WiebeTech LLC
R T X - I R U s e r ’ s M a n u a l
- 6 -
Chapter 2: Introduction to iSCSI
2.1 What is iSCSI?
iSCSI is a technology that allows a data storage device to be accessed over a TCP/IP network using
SCSI protocols. When your computer’s OS receives a request for data access, it generates a SCSI
command and then sends an IP packet across a network or direct ethernet connection. A software utility
known as an iSCSI Initiator is used to generate the SCSI commands. Such a utility must be installed on
the computer before it can access an iSCSI storage device.
2.2 What is the benefit of iSCSI?
An iSCSI storage device can be placed anywhere throughout a network, so the device can reside at a
great distance from the computer which accesses it. It is also a very fast connection when used on a
gigabit network, achieving speeds of 100MB/sec or more. The connection it uses (RJ45 – standard
ethernet port) is commonly found on desktop and laptop computers, so there is no need to purchase
potentially expensive host bus adapters to provide a connection.
2.3 What is iSCSI not?
iSCSI storage devices are not Network Attached Storage (NAS) devices. They have no built-in server
capabilities and therefore cannot be accessed by more than one computer at a time. Multiple computers
can only access the data if the iSCSI device is first attached to a single computer which is then set up as
a server.
