What is there to note regarding SAN/NAS Support?

If the disks are represented as block devices on the machine, as most SAN are, Elastic Disaster Recovery will replicate them transparently, just like actual local disks.

If the disks are mounted over the network, such as an NFS share, as most NAS implementations are, the AWS Replication Agent would need to be installed on the actual NFS server in order to replicate the disk.