What is a possible purpose for this volume?

During installation you manually create a local VMFS volume. What is a possible purpose for this volume?

A.
service console swap files for over commitment of service console RAM

B.
decentralized storage for all VMkernel swap activity

C.
VMkernel swap files for locally configured virtual machines

D.
storage for service console log files

Explanation:
Best Practices for vSphere (ESX 4) Service Console Partitions

The swap partition is used to supplement RAM if the service console runs out of physical memory. Therefore A is incorrect.

In-depth ESX Server service console partitioning and provisioning

Because ESX Server’s Service Console is based on Red Hat Enterprise Linux, it places its log files in /var/log. Therefore D is incorrect.

The Role of Memory in VMware ESX Server 3, page 3.

When you power on a virtual machine, a corresponding swap file is created and placed in the same location as the virtual machine configuration file (.vmx file). The virtual machine can power on only when the swap file is available. Therefore C is incorrect.

Mastering Vmware vSphere 4, page 219.

Local storage is still used by default in vSphere ESX 4 installations as the ESX userworld swap (think of this as the ESX host swap and temp use). Therefore B is correct.