Impact of VM swap file placement
The creation of a VM's swap file is automatic. By default, this file is created in the VM's working directory, but a different location can be set.
Swap file contains swapped memory pages and its size is determined as allocated RAM size—reservation. If performance is important in the design, 100 percent memory reservations should be created, causing no need to swap to disk.
You can optionally configure a special host cache on an SSD (if one is installed) to be used for the swap to host cache feature. This swap cache is shared by all the VMs running on the host. In addition, host-level swapping of the VMs' most active pages benefits from the low latency of SSD. The swap to host cache feature makes the best use of potentially limited SSD space. This feature is also optimized for large block sizes where some SSDs work best.
If a host does not use the swap to host cache feature, place the VM swap files on low latency, high bandwidth storage systems. The best choice...