ASAv - more info (updated 10/16/15)

    The Cisco Adaptive Security Virtual Appliance (ASAv) brings full firewall functionality to virtualized environments to secure data center traffic and multi-tenant environments.
    You can manage and monitor the ASAv using ASDM or CLI. Other management options may be available.

    Context Mode Guidelines
      Supported in single context mode only. Does not support multiple context mode.
       Failover Guidelines
    For failover deployments, make sure that the standby unit has the same model license; for example, both units should be ASAv30s.

    To read more about the supported (and unsupported) features, please refer to: