3.6 Assumptions for IP-Based SANs
Because it is probable that legacy SCSI, Fibre Channel, and IP-based SANs will coexist for some time, the adoption rate of IP storage solutions will depend on the ability of vendors to supply stable, interoperable, and high-performance products that can accommodate a variety of storage network interfaces.
As the first-generation storage network infrastructure, Fibre Channel has set expectations in terms of storage performance and network flexibility. Although management and interoperability of fabrics may be problematic, stability and performance have at least been achieved for Fibre Channel interfaces on end devices. The onus is therefore on IP storage vendors to accommodate these devices and to ensure the same level of reliability and interoperability for native IP storage interfaces.
Block storage data over IP and Gigabit Ethernet must provide performance equal to or greater than other storage solutions. This is facilitated by functionality inherent in Gigabit Ethernet, including faster transmission speeds (going to 10Gb), link-layer flow control, and link aggregation.
IP storage must also provide enhancements for storage transport unavailable by other means. The more flexible capabilities of VLANs over Gigabit Ethernet and traffic priorization give storage administrators new tools for securing mission-critical transactions in the SAN and for sharing the SAN infrastructure between disparate storage applications.
In terms of management, IP-based SANs benefit from the much wider deployment of sophisticated transport management platforms for enterprise data networks. The merger of storage and networking, however, creates unique requirements beyond network transport management. The integration of network management with storage management is still required to simplify the configuration and management of the SAN, and to reduce administrative overhead.
In terms of interoperability, the greater stability of Fibre Channel end devices and demonstrated interoperability between Gigabit Ethernet switches presents opportunities to combine the best from both worlds to facilitate IP SANs. Native IP storage devices, however, also have to demonstrate both standards compliance and interoperability to achieve acceptance in the market.