vSphere Replication and Bandwidth Requirements
By: Ivan Talley, Systems Engineer at VMware Customers often ask me how much bandwidth they’ll need for VMware vSphere Replication. It’s a pretty typical question, especially when they’re using vCenter Site Recovery Manager (SRM) for disaster recovery. In general, I’m not a fan of ambiguous answers from vendors. Unfortunately, this is a case where the […]]> By: Ivan Talley, Systems Engineer at VMware
Customers often ask me how much bandwidth they’ll need for VMware vSphere Replication. It’s a pretty typical question, especially when they’re using vCenter Site Recovery Manager (SRM) for disaster recovery.
In general, I’m not a fan of ambiguous answers from vendors. Unfortunately, this is a case where the ambiguous answer is correct — we just don’t know what you’ll need. It depends on how many virtual machines (VMs) you intend to replicate, how frequently you intend to do so, and how much their data changes. Each variable impacts the actual amount of data that needs to be moved. This calculation must be performed before you can determine your bandwidth needs.
You’ll need to do some math to determine the optimal connection speed because replication likely isn’t the only traffic on your connection.
You can find a free tool, one I often suggest to customers, at a lesser-known VMware site. It’s a “fling,” an unsupported software project that our engineers delve into on occasion, but it always fills a need for someone, somewhere. Sometimes flings even become product features.
Anyways, the fling you’ll need is available at https://labs.vmware.com/about. Search this page for “replication” to find the replication tool. You should find the following summary:
The vSphere Replication Capacity Planning Appliance allows administrators to model the network impact of a virtual machine replication without producing actual replication traffic. The appliance provides command-line tools to configure replication for any VM in a vSphere Virtual Center. The replication is established in preview mode and thus requires no storage space. Networking traffic, required for the replication, is measured and displayed in an easy-to-understand graphical format that allows you to estimate the network bandwidth required.
Use this tool to get an accurate calculation on how virtual machine replication will impact your network. Once you do this, you should get a better estimate on how much bandwidth you’ll need as well. I hope this was helpful, and if you find yourself needing additional estimates or tweaks, I’d suggest checking the fling site out.
Of course, if you’re ever in need of something, don’t hesitate to drop us a line.
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Ivan Talley has over 20 years of experience as a Network Engineer in medium size business data centers. His expertise also includes multiple verticals such as consulting engineering, contract electronics manufacturing, waste management, and legal services.