vSphere Replication 8.4 has increased scalability to support a maximum of up to 3000 configured replications.
vSphere Replication 8.6 provides support to a maximum of up to 4000 configured replications.

Please read the following information to understand the requirements that your environment must meet to support the configuration and management up to the maximum number of replications.

Please note the supported maximum for older versions of vSphere replication is only 2000

If you upgrade a vSphere Replication instance that uses the internal database to version 8.4 or newer, you must apply additional configuration to the updated appliance to enable the support of up to 3000 or more replications. See Configuring Upgraded vSphere Replication Appliances to Support up to 4000 Replications (KB 2102463).

If you plan to replicate more than 500 virtual machines, you must change the default value for event maximum age at the vSphere Replication appliance.

In addition, the maximum number of replications that a vSphere Replication Management Server can support depends on a number of factors in your environment, like bandwidth, change rate in the guest operating system of the replicated VMs, replication traffic compression, RPO period, and others.

Supported versions of vSphere and vSphere Replication 8.4 or newer should be deployed at both the source and target sites for best results.

To support up to 3000 or more replicated VMs, the source and the target site must have sufficient server, storage, and network resources to facilitate the transfer of replication data.

The average change rate in source VMs should not exceed 5% per day.

Compute Resources

• vSphere Replication database: Embedded
• Total number of virtual machines in the environment: 3000 (or up to 4000 for vSphere replication 8.6 or newer)

Storage

• Storage protocol used: fiber channel
• Total capacity of approximately 6TB at each site, source and target.

Network

The network traffic must be isolated on separate NICs as follows.

• vmnic 0 for replication management
• vmnic 1 (recommended minimum 1 Gb) for replication traffic
• vmnic 2 for NFC traffic

See Isolating the Network Traffic of vSphere Replication.

Replication Settings

• Lowest recommended average RPO value: 4 hours
• Recommended maximum percentage of replicated VMs with multiple recovery points enabled: 10%
• Network traffic compression: enabled
  NOTE: The CPU resources that a replication uses on the hosts double when traffic compression is enabled.

Lower RPO values, higher data change rates, fewer compute, network, or storage resources, might impact the number of VMs that can be replicated. Use the vSphere Replication calculator for initial guidance. Check how a replication impacts your environment by using the vSphere Replication Capacity Planning Appliance.