When you decide on the placement of the VMkernel swap file of the virtual machines running in the management domain of VMware Cloud Foundation, consider the configuration efforts and traffic related to transferring virtual machine system data across the data center.

When a virtual machine is powered on, the system creates a VMkernel swap file to serve as a backing store for the contents of the virtual machine's RAM. By default, the swap file is stored in the same location as the configuration file of the virtual machine.

Because co-locating the swap and configuration files of a virtual machine leads to additional replication traffic when replicating virtual machines to a failover VMware Cloud Foundation instance, to reduce the amount of this traffic, you can change the swap file location on the ESXi host. However, the completion of vSphere vMotion operations might take longer when the swap file must be recreated on a new datastore because pages swapped to a local swap file on the source host must be transferred across the network to the destination host.

Table 1. Design Decisions on the Virtual Machine Swap Configuration of the ESXi Hosts

Decision ID

Design Decision

Design Justification

Design Implication


For workloads running in the default management cluster, save the virtual machine swap file at the default location.

Simplifies the configuration process.

Increases the amount of replication traffic for management workloads that are recovered as part of the disaster recovery process.