6.5.1

Table Of Contents
Generally, a single path from a host to a LUN consists of an iSCSI adapter or NIC, switch ports,
connecting cables, and the storage controller port. If any component of the path fails, the host selects
another available path for I/O. The process of detecting a failed path and switching to another is called
path failover.
For more information on multipathing, see Chapter 18 Understanding Multipathing and Failover.
Ports in the iSCSI SAN
A single discoverable entity on the iSCSI SAN, such as an initiator or a target, represents an iSCSI node.
Each node has one or more ports that connect it to the SAN.
iSCSI ports are end-points of an iSCSI session. Each node can be identified in a number of ways.
IP Address Each iSCSI node can have an IP address associated with it so that routing
and switching equipment on your network can establish the connection
between the server and storage. This address is just like the IP address
that you assign to your computer to get access to your company's network
or the Internet.
iSCSI Name A worldwide unique name for identifying the node. iSCSI uses the iSCSI
Qualified Name (IQN) and Extended Unique Identifier (EUI).
By default, ESXi generates unique iSCSI names for your iSCSI initiators,
for example, iqn.1998-01.com.vmware:iscsitestox-68158ef2.
Usually, you do not have to change the default value, but if you do, make
sure that the new iSCSI name you enter is worldwide unique.
iSCSI Alias A more manageable name for an iSCSI device or port used instead of the
iSCSI name. iSCSI aliases are not unique and are intended to be just a
friendly name to associate with a port.
iSCSI Naming Conventions
iSCSI uses a special unique name to identify an iSCSI node, either target or initiator.
iSCSI names are formatted in two different ways. The most common is the IQN format.
For more details on iSCSI naming requirements and string profiles, see RFC 3721 and RFC 3722 on the
IETF website.
iSCSI Qualified Name Format
The iSCSI Qualified Name (IQN) format takes the form iqn.yyyy-mm.naming-authority:unique
name, where:
n
yyyy-mm is the year and month when the naming authority was established.
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