• In FC SAN transfer of block level data takes place over Fiber Channel Emerging technologies provide for the transfer of block-level data over an existing IP network infrastructure.

• IP is being positioned as a storage transport because:

  • Easier management

  • Existing network infrastructure can be leveraged

  • Reduced cost compared to new SAN hardware and software

  • Supports multi-vendor interoperability

  • Many long-distance disaster recovery solutions already leverage IP-based networks

  • Many robust and mature security options are available for IP networks

    

IP SAN IMPLEMENTATION

ISCSI

1) IP based protocol used to connect host and storage

2)Carries block-level data over IP-based network

3)Encapsulate SCSI commands and transport as TCP/IP packet

Components of iSCSI

• iSCSI host initiators

  • Host computer using a NIC or iSCSI HBA to connect to storage.

  • iSCSI initiator software may need to be installed.

• iSCSI targets

  • Storage array with embedded iSCSI capable network port.

  • FC-iSCSI Bridge.

• LAN for IP storage network

  - Interconnected Ethernet switches and/or routers.

FCIP

• FCIP is an IP-based storage networking technology

• Combines advantages of Fibre Channel and IP

• Creates virtual FC links that connect devices in a different fabric

• FCIP is a distance extension solution

  • Used for data sharing over geographically dispersed SAN

• Encapsulates FC frames in IP packets

  • FCIP Router is used for encapsulation

  • FC Router at other end removes IP wrapper and sends FC data to other fabric

• Includes security, data integrity, congestion and performance specifications

  

Implementation of IP SAN As iSCSI:

iSCSI is the host-based encapsulation of SCSI I/O over IP using an Ethernet NIC card or an iSCSI HBA in the host. As illustrated in Figure (a), IP traffic is routed over a network either to a gateway device that extracts the SCSI I/O from the IP packets or to an iSCSI storage array. The gateway can then send the SCSI I/O to an FC-based external storage array, whereas an iSCSI storage array can handle the extraction and I/O natively.FCIP uses a pair of bridges (FCIP gateways) communicating over TCP/IP as the transport protocol. FCIP is used to extend FC networks over distances and/or an existing IP-based infrastructure, as illustrated in Figure (b).

Today, iSCSI is widely adopted for connecting servers to storage because it is relatively inexpensive and easy to implement, especially in environments where an FC SAN does not exist. FCIP is extensively used in disaster-recovery implementations, where data is duplicated on disk or tape to an alternate site.

Applications Of iSCSI iSCSI enables the transport of block-level storage traffic over IP networks. It builds on two widely used technologies — SCSI commands for storage and IP protocols for networking iSCSI is an end-to-end protocol for transporting storage I/O block data over an IP network. The protocol is used on servers (initiators), storage devices (targets), and protocol transfer gateway devices iSCSI storage solutions are being deployed primarily in environments dominated by midrange and low-end servers. These classes of servers are most likely to be Intel-architecture servers running Windows, NetWare, or Linux, although solutions for small RISC servers running Unix are now starting to emerge. The applications here are typically business-critical at the departmental level, though there are mission-critical applications for smaller enterprises on these servers.

FCIP Implementation

Implementation of IP SAN as FCIP:

FCIP uses a pair of bridges (FCIP gateways) communicating over TCP/IP as the transport protocol.

FCIP is used to extend FC networks over distances and/or an existing IP-based infrastructure, as illustrated in Figure (b).

FCIP is extensively used in disaster-recovery implementations, where data is duplicated on disk or tape to an alternate site Fibre Channel over IP (FCIP or FC/IP, also known as Fibre Channel tunneling or storage tunneling) is an Internet Protocol (IP)-based storage networking technology developed by the Internet Engineering Task Force (IETF).

FCIP mechanisms enable the transmission of Fibre Channel (FC) information by tunneling data between storage area network (SAN) facilities over IP networks; this capacity facilitates data sharing over a geographically distributed enterprise. One of two main approaches to storage data transmission over IP networks, FCIP is among the key technologies expected to help bring about rapid development of the storage area network market by increasing the capabilities and performance of storage data transmission.

Applications of FCIP

Asynchronous data replication—Enables low recovery point objective (RPO) applications between intelligent storage arrays using proprietary replication software. Network latency does not affect application performance the way it does with synchronous replication. You may need to tune the replication software or upper-layer protocol to ensure optimum use of the FCIP link.

Remote tape vaulting—enables remote backup for disaster recovery using tape or disk. Tape applications typically allow a single outstanding I/O operation, which limits throughput on long distance links. Write Acceleration and optionally compression techniques can help to optimize throughput in these situations. Host initiator to remote pooled storage—Enables access to FC-attached pooled storage arrays in another site or data center.