iSCSI

iSCSI (Internet Small Computer Systems Interface) is a network protocol standard that allows the use of the SCSI Protocol over TCP/IP networks. It enables the transfer of data over intranets and the management of storage over long distances.

iSCSI is used to facilitate data transfers over Local Area Networks (LANs), Wide Area Network (WANs), or the internet, and can enable location-independent data storage and retrieval.

iSCSI encapsulates SCSI commands into TCP/IP packets, which are then transmitted over LANs, WANs, or the internet. Unlike file-based storage (such as Network File Share or Server Message Block/CIFS), iSCSI works at the block level, allowing it to interact more closely with the storage devices, which is useful for tasks like disk partitioning.

iSCSI can be implemented over existing network infrastructure, eliminating the need for expensive dedicated storage networks like Fibre Channel. iSCSI allows computers to boot from remote storage, which is useful for centralized management and for stateless computers or thin clients. It is commonly used in SANs for linking data storage facilities.

This is how it works:

• iSCSI Initiator: A client, such as a server, that sends SCSI commands. This initiator communicates over the network with the iSCSI target.
• iSCSI Target: The storage resource, which could be a dedicated storage server or storage hardware, receives and responds to the commands from the initiator.

Since iSCSI relies on network performance, its efficiency can be impacted by network congestion, latency, and reliability. When used over public networks, iSCSI traffic should be secured using techniques like Virtual Private Networks or IPsec to prevent unauthorized access. Proper configuration of network settings and iSCSI parameters is essential to ensure optimal performance and compatibility with various storage devices.