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FlexAttach Virtual pWWN

FlexAttach virtual pWWN feature facilitates server and configuration management. In a SAN environment, the server installation or replacement, requires interaction and coordination among the SAN and server administrators. For coordination, it is important that the SAN configuration does not change when a new server is installed, or when an existing server is replaced. FlexAttach virtual pWWN minimizes the interaction between the server administrator and the SAN administrator by abstracting the real pWWN using virtual pWWNs.

When FlexAttach virtual pWWN is enabled on an interface, a virtual pWWN is assigned to the server interface. The real pWWN is replaced by a virtual pWWN, which is used for a SAN configuration such as zoning.

Server administrators can benefit from FlexAttach in the following scenarios:

• Pre-configure—Pre-configure SAN for new servers that are not available physically yet. For example, they may be on order. FlexAttach can be enabled on the ports designated for the new servers and use the virtual WWNs assigned for configuring SAN. The new servers are then plugged into the fabric without any change needed in the SAN.
• Replacement to the same port—A failed server can be replaced onto the same port without changing the SAN. The new server gets a same pWWN as the failed server because the virtual pWWN is assigned to the port.
• Replacement to (spare)—A spare server, which is on the same NPV device or a different NPV device) can be brought online without changes to the SAN. This action is achieved by moving the virtual port WWN from the current server port to the spare port.
• Server Mobility—A server can be moved to another port on the same NPV device or another NPV device without changing the SAN. This is accomplished by moving the virtual pWWN to the new port. No change is needed if FlexAttach was configured using the physical port WWN of the server to the virtual port WWN mapping.

Difference Between San Device Virtualization and FlexAttach Port Virtualization

Table 59-1 describes the difference between SAN device virtualization (SDV) and FlexAttach port virtualization.

Table 59-1 Difference Between SDV and FlexAttach Virtualization

FlexAttach Virtual pWWN CFS Distribution

The FlexAttach virtual pWWN configuration is distributed for CFS through IPv4, and is enabled by default. The FlexAttach virtual pWWN distribution, by default, is on CFS region 201. The CFS region 201 links only to the NPV-enabled switches. Other CFS features such as syslog is on region 0. Region 0 will be linked through IPv4 for all NPV switches on the same physical fabric. If CFS has an option to link through IPv4 or ISL, then CFS will select the ISL path.

Note NPV switches do not have ISL (E or TE ports) and are linked through IPv4.

Security Settings for FlexAttach Virtual pWWN

Security settings for the FlexAttach virtual pWWN feature are done by port security at the NPV core. Node WWN of the end device is used to provide physical security.

For more details on enabling port security, refer to the Cisco MDS 9000 Family NX-OS Security Configuration Guide .

Automatically Assigning FlexAttach Virtual pWWN

Automatic assignment of virtual pWWN can be configured on an NPV switch globally, per VSAN, or per port. When assigned automatically, a virtual WWN is generated from the device local switch WWN.

Prerequisites

The port must be in a shut state when the virtual pWWN is enabled.

To assign a virtual pWWN automatically, perform this task:

To enable virtual pWWN automatically for all the interfaces, follow these steps:

Step 1 From the Device Manger menu bar, select FC > FlexAttach .

You see the FlexAttach window.

Step 2 Check the VirtualWwnAuto check box to enable automatic generation of virtual WWNs on all the fabric port interfaces.

Troubleshooting Tips

• When the interface-list value is not included in the command, virtual pWWN is assigned globally.
• All the interfaces mentioned in the interface-list value must be in a shut state.

Launching FlexAttach in DCNM-SAN

To launch FlexAttach in DCNM-SAN, follow these steps:

Step 1 In the Logical Domains pane, select a switch.

Step 2 In the Physical Attributes pane, expand Switches > FC Services > N_Port Virtualizer (NPV) > Flex Attach .

The FlexAttach configuration pane appears to the right.

Manually Assigning FlexAttach Virtual pWWN

You can manually assign a WWN to the interface, without generating it through the switch. Several checks are done by the NPV core to ensure the uniqueness of virtual pWWNs in the switch. When duplicate virtual pWWNs are configured, the subsequent logins are rejected by the NPV core switch.

Prerequisites

• Some ports may be in automode, some in manual mode, and the virtual pWWNs need not be assigned.
• The port must be in a shut state when a virtual pWWN is assigned.

Restrictions

• The interface mentioned in the interface value must be in a shut state.

To assign virtual pWWN manually, perform this task:

To enable virtual pWWN on each interface manually, follow these steps:

Step 1 In the Physical Attributes pane, expand Switches > FC Services > N_Port Virtualizer (NPV) > Flex Attach .

