Cisco Nexus 1000V System Management Configuration Guide, Release 4.0(4)SV1(2)
Configuring iSCSI Multipath
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Configuring iSCSI Multipath

Table Of Contents

Configuring iSCSI Multipath

Information About iSCSI Multipath

Guidelines and Limitations

Prerequisites

Default Settings

Configuring a Port Profile for iSCSI Multipath

Additional References

Related Documents

Standards

Feature History for iSCSI Multipath


Configuring iSCSI Multipath


Revised: April 27, 2011, OL-20458-02

This chapter describes how to configure iSCSI multipath for multiple routes between a server and its storage devices.

This chapter includes the following topics:

Information About iSCSI Multipath

Guidelines and Limitations

Prerequisites

Default Settings

Configuring a Port Profile for iSCSI Multipath

Additional References

Feature History for iSCSI Multipath

Information About iSCSI Multipath

The iSCSI multipath feature sets up multiple routes between a server and its storage devices for maintaining a constant connection and balancing the traffic load. The multipathing software handles all input and output requests and passes them through on the best possible path. Traffic from host servers is transported to shared storage using the iSCSI protocol that packages SCSI commands into iSCSI packets and transmits them on the Ethernet network.

If a path or any component along the path fails, the server selects another of the available paths.

Guidelines and Limitations

The following are guidelines and limitations for the iSCSI multipath feature.

The port profile used for iSCSI multipath must be an access port profile. It cannot be a trunk port profile.

The following are required:

A system VLAN created on the Cisco Nexus 1000V.

One of the uplink ports must already have this VLAN in its system VLAN range.

A host configured with one port channel that includes two or more physical NICs.

VMware kernel NICs configured to access the SAN external storage are required.

A Vmware Kernel NIC can only be pinned or assigned to one physical NIC.

A physical NIC can have multiple VMware Kernel NICs pinned or assigned to it.

Prerequisites

The iSCSI Multipath feature has the following prerequisites.

You must understand VMware iSCSI SAN storage virtualization.

You must know how to set up the iSCSI Initiator software on your VMware ESX/ESXi host.

The host is already functioning with the VMware ESX 4.0.1 Update 01 software release.

You must understand iSCSI multipathing and path failover.

Default Settings

Table 13-1 lists the default settings in the iSCSI Multipath configuration.

Table 13-1 iSCSI Multipath Defaults 

Parameter
Default

Type (port-profile)

vEthernet

Description (port-profile)

None

VMware port group name (port-profile)

The name of the port profile

Switchport mode (port-profile)

Access

State (port-profile)

Disabled


Configuring a Port Profile for iSCSI Multipath

Use this section to configure communication multipathing between hosts and targets over iSCSI protocol by assigning the vEthernet interface to an iSCSI multipath port profile configured with a system VLAN.

BEFORE YOU BEGIN

Before starting the procedures in this section you must know or do the following.

You have already configured the host with one port channel that includes two or more physical NICs.

You have already created VMware kernel NICs to access the SAN external storage.

A Vmware Kernel NIC can only be pinned or assigned to one physical NIC.

A physical NIC can have multiple VMware Kernel NICs pinned or assigned to it.

Multipathing must be configured on the interface by using this procedue to create an iSCSI multipath port profile and then assigning the interface to it.

You are logged in to the CLI in EXEC mode.

You know the VLAN ID for the VLAN you are adding to this iSCSI multipath port profile.

The VLAN must already be created on the Cisco Nexus 1000V.

The VLAN that you assign to this iSCSI multipath port profile must be a system VLAN.

One of the uplink ports must already have this VLAN in its system VLAN range.

The port profile must be an access port profile. It cannot be a trunk port profile. This procedure includes steps to configure the port profile as an access port profile.

SUMMARY STEPS

1. config t

2. port-profile type vethernetname

3. vmware port-group [name]

4. switchport mode access

5. switchport access vlan vlanID

6. no shutdown

7. (Optional) system vlan vlanID

8. capability iscsi-multipath

9. state enabled

10. (Optional) show port-profile name

11. (Optional) copy running-config startup-config

DETAILED STEPS

 
Command
Purpose

Step 1 

config t

Example:

n1000v# config t

n1000v(config)#

Places you in the CLI Global Configuration mode.

