Small Computer System Interface (SCSI) targets include disks, tapes, and other storage devices. These targets do not register logical unit numbers (LUNs) with the name server.
The name server requires LUN information for the following reasons:
To display LUN storage device information so an NMS can access this information.
To report device capacity, serial number, and device ID information.
To register the initiator and target features with the name server.
The SCSI LUN discovery feature uses the local domain controller Fibre Channel address. It uses the local domain controller as the source FC ID, and performs SCSI INQUIRY, REPORT LUNS, and READ CAPACITY commands on SCSI devices.
The SCSI LUN discovery feature is initiated on demand, through CLI or SNMP. This information is also synchronized with neighboring switches, if those switches belong to the Cisco MDS 9000 Family.
Only Nx ports that are present in the name server database and that are registered as FC4 Type = SCSI_FCP are discovered.
About Initiating Customized Discovery
Customized discovery consists of a list of VSAN and domain pairs that are selectively configured to initiate a discovery. The domain ID is a number from 0 to 255 in decimal or a number from 0x0 to 0xFF in hex.
Licensing Requirements for SCSI
The following table shows the licensing requirements for this feature:
The enterprise license is required to enable the SCSI flow statistics. For a complete explanation of the licensing scheme, see the Cisco MDS 9000 Family NX-OS Licensing Guide.
The Cisco DCNM for SAN Package is required to enable the traffic analyzer for SCSI flow statistics. For a complete explanation of the licensing scheme, see the Cisco MDS 9000 Family NX-OS Licensing Guide.
To display the results of the discovery using Device Manager, follow these steps:
Step 1 Choose FC > Advanced > LUN s
You see the LUN Configuration dialog box.
Step 2 Click the LUN tab or the Targets tab.
Field Descriptions for SCSI Targets
The following are the field descriptions for SCSI targets.
The local Internet network address used by this connection.
The remote Internet network address used by this connection.
The iSCSI connection ID for this connection.
The current state of this connection, from an iSCSI negotiation point of view.
login— The transport protocol connection has been established, but a valid iSCSI login response with the final bit set has not been sent or received.
full—A valid iSCSI login response with the final bit set has been sent or received.
logout— A valid iSCSI logout command has been sent or received, but the transport protocol connection has not yet been closed.
The maximum data payload size supported for command or data PDUs in use within this connection. The size is reported in bytes even though the negotiation is in 512K blocks.
Indicates whether or not this connection is inserting markers in its outgoing data stream.
The iSCSI header digest scheme in use within this connection.
The iSCSI data digest scheme in use within this connection.
Name or IP Address
A character string that is a globally unique identifier for the node represented by this entry.
The list of configured VSANs the node represented by this entry can access.
If true, then the node represented by this entry is automatically discovered.
Indicates whether the node is a host that participates in iSCSI load-balancing.
Persistent Node WWN
If true, then the same FC address is assigned to the node if it were to be represented again in the FC domain with the same node name. Note that the node FC address is either automatically assigned or manually configured.
SystemAssigned Node WWNN
If true, the FC address is automatically assigned to this node. If false, then the FC address has to be configured manually.
The persistent FC address of the node.
Persistent Port WWN
If true, then the same FC address is assigned to the ports of the node if it were to be represented again in the FC domain with the same node name.
All the FC port addresses associated with this node.
This is the only CHAP user name that the initiator is allowed to log in with.
(Optional) The user name to be used for login. If you do not supply a username, the global user name is used.
(Optional) The password to be used for login. If you do not supply a password, the global password is used.
A configured load metric of this iSCSI initiator for the purpose of iSCSI load balancing.
Auto Zone Name
The zone name that is used when the system creates automatic zone for this initiator's specific list of targets.
Dynamically Import FC Targets
Check this option to dynamically import FC targets into the iSCSI domain. A target is not imported if it already exists in the iSCSI domain.
The iSCSI name of the node represented by this entry.
Indicates if the node represented by this entry was either automatically discovered or configured manually.
Primary Port WWN
The FC address for this target.
Secondary Port WWN
The optional secondary FC address for this target. This is the FC address used if the primary cannot be reached.
LUN Map iSCSI
The configured default logical unit number of this LU.
LUN Map FC Primary
The logical unit number of the remote LU for the primary port address.
LUN Map FC Secondary
The logical unit number of the remote LU for the secondary port address.
Initiator Access All
If true, then all the initiators can access this target even those which are not in the initiator permit list of this target. If false, then only initiators which are in the permit list are allowed access to this target.
Initiator Access List
Lists all the iSCSI nodes that are permitted to access the node represented by this entry. If AllAllowed is false and the value of List is empty, then no initiators are allowed to access this target.
Lists all the interfaces on which the target could be advertised.
The trespass mode for this node. Every iSCSI target represents one or more port(s) on the FC target. If true, the node instructs the FC node to present all LUN I/O requests to secondary port if the primary port is down.
Indicates if it is required to revert back to primary port if the FC target comes back online.
iSCSI Session Initiators
Name or IP Address
The name or IP address of the initiator port.
The initiator alias acquired at login.
The authentication method.
The time for which the gateway (representing a FC target) waits from the time of last iSCSI session to a iSCSI initiator went down, before purging the information about that iSCSI initiator.
Checking this option performs automatic zoning associated with the initiator targets
This field determines how dynamic iSCSI initiators are created. Selecting the iSCSI option (default) creates dynamic iSCSI initiators. If you select iSLB then the an iSLB dynamic initiator is created. Selecting the deny option does not allow dynamic creation of the initiators.
The default user name used for login. If an initiator user name is specified, that user name is used instead.
The default password used for login. If an initiator password is specified, that password is used instead.
iSCSI Session Statistics
The count of Command PDUs transferred on this session.
The count of Response PDUs transferred on this session.
The count of data bytes that were transmitted by the local iSCSI node on this session.
The count of data bytes that were received by the local iSCSI node on this session.
iSCSI iSLB VRRP
The virtual router number and the IP version (IPv4, IPv6, or DNS).
Indicates whether load balancing is enabled.
iSCSI Initiator Access
The iSCSI node name.
iSCSI Initiator PWWN
The FC address for this entry.
Type of iSCSI session:
normal—Session is a normal iSCSI session
discovery—Session is being used only for discovery.
If Direction is Outbound, this will contain the name of the remote target.
The VSAN to which this session belongs to.
The initiator-defined portion of the iSCSI session ID.
The target-defined identification handle for this session.
iSCSI Sessions Detail
The number of transport protocol connections that currently belong to this session.
Whether the initiator and target have agreed to support immediate data on this session.
If true, the initiator must wait for a Ready-To-Transfer before sending to the target. If false, the initiator may send data immediately, within limits set by FirstBurstSize and the expected data transfer length of the request.
The maximum number of outstanding Ready-To-Transfers per task within this session.
The maximum length supported for unsolicited data sent within this session.
The maximum number of bytes which can be sent within a single sequence of Data-In or Data-Out PDUs.
If false, indicates that iSCSI data PDU sequences may be transferred in any order. If true indicates that data PDU sequences must be transferred using continuously increasing offsets, except during error recovery.
If false, iSCSI data PDUs within sequences may be in any order. If true indicates that data PDUs within sequences must be at continuously increasing addresses, with no gaps or overlay between PDUs.
For additional information related to implementing VSANs, see the following section: