iSCSI Introduction
iSCSI, an industry standard storage protocol defined and maintained by the Internet Engineering Task Force, enables the consolidation, scalability, and management advantages of a storage area network (SAN) without the unfamiliarity, complexity, and expense of traditional SAN interconnects. Also known as Internet SCSI, iSCSI encapsulates SCSI block storage commands into Ethernet packets for transport over IP networks, enabling companies to leverage standard, familiar Ethernet networking infrastructures to create affordable SANs.
An iSCSI SAN may be the perfect choice for companies interested in making the move from direct attached to networked storage. Using the same block-level SCSI commands as traditional server-attached storage, iSCSI storage networks are fully compatible with existing server software such as file systems, databases, and applications. Similarly, since iSCSI runs on ubiquitous and familiar IP networks, there is no need to deploy a new networking infrastructure or retrain staff to realize the benefits of a SAN.
Unlike direct-attached storage, iSCSI storage solutions enable you to share storage resources across servers, easily expand storage capacity without taking critical applications offline, and consolidate your data protection processes and operations for improved data availability at significant administrative cost savings.
In its simplest form, an iSCSI-based SAN (IP SAN) solution consists of servers equipped with either standard Gigabit Ethernet network interface cards and iSCSI "initiator" software or iSCSI host bus adapter cards and driver software. Cards are connected via an Ethernet switch to a native iSCSI storage system using standard Ethernet cables. The networked storage pool appears to each of the servers to be dedicated local disk storage.
The iSCSI protocol was designed with the appropriate security options to enable the creation of SANs over a wide range of network topologies—from private IP-based subnets to data center or departmental local area networks (LANs) and wide area networks (WANs).
iSCSI-based SAN solutions are an excellent choice for storage consolidation in low-cost and Intel® architecture server environments and are particularly attractive in departmental, regional, or remote data centers where Fibre Channel solutions have not historically offered a cost-effective option. iSCSI also provides highly affordable secondary storage or data protection solutions for corporate data centers.
Current deployments of iSCSI span a broad range of industries and IT environments.
Benefits
- Significant cost savings. iSCSI SAN storage solutions leverage the volume economics, scalability, and simplicity of standard Ethernet networking.
- Investment protection. iSCSI enables you to leverage your existing Ethernet networking investment and expertise to deploy either departmental SANs that complement your existing Fibre Channel data center SAN or "green field" SANs within a distributed IT environment.
- Proven technology. iSCSI brings together two of the most ubiquitous and well-understood technologies in the IT industry—SCSI storage and IP networks.