W Commands

The commands in this chapter apply to the Cisco MDS 9000 Family of multilayer directors and fabric switches. All commands are shown here in alphabetical order regardless of command mode. See “About the CLI Command Modes” section to determine the appropriate mode for each command.

write command-id

To configure a SCSI write command for a SAN tuner extension N port, use the write command-id command.

write command-id cmd-id target pwwn transfer-size bytes [ outstanding-ios value [ continuous | num-transactions number ]]

 
Syntax Description

cmd-id

Specifies the command identifier. The range is 0 to 2147483647.

target pwwn

Specifies the target port WWN. The format is hh : hh : hh : hh : hh : hh : hh : hh.

transfer-size bytes

Specifies the transfer size in multiples of 512 bytes. The range is 512 to 8388608.

outstanding-ios value

(Optional) Specifies the number of outstanding I/Os. The range is 1 to 1024.

continuous

(Optional) Specifies that the command is performed continuously.

num-transactions number

(Optional) Specifies a number of transactions. The range is 1 to 2147483647.

 
Defaults

The default for outstanding I/Os is 1.

 
Command Modes

SAN extension N port configuration submode.

 
Command History

Release
Modification

2.0(x)

This command was introduced.

 
Usage Guidelines

To stop a SCSI write command in progress, use the stop command.

Examples

The following example configures a continuous SCSI write command:

switch# san-ext-tuner
switch(san-ext)# nWWN 10:00:00:00:00:00:00:00
switch(san-ext)# nport pwwn 12:00:00:00:00:00:00:56 vsan 13 interface gigabitethernet 1/2
switch(san-ext-nport)# write command-id 100 target 22:22:22:22:22:22:22:22 transfer-size 512000 outstanding-ios 2 continuous
 

 
Related Commands

Command
Description

nport pwwn

Configures a SAN extension tuner N port.

san-ext-tuner

Enables the SAN extension tuner feature.

show san-ext-tuner

Displays SAN extension tuner information.

stop

Cancels a SCSI command in progress on a SAN extension tuner N port.

write-accelerator

To enable write acceleration and tape acceleration for the FCIP interface, use the write-accelerator command in configuration mode. To disable this feature or revert to the default values, use the no form of the command.

write-accelerator [ tape-accelerator [ flow-control-butter-size bytes ]]

no write-accelerator [ tape-accelerator [ flow-control-butter-size ]]

 
Syntax Description

tape-accelerator

(Optional) Enables tape acceleration.

flow-control-butter-size bytes

(Optional) Specifies the flow control buffer size.

 
Defaults

Disabled.

The default flow control buffer size is 256 bytes.

 
Command Modes

Configuration mode.

 
Command History

Release
Modification

1.3(1)

This command was introduced.

2.0(x)

Added tape-accelerator and flow-control-butter-size options.

 
Usage Guidelines

The write acceleration feature is disabled by default and must be enabled on both sides of the FCIP link. If it is only enabled on one side of the FCIP tunnel, then the tunnel will not initialize.

In Cisco MDS SAN-OS Release 3.x, the write-accelerator command enables read acceleration if both ends of an FCIP tunnel are running SAN-OS Release 3.x.

If one end of an FCIP tunnel is running SAN-OS Release 3.x, and the other end is running SAN-OS Release 2.x, the write-accelerator command enables write acceleration only.

tip.gif

Tipblank.gif FCIP tape acceleration does not work if the FCIP port is part of a PortChannel or if there are multiple paths between the initiator and the target port. Such a configuration might cause SCSI discovery failure or broken write or read operations.

Examples

The following command enables write acceleration on the specified FCIP interface:

switch# config terminal
switch(config)# interface fcip 51
switch(config-if)# write-accelerator
 

The following command enables write acceleration and tape acceleration on the specified FCIP interface:

switch# config terminal
switch(config)# interface fcip 51
switch(config-if)# write-accelerator tape-accelerator
 

The following command disables tape acceleration on the specified FCIP interface:

switch# config terminal
switch(config)# interface fcip 51
switch(config-if)# no write-accelerator tape-acceleration
 

The following command disables both write acceleration and tape acceleration on the specified FCIP interface:

switch# config terminal
switch(config)# interface fcip 51
switch(config-if)# no write-accelerator
 

 
Related Commands

Command
Description

show interface fcip

Displays an interface configuration for a specified FCIP interface.

write erase

To clear a startup configuration, enter the write erase command from the EXEC mode prompt.

write erase [boot | debug]

 
Syntax Description

boot

(Optional) Destroys boot configuration.

debug

(Optional) Clears the existing debug configuration.

 
Defaults

None.

 
Command Modes

EXEC mode.

