With the advent of the IP Gigabit networks, the performance standards to transport SCSI commands in between Central storage and application servers have increased dynamically. The disk drives on a storage area network are represented as local disks on physical server hardware, to the server applications on an Ethernet Network.
iSCSI offers data transfers over intranets, and is much useful to manage storage solutions, located far off. The Storage Area Network or the SAN will be revolutionized with the inclusion of iSCSI technology, as it offers great scope for increasing the performance and speed of data storage communication. Since IP networks offer ubiquity (omnipresent), the data transmit can not only take place in between the Local Area Networks (LAN), but also in between Metro Area Networks (MAN's) or Wide Area Networks (WANs).
Working of iSCSI
As soon as a user sends a request for an application, the operating system, residing in the computer machine generates the request for the particular data and the apt SCSI command. The amalgamation of the SCSI commands and the data request are encapsulated (summarized) and encrypted, if necessary. Then the IP packet is pre-linked with a packet header and is transmitted over the Ethernet. It is decrypted, as soon as the packet is delivered to the desired system and disassembled, and the SCSI commands are split up from the request. The SCSI controller, bags the SCSI commands and from there, the SCSI commands is stored in the device meant for SCSI storage. Since, there is two-way linking in iSCSI; the protocol thus can be used to revisit the data, of the original request.
In simple words, iSCSI is one of the options, to store data transmissions, over Internet Protocol networks. The other one is through, Fibre Channel over IP which is an elongation of FCIP. In FCIP, the fibre channel control codes plus the data into IP packets for transmission between geographically distant Fibre Channel Storage Area Networks. FCIP is used for concurrence with the Fiber Channel Technology and is available over the in place Ethernet backed networks.
These Products use ISCSI Technology
Uses of iSCSI
If a user is using storage area network, than ISCSI can be more beneficial than Fiber Channel. Below are some of the summarized points: