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Table Of Contents
vSphere Replication Operations Run Slowly as the Number of
Replications Increases
As you increase the number of virtual machines that you replicate, vSphere Replication operations can
run more slowly.
Problem
Response times for vSphere Replication operations can increase as you replicate more virtual machines.
You possibly experience recovery operation timeouts or failures for a few virtual machines, and RPO
violations.
Cause
Every virtual machine in a datastore generates regular read and write operations. Configuring
vSphere Replication on those virtual machines adds another read operation to the regular read and write
operations, which increases the I/O load on the storage. The performance of vSphere Replication
depends on the I/O load of the virtual machines that you replicate and on the capabilities of the storage
hardware. If the load generated by the virtual machines, combined with the extra I/O operations that
vSphere Replication introduces, exceeds the capabilities of your storage hardware, you might experience
slow response times.
Solution
When running vSphere Replication, if response times are greater than 30 ms, reduce the number of
virtual machines that you replicate to the datastore. Alternatively, increase the capabilities of your
hardware. If you suspect that the I/O load on the storage is an issue and you are using VMware Virtual
SAN storage, monitor the I/O latency by using the monitoring tool in the Virtual SAN interface.
VMware vSphere Replication Administration
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