The FlexAttach configuration pane appears to the right.

Step 2 Click the Virtual pWWNs tab.

The Virtual pWWN tab view displays a list of the interfaces.

Step 3 Check the Auto check box to automatically generate the virtual pWWN value for the selected interface.

The virtual port WWN value for the selected interface in DCNM-SAN is automatically generated.

Mapping pWWN to Virtual pWWN

You can configure virtual pWWNs through real pWWNs. This process is required for NPIV hosts containing multiple pWWNs, of which only FLOGI is mapped to the virtual pWWN. Subsequent FDSIDs will have different mappings.

Several checks are done by the NPV core to ensure the uniqueness of virtual pWWNs in the switch across the NPV switches. When duplicate virtual pWWNs are configured, the subsequent logins are rejected by the NPV core switch.

Prerequisites

• The interface must be in a shut state and the specified virtual pWWN should not be logged in.

Restrictions

• The specified virtual pWWN and the real pWWN must not be logged in.

To map pWWN to virtual pWWN, perform this task:

To map pWWN to virtual pWWN, follow these steps:

Step 1 In the Physical Attributes pane, expand Switches > FC Services > N_Port Virtualizer (NPV) > Flex Attach .

Step 2 In the FlexAttach window, click the Physical to Virtual pWWNs tab.

You see the Physical to Virtual pWWNs tab view.

The LastChange field displays the time when the virtual pWWN was changed.

Using the Server Admin FlexAttach Wizards

As in DCNM for SAN Release 4.1(1) and later, the Server Admin perspective view of the DCNM-SAN GUI provides the following FlexAttach wizards, which the DCNM-SAN users with server-admin role can use to configure FlexAttach:

• Pre-Configuring FlexAttach for a New Server
• Moving a Server to Another Port or Switch
• Replacing a Server with Another Server

To access the FlexAttach wizards, follow these steps:

Step 1 Log in to DCNM-SAN with a username and password that has the server-admin role assigned.

Step 2 Discover and open the fabric on which you want to configure FlexAttach.

Step 3 In the DCNM-SAN window displayed, select Tools > NPV to display the list of NPV wizards that includes the Flex Attach options like Flex Attach Pre-Configure Server , Flex Attach Move Server , and Flex Attach Replace Server .

Pre-Configuring FlexAttach for a New Server

Using the Pre-configure Server wizard, you can configure FlexAttach for servers that are not physically available currently. FlexAttach can be enabled on the ports designated for the new servers and can use the virtual WWNs assigned for configuring SAN. When the new servers are available, the servers can then be plugged into the fabric without any change needed in the SAN.

The Pre-Configure Server wizard can be used to accomplish the following tasks:

• Pre-Configuring FlexAttach for All the Ports
• Pre-Configuring FlexAttach for Each Port Individually

Pre-Configuring FlexAttach for All the Ports

Using the Pre-Configure Server Basic configuration wizard, you can set the following port configurations for all the ports in one or more switches in common:

• Enable or disable FlexAttach Auto on all ports.
• Set the default VSAN ID for all the ports.
• Set the interface status for all the ports.

To pre-configure a common setting for all the ports in one or more switches, follow these steps:

Step 1 In the DCNM-SAN window, select Tools > NPV > Flex Attach Pre-configure Server .

The Pre-Configure Wizard is displayed.

Step 2 In the Pre-Configure Server window, click the Basic radio button to configure a common setting to all the ports on one or more switches. Click Next .

The Basic Configuration window is displayed.

Step 3 In the Basic Configuration window, check the check box to select one or more switches from the list of NPV switches in the fabric.

Step 4 Check the Enable FlexAttach Auto on every port check box to enable FlexAttach on all the ports of all the selected switches.

Step 5 (Optional) From the VSAN ID drop-down list, select a VSAN ID to assign the selected VSAN ID to all the ports.

Note Only the set of VSANs to which all the selected switches belong are listed. If no VSAN ID is selected, then the existing VSAN configuration is retained.

Step 6 Click the Up or Down radio button to assign the selected interface status.

Note The status of only the F ports in the selected switches will be brought to up or down state.

Step 7 Click Finish to pre-configure the selected settings to all the ports on all the selected switches.

The Configuration window is displayed with the finished applying the new configuration message.

