Internet Small Computer Systems Interface
Internet Small Computer Systems Interface (iSCSI) is a storage networking protocol that enables the transmission of SCSI commands and data over an IP-based network. It allows computers and servers to connect to and access storage devices such as hard disk drives and solid-state drives over a TCP/IP network, including local area networks (LANs), wide area networks (WANs), and the internet.
Here are some key points about iSCSI:
- Storage Networking: iSCSI enables the creation of storage area networks (SANs) using existing IP networks. It allows for the consolidation of storage resources and centralization of storage management, providing a scalable and cost-effective solution for data storage.
- SCSI Protocol: iSCSI encapsulates SCSI commands and data into TCP/IP packets, allowing SCSI-based storage devices to be accessed over IP networks. It utilizes the familiar SCSI command set, which is widely used in traditional storage systems.
- Block-Level Storage: iSCSI operates at the block level, treating storage devices as logical block addressable devices. This allows for the efficient transfer of data in blocks, providing high-performance storage access.
- Initiators and Targets: In an iSCSI setup, the device or system initiating the storage request is called the initiator, while the device or system providing the storage resources is called the target. Initiators can be servers or client systems, while targets are typically storage devices or storage arrays.
- iSCSI Name: Each iSCSI initiator and target is identified by a unique iSCSI name, known as an iSCSI Qualified Name (IQN). The IQN consists of a naming convention that includes the target’s domain, optional subdomains, and unique identifier.
- Transport Options: iSCSI can use different transport options, including TCP/IP and Internet Fibre Channel Protocol (iFCP). TCP/IP is the most commonly used transport protocol for iSCSI, providing reliable and widely supported communication over IP networks.
- Security Features: iSCSI supports various security features, such as CHAP (Challenge-Handshake Authentication Protocol) authentication and IPsec (IP Security) encryption, to ensure the integrity, confidentiality, and authentication of data transferred between initiators and targets.
- Compatibility: iSCSI is compatible with existing Ethernet networks, leveraging the widespread availability and cost-effectiveness of IP-based infrastructure. It can operate over standard Ethernet switches and routers without the need for dedicated storage networking equipment.
iSCSI offers a flexible and scalable storage solution that leverages existing IP networks. It provides a cost-effective alternative to traditional Fibre Channel-based storage networks, making it an attractive option for organizations of all sizes. By utilizing iSCSI, businesses can centralize storage resources, simplify storage management, and improve data accessibility and availability.