The lab for the 160 class uses iSCSI to connect to a server that functions as a storage server.   This is a pretty good explanation of the difference between a NAS (like our FreeNAS server in class) and a SAN.  


Understanding iSCSIInternet Small Computer System Interface (iSCSI) is a protocol that defines how data can be transferred between host systems (such as servers) and storage devices (such as storage area networks or SANs). iSCSI was standardized by the IETF in 2003 and combines the Small Computer System Interface (SCSI) storage protocol with the TCP/IP protocol suite to define a mechanism for block transfer of data over Ethernet networks.iSCSI enables the transmission of SCSI block storage commands within IP packets while allowing TCP to handle flow control and ensure reliable transmission. Block storage is how SANs communicate with applications running on host systems. Data is transferred block by block in raw form between the SAN and the host system. In effect, this makes the storage on the SAN appear to the host system as if it was direct attached storage (DAS) and not network storage. The host system can create instances of disk storage called virtual disks (also called logical unit numbers or LUNs, but essentially just VHD files) within the storage array, create volumes on these virtual disks, format the volumes using a file system like NTFS, and use these volumes as if they were locally installed hard drives in the host system. In contrast to this, a network attached storage (NAS) device uses a file transfer protocol such as SMB, CIFS or NFS to transfer data between the host system and the NAS device.