Chapter 1. Disk attachment technology
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Draft Document for Review August 30, 2007 12:59 am
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Figure 1-3 iSCSI components
The iSCSI initiator can be either an iSCSI HBA inside a host server, or you can define a
software iSCSI initiator by using an iSCSI stack and an Ethernet network adapter. An
example of an iSCSI stack is the Microsoft iSCSI Software Initiator, which runs on Windows
2000, Windows Server® 2003 and Windows XP. At the time of writing, the current version is
v2.04 and is available for download from the Microsoft Web site.
iSCSI HBAs are physically very similar to Ethernet network cards. However, they typically
contain a ROM-based BIOS utility which can be used to configure the iSCSI settings and
HBA operational parameters. In this respect, they resemble SCSI and FC HBAs. Inside the
operating system, the iSCSI HBAs are classified as storage adapters.
The iSCSI target is typically the storage device or subsystem, for example DS3300. Other
types of peripheral devices, like tape drives and medium changers, can act as iSCSI targets
as well.
iSCSI naming
The iSCSI initiators and targets on a SAN are known by their respective iSCSI names, which
must be unique. the iSCSI name is used as part of an ISCSI address, as part of all sessions
established between initiators and targets. There are two types of iSCSI names
IQN
A commonly used format of iSCSI names is the
iSCSI Qualified Name
(IQN). The format of
an IQN is:
iqn.yyyy-mm.{reversed domain name}
For example, an iSCSI HBA inside a host server named Rhine in the domain rivers.local
would be assigned the following IQN:
iqn.2007-06.local.rivers.rhine
SCSI (Block I/O) Protocol
Client Desktop
Application Server
IP
Initiator
Initiator
iSCSI device
discovery
Target
