Last Revised
AST RESEARCH, INC.        TECHNICAL BULLETIN # 1728          06/10/97 
 
 
 
TITLE:  Seagate SCSI Hard Drive Differences
 
 
ISSUE 
 
   The Seagate two and four GB hard drives, part numbers ST32430N 
   and ST15230N, originally used in the Manhattan P and V series 
   servers, are no longer available. These drives have been replaced 
   by the Seagate ST32171N and ST34371N drives which are narrow 
   Ultra SCSI drives.
   
   Although the newer Ultra SCSI drives have been tested and are 
   compatible as a direct replacement (for factory-qualified AST 
   configurations), there are minor jumper differences between the 
   new Barracuda drives and the older Hawk drives. Those who are 
   familiar with the older drives should take extra care when 
   setting the jumpers on these new drives. 
   
   Pay particular attention to the "Parity" jumper.  On the 
   previously qualified drives, this was a "Parity Enable" jumper. 
   On the new drives, the corresponding jumper is "Parity Disable", 
   and therefore should not be installed.
   
   The other major difference is the attachment of the SCSI ID 
   cable. This cable attaches from the tray edge card to the front 
   header connector on the drive. The arrangement of the pins on the 
   Barracuda is opposite from that on the Hawk model.
   
   
                                         _____  SCSI ID jumpers
                                        /
   |                                   ^       | 
   |     Hawk (front)          ______ / \      |
   |__________________________|______|::::::___|
                                      421
   
   
                                            _____  SCSI ID jumpers
                                           /
   |                                      ^    | 
   |     Barracuda (front)     ______    / \   |
   |__________________________|______|::::::___|
                                         421
   
   This issue affects all Manhattan P and V series servers.    

 
BACKGROUND 
 
   N/A    

 
ACTION 
 
   N/A    

 
NOTES 
 
   Although the narrow Ultra SCSI drives can be considered a direct 
   replacement into a RAID built from standard drives, the reverse 
   is not true.    

 
TAN TPR 17530JB 
 
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