Network StorEdge Engineering are constantly updating and reviewing
the most appropriate ways to configure Sun StorEdge devices to achieve
the maximum reliability and stabilty of the StorEdge product set.

These changes are usually detailed in the User and Install documentation,
and as such it is strongly recommended that engineers installing ANY Sun 
equipment periodically review the documentation provided to ensure that 
latest practices and installation guidelines are being adhered to.

One of these changes is to the A5X00 array and host, hub slot cabling sequence.

The current engineering guidelines as detailed in the Network Array
Configuration Guide 805-0264-XX (-14 at the date of writing this INFODOC) 
supplied with every A5X00 Array details the following as the new recommended 
guideline for A5x00 arrays and host slot placement in hubs.


 Hub Slot    0       1       2       3       4      5        6
   	  ---------------------------------------------------------
 	  |  4th  |  3rd  |  2nd  |  1st  | 1st   | 2nd  | UNUSED |
  	  | ARRAY | ARRAY | ARRAY | ARRAY | HOST  | HOST |	  |	
  	  ---------------------------------------------------------

Please Note: There should be NO gaps eg: with only 1 host and 1 array 
connected hub slot position 4 would have the host connection and slot 
position 3 the A5X00 array. It also not recommended to leave GBIC's 
inserted in hubs with no active device connected.

Engineering tests have shown that this latest hub configuration gives
improved FC-AL signal quality and a more reliable FC-AL signal retransmission.

Those customer sites that have hubs configured in the original method 
(as detailed in pre -14 versions of the 805-0264-XX Network Array
Configuration Guide) should at a convenient time update their configuration 
to the latest guidelines to ensure that the marginal problems that have been 
observed under some operating conditions are prevented. 

Those sites that are seeing marginal A5X00 related errors may benefit
from updating their hub configurations to these latest guidelines. 

This does not preclude the use of good diagnosis techniques to find the true 
cause of a reported A5X00 FC-AL problem. As is normal after any FC-AL
component change or reconfiguration STORtools mpat_lbf tests should be 
run as a minimum test to confirm correct FC-AL loop operability.