Pre-Configuring FlexAttach for Each Port Individually

Using the Pre-Configure Server Advanced configuration wizard, you can set the following port configurations for each port in one or more switches individually:

• Enable FlexAttach Auto on all ports.
• Enable FlexAttach Auto or Manual on individual ports.
• Set the virtual pWWN for ports where FlexAttach is enabled Manually.
• Set pWWN to vPWWN mapping.
• Set the default VSAN ID for each port.
• Set the Interface status for each port.

To pre-configure FlexAttach on each port individually, follow these steps:

Step 1 In the DCNM-SAN window, select Tools > NPV > Flex Attach Pre-configure Server .

The Pre-Configure Server window is displayed.

Step 2 In the Pre-Configure Server window, click the Advanced radio button to configure FlexAttach on each port individually. Click Next .

The Pre-Configure Server Advanced configuration window is displayed.

Note From the Interface tab, you can select a switch from the list of switches displayed in the left pane and click Disable FlexAttach to change the switches to manual configuration. Select Undo Changes to return to the previous configuration.

Step 3 In the Interface tab, and select a switch from the list of switches displayed in the left pane.

The switch configuration details are displayed in the right pane with tabs and columns.

Step 4 Configure the following settings, for each interface:

• In the Status Admin column corresponding to the interface, double-click and then select up or down from the drop-down list.
• In the VSAN column corresponding to the interface, double-click and then select the VSAN ID from the drop-down list of existing VSAN IDs.
• In the Auto column corresponding to the interface, double-click and then select Auto to automatically enable FlexAttach or select Manual to manually enable FlexAttach later.
• In the Interface vPWWN cell, enter the vPWWN if Manual was selected in the Auto FlexAttach configuration cell.

Note You can click Set All Auto to change all the interfaces with manual FlexAttach configuration to Auto on the selected switch. However, if a valid virtual PWWN value is already configured, then changing it to Auto does not change the configuration. Before you change from Manual to Auto, update the Interface vPWWN column with the 00:00:00:00:00:00:00:00 value.

Step 5 Repeat Step 3 through Step 4 for each switch.

Step 6 Click the pWWN to vPWWN tab to configure pWWN to virtual PWWN mapping.

The Advanced Configuration window is displayed.

Step 7 From the Select a switch drop-down list, select the switch to display the existing pWWN to Virtual PWWN mapping table for the CFS region to which the switch belongs, and then follow these steps to add virtual pWWN to virtual pWWN automap entries:

a. Click Add Row to display the pWWN to vPWWN dialog box.

b. Enter the pWWN and the corresponding Virtual pWWN.

c. Click Create to add the mapping list.

Note To delete an existing mapping, select the row, and then click Delete Row. Only one pWWN to vPWWN table can be updated at a time. To update the table for each CFS region, perform
Step 6 though Step 8 for a switch from each CFS region.

Step 8 Click Finish to complete the configurations for each port.

Moving a Server to Another Port or Switch

Using the Move Server wizard, you can move a server to another port on the same NPV device or another NPV device without changing the SAN. This is accomplished by moving the virtual pWWN to the new port. No change is needed if FlexAttach was configured using the physical port WWN of the server to the virtual port WWN mapping.

To move a server to a different port in the same switch, or in a different switch, follow these steps:

Step 1 In the DCNM-SAN window, select Tools > NPV > FlexAttach Move Server .

The Move Server wizard is displayed.

Step 2 In the Move Server to.. window, click the Another Port on the Same Switch radio button or click the Another Port on a Different Switch radio button.

Step 3 Click Next .

The Choose Old Port window is displayed.

Step 4 From the Select a switch drop-down list, select a switch.

The switch ports are listed. To support moving a server from a failed port that is in down state, the ports in down state are also listed.

Step 5 From the list of interfaces, select the port from which you want to move the server from.

Step 6 Click Next .

The Choose New Port window is displayed.

Step 7 From the Select a switch drop-down list box, select a switch.

Note If the Another Port on the Same Switch radio button was chosen, then the Select a switch drop-down list is disabled.

Step 8 From the list of interfaces, select the port to which you want to move the server to.

Step 9 Click Next .

The Server WWN window is displayed.

In the Server WWN window, if the FlexAttach global mapping table is empty, the wizard automatically prefills the drop-down table with the interface virtual PWWN of the source port, and the virtual PWWN field is not editable.

If the FlexAttach global mapping table is not empty, the VPWWN field is blank and editable. From the drop-down list that displays all existing entries from the global mapping table, select the VPWWN entry or type the required entry.

Step 10 Click Finish .

