It is a highly critical datacenter (healthcare systems with critical patients at the other end of the wire) splitted on two sites (10 minutes by car)
Two sites but one network, I have full layer 2 continuity between the sites, over two physical path.
Sites are in active/active mode :
same network
servers (physical or vsphere VM) are in active/active or active/passive failover
SANs (mostly VMware datastores) are replicated with on-the-fly failover(datacore) over 8gb/s fiberchannel links (two fabrics per site, two physical path)
Internet and mpls access are provided through optic fiber with layer 2 continuity/failover (plus copper backup) between the sites. Internet peering is also secured with BGP failover over another ISP (copper + fiber).
At this moment I have only one firewall per site, I'm thinking of how to have two firewall per site.