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Conference ssag::ask_ssag

Title:Ask the Storage Architecture Group
Notice:Check out our web page at http://www-starch.shr.dec.com
Moderator:SSAG::TERZAN
Created:Wed Oct 15 1986
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:6756
Total number of notes:25276

6559.0. "SCSI problem in Alphaserver 4100" by TAINO::JFUSTE (JOSE FUSTE) Mon Apr 07 1997 14:06

    I wrote a note in the Alphaserver 4100 conference about a problem using
    the following personality module;
    			70-31490-01
    We don't know yet if the problem is the personality but I was following
    note number 93.21 in the Alphaserver 4100 conference and looks the
    same. The note I wrote is 525. If somebody can help me out my customer
    will be more than satisfy.
    
    Thanks,
    	Jose
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6559.1Reference note.. I pointed Jose to ASK_SSAG. Can someone help him out?MAY30::CUMMINSTue Apr 08 1997 10:12105
      <<< MVBLAB::SYS$SYSDEVICE:[NOTES$LIBRARY]ALPHASERVER_4100.NOTE;1 >>>
                             -< AlphaServer 4100 >-
================================================================================
Note 93.21                        Field Blitzes                         21 of 45
LANDO::CUMMINS                                       98 lines   4-NOV-1996 08:47
       -< BA356 enclosures, RZ29B's, RZ28D's , DWZZB-VW's, and SWXA2-BA >-
--------------------------------------------------------------------------------
+---------------------------+TM
|   |   |   |   |   |   |   |
| d | i | g | i | t | a | l |      TIME   DEPENDENT   BLITZ
|   |   |   |   |   |   |   |      
+---------------------------+


   
      BLITZ TITLE: BA356 enclosures, RZ29B's, RZ28D's , DWZZB-VW's 
                   and SWXA2-BA (MVD) 
 
                                                DATE: November 1, 1996
      AUTHOR: Charles Schnare                   TD #: 
      DTN:237 3639         
      ENET:SUBSYS::SCHNARE  	   		CROSS REFERENCE #'s:
      DEPARTMENT: Adapters and Backplane        (PRISM/TIME/CLD#'s) 
                  Controllers Engineering
                                                
         					
                                                        
      INTENDED AUDIENCE: U.S/EUROPE/GIA		PRIORITY LEVEL: 1 
                         
                                                 (1=TIME CRITICAL,
                                                  2=NON-TIME CRITICAL)
      =====================================================================

Subject : BA356 enclosures, RZ29B's. RZ28D's , DWZZB-VW's and SWXA2-BA (MVD) 


PROBLEM OVERVIEW:
-----------------
  
  Storage  BA356  enclosures using a combination of AC power supplies, 
  DWZZBs, and RZ29Bs or RZ28Ds can exhibit SCSI command time-outs. The 
  result  of  these time-outs is interrupted I/O between the subsystem 
  and the host.
  
  
CONFIGURATIONS AFFECTED:
------------------------
  
  The specific configurations that could be affected are as follows;
     
  	1) BA356 enclosures, utilizing AC power supplies, and a 
           combination  of one (1) DWZZB-VWs and four (4) or more 
           RZ29Bs or RZ28Ds.
  
  	2) BA356 enclosures, utilizing AC power supplies, and a 
           combination  of two (2) DWZZB-VWs and three (3) or more 
           RZ29Bs or RZ28Ds.
  
  
TECHNICAL DETAIL:
-----------------
  
  In  the  above  mentioned  subsystem configuration,  the  cumulative
  voltage  drops  across  the  subsystems  power  distribution  system
  (which  includes the power supply, backplane, loads,  flex  circuit,
  and DWZZB-VW itself) can cause the low voltage sensor  on the DWZZB-
  VW  to trigger. This will cause the SCSI bus to go into a bus   free
  state  on  the target side, resulting in SCSI bus command time-outs.
  The  nature of the problem is such that some of these configurations
  will in fact operate error free.
  

  AFFECTED SERIAL NUMBER RANGE: N/A; Rev A02 DWZZB-VW units.
                                     Rev A02 SWXA2-BA (MVD)
  
Short Term Work Arounds:
------------------------
  
  Corrective  action is only required IF you have a storage  subsystem
  matching  the above configurations AND it is exhibiting  the  system
  symptoms described above. There are two proposed work arounds.
  
        1. Add a Second Power Supply. We have found that in most cases
           adding a second power supply will correct the problem.
  
        2. Depopulate  the BA356 enclosures to one (1)  DWZZB-VW  and
           four  (4)  RZ29Bs or RZ28Ds or depopulate BA356 enclosures  
           with two (2) DWZZB-VW's and three (3) RZ29Bs or RZ28Ds.
  
  
Long Term Solution:
-------------------
  
  Corrective  action is only required IF you have a storage  subsystem
  matching  the  above  configurations AND its exhibiting  the  system
  symptoms described  above. There is one long term solution.
  
       1. Replace the Rev A02 DWZZB-VW units with, Rev B01 DWZZB-VW.
  
NOTE: This  ECO work  has  just started in manufacturing. It  will  be 
      some  number  of weeks before ECO'd units will be  available  at
      your  local  field  service  stockrooms.  Short  term  solutions
      listed   above   will  correct  the  problem  until   there   is
      availability in the field service stockrooms.
  
6559.2More on this topic..MAY30::CUMMINSTue Apr 08 1997 10:1225
      <<< MVBLAB::SYS$SYSDEVICE:[NOTES$LIBRARY]ALPHASERVER_4100.NOTE;1 >>>
                             -< AlphaServer 4100 >-
================================================================================
Note 525.15                  SCSI bus going offline                     15 of 15
TAINO::JFUSTE "JOSE FUSTE"                           18 lines   7-APR-1997 14:51
                         -< DWZZB-VW and 70-31490-01 >-
--------------------------------------------------------------------------------
    Bill,
    	Note 93.21 reffered to the DWZZB-VW. What the customer has is the
    following part number:
    			70-31490-01 rev.a03
    
    I tried to order via logistics revision B01 for this type of
    personality and they told us that the latest revision is A04. Following
    note 93.21 both are totally different. It take a long time for
    logistics to find out that this is the latest revision for this module.
    The customer has revision A03. They still getting errors from the same
    SCSi bus (C). Is revision A04 for this module do the same as revision
    B01 in the DWZZB-VW?
    
    Please let me know what to try next.
    
    Thanks,
    	Jose
    	
6559.3HOUNDD::BASSETTBillTue Apr 08 1997 14:306
    7031490-01 rev A04 varies from the A03 rev in how the personality card
    is assembled.  It addressed a concern we had with the alignment of the 
    68pos connectors to the sheet metal.  The change is totally unrelated to 
    the DWZZB power issue.  
    
    				Bill