Which protocol uses IP networks to enable servers to access remote disks as if they were locally attached?

Which protocol uses IP networks to enable servers to access remote disks as if they were locally attached?

• A. SAS
• B. SATA
• C. iSCSI
• D. Fibre Channel

Answer: (C)

This question is about how storage can be accessed over an IP network so that a remote disk appears as a locally attached device. iSCSI does exactly this: it sends SCSI commands over TCP/IP, allowing a server to access a remote storage array’s disks as if they were local block devices. The server’s iSCSI initiator connects to an iSCSI target presenting LUNs, which the OS sees as local disks that can be formatted and mounted just like directly attached storage. This enables a SAN over existing Ethernet networks, offering cost-effective scalability. SAS and SATA are direct-attached storage interfaces and aren’t designed to traverse IP networks. Fibre Channel is a separate SAN protocol with its own network, not IP-based by default (though there are tunneling methods to carry FC over IP in some setups). The standard approach for IP-based remote disk access is iSCSI, making it the best choice here.

This question is about how storage can be accessed over an IP network so that a remote disk appears as a locally attached device. iSCSI does exactly this: it sends SCSI commands over TCP/IP, allowing a server to access a remote storage array’s disks as if they were local block devices. The server’s iSCSI initiator connects to an iSCSI target presenting LUNs, which the OS sees as local disks that can be formatted and mounted just like directly attached storage. This enables a SAN over existing Ethernet networks, offering cost-effective scalability.

SAS and SATA are direct-attached storage interfaces and aren’t designed to traverse IP networks. Fibre Channel is a separate SAN protocol with its own network, not IP-based by default (though there are tunneling methods to carry FC over IP in some setups). The standard approach for IP-based remote disk access is iSCSI, making it the best choice here.