Replacing a Server with Another Server

You can use the Replace Server wizard to accomplish the following tasks:

• Replace a failed server with a new server onto the same port without changing the SAN. The new server gets the same virtual pWWN as the failed server because the virtual pWWN is assigned to the port.
• Replace a server with a spare server on the same NPV device or a different NPV device, which can be brought online without changes to the SAN. This is achieved by moving the virtual port WWN from the current server port to the spare port.

Replacing a Server on the Same Port

To replace a failed server with a new server on the same port, follow these steps:

Step 1 In the DCNM-SAN window, select Tools > NPV > FlexAttach Replace Server .

The Replace Failed Server window is displayed.

Step 2 In the Replace Server Wizard, click the On Same Port radio button.

Step 3 Click Next .

The Choose Failed Port window is displayed.

Step 4 In the Choose Failed Port selection window, from the Select a switch drop-down list, select the switch.

Step 5 From the list of interfaces displayed, select the port on which the server needs to be replaced.

Step 6 Click Next .

The Server WWN window is displayed.

Step 7 In the Server WWN window, enter the existing FlexAttach server virtual port WWN that needs to be replaced, and the new server physical port WWN.

Step 8 Click Finish to complete the FlexAttach configuration for the new server.

Replacing the Server to a Different Port on the Same Switch

To replace a server with a spare server on a different port in the same switch, follow these steps:

Step 1 In the DCNM-SAN window, select Tools > NPV > FlexAttach Replace Server .

The Replace Failed Server wizard is displayed.

Step 2 In the Replace Failed Server wizard, click the With Spare Server on Same NPV Switch radio button.

Step 3 Click Next .

The Choose Failed Port window is displayed.

Step 4 In the Choose Failed Port selection window, from the Select a Switch drop-down list, select the switch.

Step 5 From the list of interfaces displayed, select the port from which the server needs to be detached.

Step 6 Click Next .

The Choose New Port window is displayed.

Step 7 In the Choose New Port selection window, select the port on which the spare server is connected.

Step 8 Click Next .

The Server WWN window is displayed.

In the Server WWN window, if the FlexAttach global mapping table is empty, the wizard automatically prefills the drop-down table with the interface virtual vPWWN of the source port to be replaced, and the vPWWN field is not editable. In this case, the Allow wizard to change from “pWWN to vPWWN” mapping to “interface to vPWWN” mapping is treated as true.

If the FlexAttach global mapping table is not empty, the vPWWN field is blank and editable. From the drop-down list that displays all existing entries from the global mapping table, select the vPWWN entry or type the required entry, and the new server physical port WWN.

Check the Allow wizard to change from “pWWN to vPWWN” mapping to “interface to vPWWN” mapping check box to remove the pWWN to vPWWN entry from the CFS Region mapping table, and configure the mapping only at the interface.

Step 9 Click Finish to complete the FlexAttach configuration for the spare server.

Replacing with a Server on a Different Switch

To replace a server with a spare server on a different switch, follow these steps:

Step 1 In the DCNM-SAN window, select Tools > NPV > FlexAttach Replace Server .

The Replace Server wizard is displayed.

Step 2 In the Replace Server wizard, click the With Spare Server on a Different NPV switch radio button.

Step 3 Click Next .

The Failed Server Port window is displayed.

Step 4 In the Failed Server Port selection window, from the Select a Switch drop-down list, select the switch.

Step 5 From the list of interfaces displayed, select the port from which the server needs to be detached.

Step 6 Click Next .

The New Port window is displayed.

Step 7 In the New Port selection window, select the switch and the port on which the spare server is connected.

Step 8 Click Next .

The Server WWN window is displayed.

In the Server WWN window, if the FlexAttach global mapping table is empty, the wizard automatically prefills the table with the interface virtual vPWWN of the source port to be replaced, and the vPWWN field is not editable. In this case, the Allow wizard to change from “pWWN to vPWWN” mapping to “interface to vPWWN” mapping is treated as true.

If the FlexAttach global mapping table is not empty, the vPWWN field is blank and editable. From the drop-down list box which displays all existing entries from the global mapping table, select the vPWWN entry or type the required entry, and the new server physical port WWN.

Check the Allow wizard to change from “pWWN to vPWWN” mapping to “interface to vPWWN” mapping check box to remove the pWWN to vPWWN entry from the CFS Region mapping table, and configure the mapping only at the interface.

Step 9 Click Finish to complete the FlexAttach configuration for the spare server.

Verifying the End Device

To verify that the end device is logged with the correct virtual WWNs, use the show fcns database command on the NPV core. (See Example 59-2.)

Example 59-2 Verifying the End Device

Total number of entries = 4