This IDC Flash evaluates LeftHand Networks' Virtual SAN Appliance (VSA) for VMware ESX, a new software appliance that creates virtual shared iSCSI storage using the LeftHand SAN/iQ storage software platform running on top of VMware ESX. A new approach for the storage industry, the LeftHand VSA runs as a virtual machine on each ESX system. The LeftHand SAN/iQ software, within the VSA, encapsulates the internal or local storage of a series of ESX servers. It aggregates this storage as a pool, presenting it back to the ESX servers or other servers on the network as an iSCSI shared storage cluster.