Table Of Contents

Configuring SANTap

About SANTap

Configuring SANTap

Enabling SANTap

Configuring DVTs

Displaying SANTap Information

Removing Appliance-Generated Entities

Removing AVTs and AVT LUNs

Removing SANTap Sessions

Removing Initiator-Target-LUNs

Default Settings

Enabling SANTap on SSM

Configuring SANTap

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The Storage Services Module (SSM) supports SANTap in Cisco MDS SAN-OS Release 2.0(2b) and later.

This chapter includes the following sections:

•About SANTap

•Configuring SANTap

•Displaying SANTap Information

•Removing Appliance-Generated Entities

•Default Settings

•SANTap support on Cisco MDS 9000 Family 18/4-Port Multiservice Module (MSM-18/4)C, page 50-9

About SANTap

The SANTap feature allows third-party data storage applications, such as long distance replication and continuous backup, to be integrated into the SAN. The protocol-based interface that is offered by SANTap allows easy and rapid integration of the data storage service application because it delivers a loose connection between the application and an SSM, which reduces the effort needed to integrate applications with the core services being offered by the SSM. See Figure 50-1.

Figure 50-1 Integrating Third-Party Storage Applications in a SAN

SANTap has a control path and a data path. The control path handles requests that create and manipulate replication sessions sent by an appliance. The control path is implemented using an SCSI-based protocol. An appliance sends requests to a Control Virtual Target (CVT), which the SANTap process creates and monitors. Responses are sent to the control LUN on the appliance. SANTap also allows LUN mapping to Appliance Virtual Targets (AVTs). You can have a maximum of 512 target LUNs.

SANTap does not require reconfiguration of either the host or target when introducing SANTap-based applications. Also, neither the host initiator nor the target is required to be directly connected to an SSM. This is accomplished by assigning Cisco-specific WWNs to the virtual initiators (VIs) and Data Virtual Targets (DVTs). A host initiator or a target can be connected directly to an SSM. However, you must partition the SAN using VSANs.

You must configure the host initiator and the DVT in one VSAN and configure the VI and the target in another VSAN. See Figure 50-2.

Figure 50-2 SANTap Proxy Mode-2 Example

You can use SANTap to remove your appliance-based storage applications from the primary data path in SAN. Removing these applications from the primary data path prevents them from compromising the security, availability, and performance of the SAN. SANTap copies the data at line speed and makes it available to other storage applications; these storage applications are prevented from affecting the SAN while maintaining the integrity of the data that storage applications need.

Dynamic LUN is a feature introduced in the Cisco SAN OS release 3.2(1). When one or more LUNs are removed or added on the backend target during the periodic scan, SANTap automatically uninstalls the deleted DVT LUNs and installs any additional LUNs. Uninstallation of the deleted DVT LUNs is done even if the total number of LUNs remains the same.

In previous releases, when the set of LUNs changed on the target, the original LUN list was displayed on the DVT. The new and changed LUNs were not reflected on the DVT. However, if the total number of LUNs increases, then the additional LUNs are installed and displayed on the host.

Before Cisco SAN OS release 3.2(1), a user had the following options for displaying the LUN list on DVT:

•Shut the host interface- Purge the DVT LUNs for the IT pair using CLI. All the LUNs for the existing IT pair was removed, and the correct set of LUNs is recreated when the host logs in.

•Reload the SSM.

64-Bit LUN Support- In Cisco SAN OS release 3.2(1) or later releases, SANTap supports 64-bit LUNs on the target.

The following CLI commands are used to obtain the mapping between the host-side LUN and the target-side LUN:

Switch# show santap module <num> dvtlun
Switch# show santap module <num> dvtlun brief

Module# show santap vttbl dvt <dvt_wwn> host <host_wwn>

Configuring SANTap

This section includes the following topics:

•Enabling SANTap

•Configuring DVTs

Enabling SANTap

SANTap can be enabled on an entire SSM or it can be enabled on a group of four ports on an SSM. Enabling SANTap on interfaces has the following restrictions:

•The fewest number of interfaces that you can enable is four. You can specify ports 1 through 4 but not ports 1 through 2.

•The first interface in the group must be 1, 5, 9, 13, 17, 21, 25, or 29. You can specify ports 5 through 8 but not ports 7 through 10.

•The groups of four interfaces do not need to be consecutive. You can specify ports 1 through 8 and ports 17 through 20.

