IBM V7000 Introduction And Implementation Manual page 93

A pure SCSI architecture is based on the client/server model. A client (for example, server or
workstation) initiates read or write requests for data from a target server (for example, a data
storage system).
Commands, which are sent by the client and processed by the server, are put into the
Command Descriptor Block (CDB). The server runs a command, and completion is indicated
by a special signal alert.
The major functions of iSCSI include encapsulation and the
transactions between initiators and targets through the Internet Protocol network, especially
over a potentially unreliable IP network.
The concepts of names and addresses have been carefully separated in iSCSI:
iSCSI name
An is a location-independent, permanent identifier for an iSCSI node. An
iSCSI node has one iSCSI name, which stays constant for the life of the node. The terms
initiator name target name
and
iSCSI address
An specifies not only the iSCSI name of an iSCSI node, but also a location
of that node. The address consists of a host name or IP address, a TCP port number (for
the target), and the iSCSI name of the node. An iSCSI node can have any number of
addresses, which can change at any time, particularly if they are assigned by way of
Dynamic Host Configuration Protocol (DHCP). An IBM Flex System V7000 Storage Node
control canister represents an iSCSI node and provides statically allocated IP addresses.
Each iSCSI node, that is, an initiator or target, has a unique iSCSI Qualified Name (IQN),
which can have a size of up to 255 bytes. The IQN is formed according to the rules adopted
for Internet nodes.
The iSCSI qualified name format defined in RFC3720 contains these elements (in order):
The string "iqn".
A date code specifying the year and month in which the organization registered the
domain or subdomain name used as the naming authority string.
The organizational naming authority string, which consists of a valid, reversed domain or a
subdomain name.
Optionally, a colon (:), followed by a string of the assigning organization's choosing, which
must make each assigned iSCSI name unique.
For IBM Flex System V7000 Storage Node the IQN for its iSCSI target is specified as:
iqn.1986-03.com.ibm:2145.<clustername>.<nodename>
On a Windows server, the IQN, that is, the name for the iSCSI initiator, can be defined as:
iqn.1991-05.com.microsoft:<computer name>
The IQNs can be abbreviated by using a descriptive name, known as an
be assigned to an initiator or a target. The alias is independent of the name and does not
need to be unique. Because it is not unique, the alias must be used in a purely informational
way. It cannot be used to specify a target at login or used during authentication. Both targets
and initiators can have aliases.
An iSCSI name provides the correct identification of an iSCSI device irrespective of its
physical location. Remember that the IQN is an
also refer to an iSCSI name.
identifier
Chapter 2. Introduction to IBM Flex System V7000 Storage Node
reliable delivery
of CDB
alias
. An alias can
address
, not an .
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