We've recently re-engineered an IP storage network for a client.
This involved tearing down the legacy storage network and implementing new VLANs on new Cisco switches. The implementation has allowed for introduction of correct iSCSI multi-pathing for VMware vSphere, and proper protocol segmentation for performance and security.
What was particularly challenging in this instance was to find a design that supported multiple storage systems; we accommodated Dell EqualLogic PS arrays in two server rooms (with replication), NetApp storage with iSCSI and NFS protocols (as well as CIFS shares to the LAN), a Dell MD3000i iSCSI appliance, a Drobo and a native Linux NFS server.
After a long weekend that also included extensive re-engineering of the ESX host server networking configurations, all systems were up and running, EqualLogic replication was functioning, VMware Site Recovery manager was revisited and configuration verified, and best of all, security, stability and performance were improved.