via Planning in Zerto Analytics now can determine based on VM workloads, how many ZCAs in Azure would be required to replicate the load properly.

These are recent architectures we suspect to be problematic and are working enhancements in Planner.
Sites where many of the VM's each have multiple disks attached (greater than 20 disks per VM).
VM's that have significant spikes in IOPS for extended periods of time.
The more VMs included in the estimate, the more disks attached to these VMs, and the higher the write rate of these VMs, the more likely a lower number of ZCAs will be returned.
Remember, we have made significant performance improvements to Azure in 7.5 and those enhancements are already reflected in Planner.

Summary

Please be advised that Planner is an estimation tool to size deployments. Final resource requirements may differ from original Planner estimation depending on the final architecture. With the recent performance improvements to Azure in 7.5 we have heard of situations where customers have used Zerto Analytics Planner to estimate a ZCA count and the Planner estimate has come in low. The Zerto Analytics Team is constantly improving the Planner algorithms as we receive customer feedback.

Target Audience

All Users with Zerto Version 7.5 and later

Notice

Background

These are recent architectures we suspect to be problematic and are working enhancements in Planner.
  1. Sites where many of the VM's each have multiple disks attached (greater than 20 disks per VM).
  2. VM's that have significant spikes in IOPS for extended periods of time.
  3. The more VMs included in the estimate, the more disks attached to these VMs, and the higher the write rate of these VMs, the more likely a lower number of ZCAs will be returned.
Remember, we have made significant performance improvements to Azure in 7.5 and those enhancements are already reflected in Planner.

Actions to take

We have created this notice to make you aware as we work to solve these corner cases. We are not pushing out to our customers as the impact is limited to a few accounts and we expect to have a new iteration of the algorithms soon.
As you use Planner, remember these best practices:
  1. Allow Planner to collect data for at least 1 week before sizing. Planner will provide data immediately, but more historical data will result in more accurate recommendations.
  2. Identify times where high iops spikes occur. The date range feature in planner can collect sizing estimates during times that include the spikes and exclude the spikes. This typically produces a wider range of ZCA estimates but is better at setting expectations for the maximum ZCAs required.