To enable the SANTap feature, follow these steps:

	Command	Purpose
Step 1	switch# config t switch(config)#	Enters configuration mode.
Step 2	switch(config)# ssm enable feature santap module 4	Enables the SANTap application on the entire SSM in slot 4.
	switch(config)# no ssm enable feature santap module 4	Disables the SANTap application on the entire SSM in slot 4.
Step 3	switch(config)# ssm enable feature santap interface fc 4/1 - 4	Enables the SANTap application on ports 1 through 4 on the SSM. Note Interfaces must be specified in multiples of four beginning at ports 1, 5, 9, 13, 17, 21, 25, and 29.
	switch(config)# no ssm enable feature santap interface fc 4/1 - 4	Disables the SANTap application on ports 1 through 4 on the SSM in slot 4.
Step 4	switch(config)# santap module 4 appl-vsan 10	Creates SANTap CVTs on the SSM in slot 4 and on VSAN 10.
	switch(config)# no santap module 4 appl-vsan 10	Deletes CVT.

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Note You cannot simultaneously configure the intelligent services SANTap on a single SSM.

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Configuring DVTs

To configure a DVT, follow these steps:

	Command	Purpose
Step 1	switch# config t switch(config)#	Enters configuration mode.
Step 2	switch(config)# santap module 2 dvt target-pwwn 50:06:0e:80:03:81:32:36 target-vsan 9 dvt-name MYDVT dvt-vsan 12	Configures the pWWN, target VSAN (which contains the target and VI), DVT name, and DVT VSAN (which contains the host and the CVT).
	switch(config)# santap module 2 dvt target-pwwn 50:06:0e:80:03:81:32:36 target-vsan 9 dvt-name MYDVT dvt-vsan 12 dvt-port 1	Configures the pWWN, target VSAN, DVT name, DVT VSAN, and DVT port. Note Santap has to be provisioned for the whole module 2. When using the interface command, it should be provisioned on interface fc1/1-4. If not, you will not be able to provide the dvt-port option. The DVT port maps to one of the ports on the SSM. You can assign a port for explicit load balancing or not assign a port, which allows the SSM to select the port and handle the load balancing (default).
	switch(config)# santap module 2 dvt target-pwwn 50:06:0e:80:03:81:32:36 target-vsan 9 dvt-name MYDVT dvt-vsan 12 lun-size-handling 1	Configures the pWWN, target VSAN, DVT name, DVT VSAN, and LUN size handling flag (enabled). Enabling the LUN size handling flag allows special LUN resize handling by the vendor. The default LUN size handling flag value is 1(enabled).
	switch(config)# santap module 2 dvt target-pwwn 50:06:0e:80:03:81:32:36 target-vsan 9 dvt-name MYDVT dvt-vsan 12 io-timeout 20	Configures the pWWN, target VSAN, DVT name, DVT VSAN, and IO timeout value in seconds. The IO timeout determines the interval after which to time out I/Os on the target side. The range is 10 to 200 seconds and the default value is 10 seconds.
	switch(config)# no santap module 2 dvt target-pwwn 50:06:0e:80:03:81:32:36	Removes the DVT configuration.

In Cisco SAN OS release 3.2(1) or later releases, SANTap supports 32 host initiators per DVT.

Displaying SANTap Information

Use the show santap module command to display information about SANTap (see Example 50-1 to Example 50-8).

Example 50-1 Displays SANTap CVT Information

switch# show santap module 2 cvt

CVT Information :

        cvt pwwn     = 23:4f:00:0d:ec:09:3c:02

        cvt nwwn     = 23:9d:00:0d:ec:09:3c:02

        cvt id       = 135895180

        cvt xmap_id  = 135895212

        cvt vsan     = 8

        cvt name     = 

Example 50-2 Displays SANTap DVT Information

switch# show santap module 2 dvt

DVT Information :

       dvt pwwn     = 50:06:0e:80:03:81:32:36

       dvt nwwn     = 50:06:0e:80:03:81:32:36

       dvt id       = 136773180

       dvt mode     = 3

       dvt vsan     = 12

       dvt if_index = 0x1080000

       dvt fp_port  = 1

       dvt name     = MYDVT

       dvt tgt-vsan = 9

       dvt io timeout            = 10 secs

       dvt lun size handling     = 0

       dvt app iofail behaviour  = 1

       dvt quiesce behavior      = 1

       dvt tgt iofail behavior   = 0

       dvt appio failover time   = 50 secs

       dvt inq data behavior     = 0

Example 50-3 Displays SANTap DVT LUN Information

switch# show santap module 2 dvtlun

 DVT LUN Information :

        dvt pwwn     = 22:00:00:20:37:88:20:ef

        dvt lun      = 0x0

        xmap id      = 8

        dvt id       = 3

        dvt mode     = 0

        dvt vsan     = 3

        tgt pwwn     = 22:00:00:20:37:88:20:ef

        tgt lun      = 0x0

        tgt vsan     = 1

Example 50-4 Displays SANTap Session Information

switch# show santap module 2 session

Session Information :

