What are you trying to accomplish? Off the top of my head, Cloudstack, Openstack, Eucalyptus all have that capability however its all about the necessary outcome on how you implement the configuration. For that matter, GlusterFS can also accomplish the same tasks.
Thanks for your response.
There was a response in another forum that GlusterFS performance tanks with millions of files and the write speeds drop too low. The person's objective was to setup shared storage accessed via NFS exports and CIFS shares from multiple instances running across two availability zones, where high availability and automatic failover ensures there is no downtime in case of a zone or instance failure on AWS--which sounds like a good scenario.
SoftNAS came up as an option in some other forums--but I'm still looking for responses about it. Does anyone here have experience with SoftNAS--specifically, is it easy to use?