Asset ID:	1-71-1015442.1
Update Date:	2011-03-31
Keywords:

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Solution Type  Technical Instruction Sure

Solution  1015442.1 :   L700/180 - Explanation of Dynamic WWN Feature with Release of Library Code 3.04.03  


PreviouslyPublishedAs
223712

Applies to:

Sun StorageTek L1400 Tape Library
Sun StorageTek L180 Tape Library
Sun StorageTek L700 Tape Library
All Platforms
Checked for relevance on 31-Mar-2011.

Goal

Description
Explanation of Dynamic WWN Feature with Release of Library Code 3.04.03

Starting with 3.04.03 code, when enabling the dynamic World-Wide Name (dWWN) feature, be sure that all drive firmware is at the proper level to support dWWN.

Dynamic WWN feature ensures the customer that they will not have to reconfigure their host systems when a Fibre drive is replaced. To ensure this is the case, all Fibre drives in the library must support dWWN feature in order for the feature to be enabled.

Solution

Steps to Follow
The Dynamic WWN feature ensures the customer that they will not have to reconfigure their host systems when a fibre drive is replaced.
To ensure this is the case, all fibre drives in the library must support dWWN feature in order for the feature to be enabled. Starting with 3.04 code, when enabling the dynamic World-Wide Name (dWWN) feature, be sure that all drive firmware is at the proper level to support dWWN.

If a fiber drive has down-level firmware:
It will remain in the "configuring" state on the library operator panel and will be unavailable for customer use. This change was made so that customers who enable the dWWN feature can be assured that any fiber drive present in the library can be replaced without having to reconfigure their host system. It is inconsistent and undesirable to have some fiber drive replacements be transparent and other replacements require system re-configuration when dWWN is enabled.

Some implications of this change are:
Until T9x40 fiber drive firmware is available that supports the dWWN feature, the dWWN feature should not be enabled with 3.04 firmware when both T9x40 fiber drives and IBM LTO fiber drives are present. Once T9x40 supporting firmware is available, the T9x40 fiber drives can be up leveled and dWWN enabled.

An alternative for those who have a mixture of T9x40 and IBM LTO fiber drives is to remain at the 3.03 library firmware level until T9x40 supporting firmware is available. SCSI drives are unaffected by the dWWN feature. A library with a mixture of T9x40 SCSI drives and fiber drives which support dWWN can have dWWN enabled. In a library with only IBM LTO Gen1 fiber drives installed, all IBM LTO Gen1 drives must be at 27Q1 firmware level in order to enable the dWWN feature. Any IBM Gen1 drive that is not at 27Q1 or later firmware level would remain in the in "configuring state" at Library operator panel and would not be available for customer use.
Process to use Dynamic Worldwide Name Feature: Background:
To correct re-configuration problems within a customer's Fibre Channel network, 3.02 firmware includes the dynamic Worldwide Name (dWWN) enhancement. Previously, Fibre Channel devices contained fixed Worldwide Names within the network. If a device (for example, a defective tape drive) required replacement, the new device was detected by the network as is unknown it and re-configuration of the network was required. When enabled, dWWN assigns names to library drive slots rather than devices. When a drive is replaced, the new drive receives the same name as the one replaced, there by eliminating the need for system re-configuration.

There are three Worldwide Names reserved for the library and each drive slot: Node, Port A, and Port B.

Note:
1. This feature requires corresponding drive code that supports the dynamic Worldwide Name feature as well.  Make sure the drive code is current.

2. If you are asked any yes or no questions you must type the whole word example: continue yes or no .... type yes if you only type y in will go through the steps but will not work at the end. 

Enabling dWWN:
The dWWN feature (default set to OFF) is enabled through the CLI interface and, once enabled, the library must be IPL'd.

CAUTION: System problems: Changing the dWWN feature must be coordinated with the system administrator. The feature is usually enabled at installation time. A record of the configuration should be kept; this is not only something that should always be done, but it absolutely essential with the dWWN feature to eliminate system issues in the case of an MPC/MPCL failure.

To enable dWWN:
1. Through the CLI interface, type in
a. wwn xxx:xxx:xxx:xxx (where < xxx:xxx:xxx:xxx >. equals the 12-digit serial number of the library located on the agency approval sticker of the library). Be sure that each 3-digit group is separated by a colon. and press enter.
b. Type in: wwn enable and press ENTER.
2. IPL the library The library and drives will now contain the pre-assigned dWWN values that will not change as drives are replaced. a. type in: wwn view and press enter. this will let you verify that the enable worked or not. Disabling dWWN:

CAUTION: System problems: Changing the state of the dWWN feature must be coordinated with the system administrator.

To disable the dWWN:
1. Through the CLI interface, type in: wwn disable and press ENTER.
2. IPL the library. All supported Fibre Channel drives will return to their native WWN, requiring re-configuration with the host.



L700, L180, IBM LTO, Fibre interface drives, Dynamic WorldWide Name, Dynamic WWN, 9840, HP LTO, WWN, Gen2, 9x40, 3.04.03, 9940, Seagate LTO, 9940B, 9840C, 9840A, 9840B, 9940A, dWWN, Enable, How to enable WWN on library, How to disable WWN on library, Disable, audited
Previously Published As STKKB10991

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