        session id   = 1

        host pwwn     = 21:00:00:e0:8b:12:8b:7a

        dvt pwwn     = 50:06:0e:80:03:81:32:36

        dvt lun      = 0x0

        tgt pwwn     = 50:06:0e:80:03:81:32:36

        tgt lun      = 0x0

        adt pwwn     = 33:33:33:33:33:33:33:00

        adt lun      = 0x0

        aci pwwn     = 22:22:22:22:22:22:22:22

        cvt pwwn     = 23:4f:00:0d:ec:09:3c:02

        num ranges   = 0

        session state = 5

        redirect mode = 0

        mrl requested 1

        MRL : vsan 8 RegionSize 4806720, DiskPWWN 0x234f000dec093c02, DiskLun 0x 1, 
startLBA 1

        pwl requested 1

        PWL : type 2, UpdatePol 2, RetirePolicy 4, pwl_start 1

        iol requested 0

Example 50-5 Displays SANTap AVT Information

switch# show santap module 2 avt

 AVT Information :

        avt pwwn     = 2a:4b:00:05:30:00:22:25

        avt nwwn     = 2a:60:00:05:30:00:22:25

        avt id       = 12

        avt vsan     = 4

        avt if_index = 0x1080000

        hi pwwn      = 21:00:00:e0:8b:07:61:aa

        tgt pwwn     = 22:00:00:20:37:88:20:ef

        tgt vsan     = 1

Example 50-6 Displays SANTap AVT LUN Information

switch# show santap module 2 avtlun

 AVT LUN Information :

        avt pwwn     = 2a:4b:00:05:30:00:22:25

        avt lun      = 0x0

        xmap id      = 16

        avt id       = 12

        tgt lun      = 0x0

Example 50-7 Displays SANTap Remote Virtual Terminal Information

switch# show santap module 2 rvt

 RVT Information :

        rvt pwwn     = 2a:61:00:05:30:00:22:25

        rvt nwwn     = 2a:62:00:05:30:00:22:25

        rvt id       = 17

        rvt vsan     = 4

        rvt if_index = 0x1080000

Example 50-8 Displays SANTap Remote Virtual Terminal LUN Information

switch# show santap module 2 rvtlun

 RVT LUN Information :

        rvt pwwn     = 2a:61:00:05:30:00:22:25

        rvt lun      = 0x0

        xmap id      = 22

        rvt id       = 17

        app pwwn     = 22:00:00:20:37:39:b1:00

        app lun      = 0x0

        app vsan     = 1

Removing Appliance-Generated Entities

An appliance might terminate its SANTap application without removing generated entities on the MDS switch. This section describes how to remove these entities using the CLI on the MDS switch.

This section includes the following topics:

•Removing AVTs and AVT LUNs

•Removing SANTap Sessions

•Removing Initiator-Target-LUNs

Removing AVTs and AVT LUNs

Occasionally the AVT and AVT LUN configuration remains after a SANTap application terminates. To remove AVTs and AVT LUNs, follow these steps:

	Command	Purpose
Step 1	switch# show santap module 2 avt	Displays the AVT pWWNs.
	switch# show santap module 2 avtlun	Displays the AVT pWWNs and LUNs
Step 2	switch# clear santap module 2 avt 2a:4b:00:05:30:00:22:25 lun 234456	Removes a LUN from the AVT.
	switch# clear santap module 2 avt 2a:4b:00:05:30:00:22:25	Removes the AVT. Note You can remove the AVT only after all the LUNs are removed.

Removing SANTap Sessions

Occasionally a SANTap session continues after a SANTap application terminates. To remove a SANTap session, follow these steps:

	Command	Purpose
Step 1	switch# show santap module 2 session	Displays SANTap session information on the SSM in slot 2.
Step 2	switch# clear santap module 2 session 1	Removes SANTap session 1 on the SSM in slot 2.

Removing Initiator-Target-LUNs

The initiator-target-LUN (ITL) triplet identifies a LUN loaded on a DVT. Occasionally the ITL configuration remains after a SANTap application terminates. To remove all LUNs for an ITL triplet, follow these steps:

	Command	Purpose
Step 1	switch# show santap module 2 dvtlun	Displays the target and host pWWNs for the ITLs on the SSM in slot 2.
Step 2	switch# clear santap module 2 itl target-pwwn 22:00:00:20:37:88:20:ef host-pwwn 22:00:00:20:37:88:20:ef	Removes an IT L on the SSM in slot 2.

Default Settings

Table 50-1 lists the default settings for SANTap parameters.

Table 50-1 Default SANTap Parameters 

Parameters	Default
SANTap feature	Disabled.
DVT IO timeout	10 seconds.
DVT LUN size handling flag	1 (enabled).

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Note LUN-size handling flag is enabled by default.

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Enabling SANTap on SSM

SANTap can be enabled on SSM.

The following command enables SANTap on SSM:

switch(config)#
switch# ssm enable feature santap module 1