 
Command History

Release
Modification

1.0(2)

This command was introduced.

 
Usage Guidelines

Once this command is issued, the switch’s startup configuration reverts to factory defaults. The running configuration is not affected. The write erase command erases the entire startup configuration with the exception of any configuration that affects the loader functionality.

The write erase boot command only erases the configuration that affects the loader functionality. The loader functionality configuration includes the boot variables and the mgmt0 IP configuration information (IP address, netmask, and default gateway).

Examples

The following example clears the existing startup configuration completely:

switch# write erase
 

The following example clears the loader functionality configuration:

switch# write erase boot
This command will erase the boot variables and the ip configuration of interface mgmt 0

wwn oui

To add a new Cisco Organizationally Unique Identifier (OUI) to the OUI database, use the wwn oui command. To delete OUIs, use the no form of this command.

wwn oui id

no wwn oui { id | all }

 
Syntax Description

id

Specifies the OUI. The range is from 0x1 to 0xffffff.

all

Deletes all the user-defined OUIs.

 
Defaults

None

 
Command Modes

Global configuration (config)

 
Command History

Release
Modification

6.2(29)

This command was introduced.

 
Usage Guidelines

OUIs identify the manufacturer of SAN devices.

This command should be used when connecting another Cisco device to an MDS device when the MDS device does not recognize the other Cisco device as a Cisco device. The newly added device is usually not recognized when the NX-OS version on the MDS device is older than the other Cisco device. The other Cisco device can be another MDS device or it can be some other device such as a Cisco Nexus device.

Examples

The following example shows how to add an OUI to the OUI database:

switch# config terminal
switch(config)# wwn oui 0x1000
 

The following example shows how to delete an OUI from the OUI database:

switch# config terminal
switch(config)# no wwn oui 0x1000
 

 
Related Commands

Command
Description

show wwn oui

Displays all OUIs in the OUI database.

wwn secondary-mac

Allocates secondary MAC addresses.
 

wwn secondary-mac

To allocate secondary MAC addresses, use the wwn secondary-mac command.

www secondary-mac wwn-id range address-range

 
Syntax Description

wwn-id

The secondary MAC address with the format hh : hh : hh : hh : hh : hh.

range address-range

The range for the specified WWN. The only valid value is 64.

 
Command Modes

EXEC mode.

 
Command History

Release
Modification

1.0(2)

This command was introduced.

 
Usage Guidelines

This command cannot be undone.

Changes to the worldwide names are only performed as required. They should not be changed on a daily basis. These changes should be made by an administrator or individual who is completely familiar with switch operations.

Examples

The following example allocates a secondary range of MAC addresses:

switch(config)# wwnm secondary-mac 00:99:55:77:55:55 range 64
This command CANNOT be undone.
Please enter the BASE MAC ADDRESS again: 00:99:55:77:55:55
Please enter the mac address RANGE again: 64
From now on WWN allocation would be based on new MACs.
Are you sure? (yes/no) no
You entered: no. Secondary MAC NOT programmed

wwn vsan

To configure a WWN for a suspended VSAN that has interop mode 4 enabled, use the wwn vsan command in configuration mode. To discard the configuration, use the no form of the command.

wwn vsan vsan-id vsan-wwn wwn

no wwn vsan vsan-id vsan-wwn wwn

 
Syntax Description

vsan-id

Specifies the VSAN ID. The range is 1 to 4093.

vsan-wwn wwn

Specifies the WWN for the VSAN. The format is hh:hh:hh:hh:hh:hh:hh:hh.

 
Defaults

None.

 
Command Modes

Configuration submode.

 
Command History

Release
Modification

3.0(1)

This command was introduced.

 
Usage Guidelines

This command can succeed only if the following conditions are satisfied:

  • The VSAN must be suspended.
  • The VSAN must have interop mode 4 enabled before you can specify the switch WWN for it.
  • The switch WWN must be unique throughout the entire fabric.
  • The configured switch WWN must have McData OUI [08:00:88].

Examples

The following example shows how to assign a WWN to a VSAN.

switch# config t
switch(config)# wwn vsan 100 vsan-wwn 20:64:08:00:88:0d:5f:81
WWN can be configured for vsan in suspended state only
switch(config)# vsan database
switch(config-vsan-db)# vsan 100 suspend
switch(config-vsan-db)# exit
switch(config)# wwn vsan 100 vsan-wwn 20:64:08:00:88:0d:5f:81
switch(config)#

 
Related Commands

Command
Description

vsan database

Creates multiple fabrics sharing the same physical infrastructure, assigns ports to a VSAN, turns on or off interop mode, and load balances either per originator exchange or source-destination ID.