Release Notes

11 VMware vSphere Virtual Volumes on Dell PS Series | 2028-N-WP-V
- See section 3.2, “Types of Virtual Volumes” for details on the different types of virtual volumes that are in
a virtual machine.
3.2 Types of Virtual Volumes
Traditionally, a virtual machine consisted of a VMX (configuration) file, one or more VMDK files, a VSWP (memory
swap) file, log files, and other miscellaneous files. With Virtual Volumes, a virtual machine consists of a collection of
virtual volumes on the SAN that consume space from the Storage Container space reservation. A vVol-based virtual
machine consists of the following types of virtual volumes:
• Config: This small VMFS-formatted thick provisioned 4 GB volume hosts the VMX file, log files, and other
miscellaneous files.
• Data: The equivalent of a VMDK, one exists for each virtual disk attached to the virtual machine. Data virtual
volumes, sometimes referred to as VMFS virtual volumes, are always thin provisioned.
• Swap: The equivalent of the VSWP file, it is created when the virtual machine is powered on. It is thick
provisioned and is the same size as the memory assigned to the virtual machine, less any memory reservation.
When a VMware snapshot is taken of the virtual machine, vSphere offloads this operation to the SAN that creates a
hardware-based snapshot. Two more virtual volume types that can exist in this case are:
• Snapshot: Created for each Data virtual volume associated with the virtual machine snapshot, and stores the
delta of changes since the previous snapshot was taken. Snapshot virtual volumes are hidden in the PS Series
interface, but the number of snapshots associated with a data virtual volume is indicated by the number in the
snapshot column.
• Memory: Created if the option to include a memory dump with the snapshot is selected, it is equal to the size
of the memory assigned to the virtual machine.