Datastores are logical containers, similar to file systems, that contain specific information of each storage device and provide a uniform model for storing virtual machine files.

You can use datastores to store ISO images, virtual machine templates, and floppy images.

Depending on the type of storage you use, datastores can be of the following types:

  • Virtual Machine File System (VMFS)
  • Network File System (NFS)

You can increase the datastore capacity after you create a datastore but only if it is a VMFS datastore.

Block storage devices, Fibre Channel and iSCSI, and NAS devices support the hardware acceleration.

The hardware acceleration functionality enables the ESXi host to integrate with compliant storage systems. The host can offload certain virtual machine and storage management operations to the storage systems. With the storage hardware assistance, your host performs these operations faster and consumes less CPU, memory, and storage fabric bandwidth.

For more information, see the VMware knowledge base article at http://kb.vmware.com/kb/1021976.