Step 2 

port-profile type vethernet name

Example:

n1000v(config)# port-profile type vethernet VMK-port-profile

n1000v(config-port-prof)#

Places you into the CLI Port Profile Configuration mode for the specified port profile.

type: Defines the port-profile as Ethernet or vEthernet type. Once configured, this setting cannot be changed. The default is vEthernet type.

Note If a port profile is configured as an Ethernet type, then it cannot be used to configure VMware virtual ports.

name: The port profile name can be up to 80 characters and must be unique for each port profile on the Cisco Nexus 1000V.

Step 3 

description profiledescription


Example:

n1000v(config-port-prof)# description "Port Profile for iSCSI multipath"

n1000v(config-port-prof)#

Adds a description to the port profile. This description is automatically pushed to the vCenter Server.

profile description: up to 80 ASCII characters

Note If the description includes spaces, it must be surrounded by quotations.

Step 4 

vmware port-group [name]

Example:

n1000v(config-port-prof)# vmware port-group VMK-port-profile

n1000v(config-port-prof)#

Designates the port-profile as a VMware port group.

The port profile is mapped to a VMware port group of the same name. When a vCenter Server connection is established, the port group created in Cisco Nexus 1000V is then distributed to the virtual switch on the vCenter Server.

name: The Vmware port group name.If you want to map the port profile to a different port group name, use the alternate name.

Step 5 

switchport mode access ]

Example:

n1000v(config-port-prof)# switchport mode access

n1000v(config-port-prof)#

Designates that the interfaces are switch access ports (the default).

Step 6 

switchport access vlan vlanID

Example:

n1000v(config-port-prof)# switchport access vlan 254

n1000v(config-port-prof)#

Assigns the system VLAN ID to the access port for this port profile.

Note The VLAN assigned to this iSCSI port profile must be a system VLAN.

Step 7 

no shutdown

Example:

n1000v(config-port-prof)# no shutdown

n1000v(config-port-prof)#

Administratively enables all ports in the profile.

Step 8 

system vlan vlanID

Example:

n1000v(config-port-prof)# system vlan 254

n1000v(config-port-prof)#

Adds the system VLAN to this port profile.

This ensures that, when the host is added for the first time or rebooted later, the VEM will be able to reach the VSM. One of the uplink ports must have this VLAN in its system VLAN range.

Step 9 

capability iscsi-multipath

Example:

n1000v(config-port-prof)# capability iscsi-multipath

n1000v(config-port-prof)#

Allows the port to be used for iSCSI multipathing.

In vCenter Server, the iSCSI Multipath port profile must be selected and assigned to the VM kernel NIC port.

Step 10 

state enabled

Example:

n1000v(config-port-prof)# state enabled

n1000v(config-port-prof)#

Enables the port profile.

The configuration for this port profile is applied to the assigned ports, and the port group is created in the VMware vSwitch on the vCenter Server.

Step 11 

show port-profile name name

Example:

n1000v(config-port-prof)# show port-profile name multipath-profile

n1000v(config-port-prof)#

(Optional) Displays the current configuration for the port profile.

Step 12 

copy running-config startup-config

Example:

n1000v(config-port-prof)# copy running-config startup-config

(Optional) Saves the running configuration persistently through reboots and restarts by copying it to the startup configuration.

Additional References

For additional information related to implementing iSCSI Multipath, see the following sections:

Related Documents

Standards

Related Documents

Related Topic
Document Title

VMware SAN Configuration

VMware SAN Configuration Guide

Port Profile Configuration

Cisco Nexus 1000V Port Profile Configuration Guide, Release 4.0(4)SV1(2)

Interface Configuration

Cisco Nexus 1000V Interface Configuration Guide, Release 4.0(4)SV1(2)

Complete command syntax, command modes, command history, defaults, usage guidelines, and examples for all Cisco Nexus 1000V commands.

Cisco Nexus 1000V Command Reference, Release 4.0(4)SV1(2)


Standards

Standards
Title

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


Feature History for iSCSI Multipath

Table 13-2 lists the release history for the iSCSI Multipath feature.

Table 13-2 Feature History for iSCSI Multipath 

Feature Name
Releases
Feature Information

iSCSI Multipath

4.0(4)SV1(2)

Th iSCSI Multipath feature was added.


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