Fabric Configuration Guide, Cisco DCNM for SAN, Release 5.x
Discovering SCSI Targets
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Discovering SCSI Targets

Table Of Contents

Discovering SCSI Targets

Information About SCSI LUN Discovery

About Starting SCSI LUN Discovery

About Initiating Customized Discovery

Licensing Requirements for SCSI

Discovering SCSI Targets

Starting SCSI LUN Discovery

Initiating Customized Discovery

Verifying SCSI Targets Configuration

Displaying SCSI LUN Information

Field Descriptions for SCSI Targets

iSCSI Connection

iSCSI Initiators

iSCSI Targets

iSCSI Session Initiators

iSCSI Global

iSCSI Session Statistics

iSCSI iSLB VRRP

iSCSI Initiator Access

iSCSI Initiator PWWN

iSCSI Sessions

iSCSI Sessions Detail

Additional References

Related Document

Standards

RFCs

MIBs


Discovering SCSI Targets


This chapter describes the SCSI LUN discovery feature provided in switches in the Cisco MDS 9000 Family. It includes the following sections:

Information About SCSI LUN Discovery

Licensing Requirements for SCSI

Discovering SCSI Targets

Verifying SCSI Targets Configuration

Field Descriptions for SCSI Targets

Additional References

Information About SCSI LUN Discovery

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.

This section includes the following topics:

About Starting SCSI LUN Discovery

About Initiating Customized Discovery

About Starting SCSI LUN Discovery

SCSI LUN discovery is done on demand.

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:

Feature
License Requirement

ENTERPRISE_PKG

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.

FM_SERVER_PKG

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.


Discovering SCSI Targets

This section includes the following topics:

Starting SCSI LUN Discovery

Initiating Customized Discovery

Starting SCSI LUN Discovery

Detailed Steps

To begin SCSI LUN discovery using Device Manager, follow these steps:


Step 1 Choose FC > Advanced > LUNs.

You see the LUN Configuration dialog box.

Step 2 Set StartDiscovery to local, remote or both.

Step 3 Choose the DiscoveryType and OS.

Step 4 Click Apply to begin discovery.


Initiating Customized Discovery

Detailed Steps

To initiate a customized discovery using Device Manager, follow these steps:


Step 1 From the VSAN drop-down menu, select the VSAN in which you want to initiate a customized discovery.

Step 2 Click FC > Advanced > LUNs.

You see the LUN Configuration dialog box.

Step 3 Set StartDiscovery to local, remote or both.

Step 4 Fill in the DiscoveryType and OS fields.

Step 5 Click Apply to begin discovery.


Verifying SCSI Targets Configuration

For detailed information about the fields in the output from these commands, refer to the Cisco MDS 9000 Family Command Reference.

Displaying SCSI LUN Information

Displaying SCSI LUN Information

To display the results of the discovery using Device Manager, follow these steps:


Step 1 Choose FC > Advanced > LUNs

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.

iSCSI Connection

Field
Description

LocalAddr

The local Internet network address used by this connection.

RemoteAddr

The remote Internet network address used by this connection.

CID

The iSCSI connection ID for this connection.

State

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.

MaxRecvDSLen

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.

SendMarker

Indicates whether or not this connection is inserting markers in its outgoing data stream.

HeaderDigest

The iSCSI header digest scheme in use within this connection.

DataDigest

The iSCSI data digest scheme in use within this connection.


iSCSI Initiators

Field
Description

Name or IP Address

A character string that is a globally unique identifier for the node represented by this entry.

VSAN Membership

The list of configured VSANs the node represented by this entry can access.

Dynamic

If true, then the node represented by this entry is automatically discovered.

Initiator Type

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.

Node WWN

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.

Port WWN

All the FC port addresses associated with this node.

AuthUser

This is the only CHAP user name that the initiator is allowed to log in with.

Target UserName

(Optional) The user name to be used for login. If you do not supply a username, the global user name is used.

Target Password

(Optional) The password to be used for login. If you do not supply a password, the global password is used.

Load Metric

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.


iSCSI Targets

Field
Description

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.

iSCSI Name

The iSCSI name of the node represented by this entry.

Dynamic

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.

Advertised Interfaces

Lists all the interfaces on which the target could be advertised.

Trespass Mode

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.

RevertToPrimaryPort

Indicates if it is required to revert back to primary port if the FC target comes back online.


iSCSI Session Initiators

Field
Description

Name or IP Address

The name or IP address of the initiator port.

Alias

The initiator alias acquired at login.


iSCSI Global

Field
Description

AuthMethod

The authentication method.

InitiatorIdleTimeout

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.

iSLB ZonesetActivate

Checking this option performs automatic zoning associated with the initiator targets

DynamicInitiator

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.

Target UserName

The default user name used for login. If an initiator user name is specified, that user name is used instead.

Target Password

The default password used for login. If an initiator password is specified, that password is used instead.


iSCSI Session Statistics

Field
Description

PDU Command

The count of Command PDUs transferred on this session.

PDU Response

The count of Response PDUs transferred on this session.

Data Tx

The count of data bytes that were transmitted by the local iSCSI node on this session.

Data Rx

The count of data bytes that were received by the local iSCSI node on this session.

Errors Digest

Authentication errors.

Errors CxnTimeout

Connection timeouts.


iSCSI iSLB VRRP

Field
Description

VrId, IpVersion

The virtual router number and the IP version (IPv4, IPv6, or DNS).

Load Balance

Indicates whether load balancing is enabled.


iSCSI Initiator Access

Field
Description

Initiator Name

The iSCSI node name.


iSCSI Initiator PWWN

Field
Description

Port WWN

The FC address for this entry.


iSCSI Sessions

Field
Description

Type

Type of iSCSI session:

normal—Session is a normal iSCSI session

discovery—Session is being used only for discovery.

TargetName

If Direction is Outbound, this will contain the name of the remote target.

Vsan ID

The VSAN to which this session belongs to.

ISID

The initiator-defined portion of the iSCSI session ID.

TSIH

The target-defined identification handle for this session.


iSCSI Sessions Detail

Field
Description

ConnectionNumber

The number of transport protocol connections that currently belong to this session.

ImmediateData

Whether the initiator and target have agreed to support immediate data on this session.

Initial

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.

MaxOutstanding

The maximum number of outstanding Ready-To-Transfers per task within this session.

First

The maximum length supported for unsolicited data sent within this session.

Max

The maximum number of bytes which can be sent within a single sequence of Data-In or Data-Out PDUs.

Sequence

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.

PDU

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.


Additional References

For additional information related to implementing VSANs, see the following section:

Related Document

Standards

RFCs

MIBs

Related Document

Related Topic
Document Title

Cisco MDS 9000 Family Command Reference

Cisco MDS 9000 Family Command Reference


Standards

Standard
Title

No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.

-


RFCs

RFC
Title

No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified.

-


MIBs

MIBs
MIBs Link

CISCO-SCSI-FLOW-MIB

CISCO-SCSI-MIB

To locate and download MIBs, go to the following URL:

http://www.cisco.com/en/US/products/ps5989/prod_technical_reference_list.html