RS6000/J30 HOT SWAPPABLE DISK

ITEM: RTA000054896



QUESTION:                                                                       
Regarding the RS6000/J30 Hot Swappable Disk:                                    
                                                                                
1. Are they dependent on the operating system? Why are they only                
available on the J30?                                                           
                                                                                
2. Where can I find specifications on these disks? Announcement Letter?         
Sales Manual?                                                                   
                                                                                
Thanks in advance for your assistance.                                          
                                                                                
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A:    Question 1:                                                               
                                                                                
   If your first question is concerning why the hot-pluggable disk is          
   not available on the G30 and R30 SMP machines, then I can not provide        
   you a definite reason.  This may be due to a marketing decision or           
   due to an engineering design decision.                                       
                                                                                
   Question 2:                                                                  
                                                                                
   Specifications on the 1.1GB SCSI-2 F/W disk and the 2.2GB SCSI-2 F/W         
   disk can be found in the Systems Overview and Planning on page 1-96          
   (GC23-2406-05).  Some of the basic statistics for the disk drives are        
   copied below from the Salesmanual:                                           
                                                                                
                          Average                           Media               
              Formatted   Seek      Average    Rotational   Transfer            
  Models      Capacity    Time      Latency    Speed        Rate                
  ------      ---------   ------    -------    ---------    --------           
   112          1.1 GB     7.2ms     4.17ms     7200 RPM    20 MB/sec           
   317          2.2 GB     7.8ms     4.17ms     7200 RPM    20 MB/sec           
                                                                                
   If you or your customer have a definite need for hot-pluggable disks         
   on other SMP machines, please submit an RPQ (Request for Price               
   Quotation) or REQUEST to Development.  This would allow Development          
   a chance to comment feasibility of the future support of this                
   product and alert IBM to the need for such an offering.                      
                                                                                
   Thank you.                                                                   
                                                                                
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QUESTION:                                                                       
Thank you for your response.  Could you please check to see why the             
Hot Swappable is available on the J30 only, engineering or marketing?          
And why, if it is an engineering reason?Is the Hot Swappable Operating          
System dependent or is there another technical reason it only runs on           
the J30?                                                                        
                                                                                
Also, is the Systems Overview & Planning Guide the only source for              
information on the hot swappable disk technology.  I could not find             
very much info there.  What about announcement letter's or salesman?            
                                                                                
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A:                                                                              
   Based on pre-release notes that I have studied, the decision to have         
   hot-pluggable disks in the initial design of the mid-range J30 SMPs          
   appears to have been a marketing decision.  There are no specific            
   limitations that we at ASKQ know of related to the development and           
   design of the G30 and R30 that would prevent one from installing            
   hot-swappable disks.  The hot pluggable bays require additional              
   mounting hardware to allow SE devices to connect to the DE adapter           
   bus and to allow the drives to be easily removed.                            
                                                                                
   We can only speculate further.                                               
                                                                                
   Information about the disk drives:                                           
   This information is available in the 194-324 IBM RISC SYSTEM/6000            
   STORAGE I/O announcement letter dated 10-4-94:                               
                                                                                
       The new 1.1GB, 2.2GB, and 4.5GB SCSI-2 Fast/Wide Disk Drives,            
   and the 1.1GB and 2.2GB Disk Drives, are high-performance 3.5-inch           
   form-factor disk drives that attach via an ANSI-SCSI-2 interface.            
   These compact drives provide additional price performance and growth         
   options for the RISC System/6000 family of systems.                         
   o   Form Factor:  3.5-inch                                                   
   o   Cable included:  No                                                      
   o   External Interface:  SCSI (8-bit and 16-bit, single-ended models)        
   o   Attachment Industry Spec:  ANSI/SCSI-2                                   
   o   SCSI Bus Interface Speed:  10MB on 8-bit models, 20MB on 16-bit          
       models                                                                   
   o   Command Set:  SCSI-2                                                     
   o   Average Seek Time:  1.1GB = 7.2ms, 2.2GB = 7.8ms, 4.5GB = 8.3ms          
       (Average of four reads and one write)                                    
   o   Average Latency:  4.17 ms                                                
   o   Rotational Speed:  7200 RPM                                              
   o   Media data Transfer Rate:  12.58 MB/s (maximum)                          
   o   Tag Command Queuing on all models                                        
                                                                                
   The Salesmanual entry on the 7013-J30 is less enlightening.  This is        
   the only information available besides the Systems Overview and              
   Planning that contains information on these disks.                           
                                                                                
   If you would like more information about the technology which makes          
   hot-swapping possible, I cannot offer any information beyond that            
   which is in the diagrams in the services guides for the 7013-J30,            
   7135, and the 9333 (SA23-2725-00, SY33-0181-03, and SY33-0168-02).           
   The 7135 and 9333 disk array subsystems also utilize hot-plugging            
   technology.  I searched through our local data bases, ASKQ, the              
   Announcement Letters, and the Salesmanual.  I also looked through all        
   available copies of the magazine AIXtra.                                     
                                                                                
   The 7135 and 9333 are available at AIX level 3.2.5. Therefore,               
   hot-plugging hardware technology is not dependent on 4.1.1.  The             
   SMP machines were announced at 4.1.1.                                       
                                                                                
   In general, the hot pluggable feature provides a means to swap disk          
   drives out without powering down the system.  There are no definitive        
   sources of information available to ASKQ on the design, however.             
                                                                                
   Thank you.                                                                   
                                                                                
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This item was created from library item Q678638      FFTQH                      
                                                                                
Additional search words:                                                        
AUTO AUTOMATIC DASD DISC DISKETTE FFTQH HARDWARE HOT IX JAN95 J30               
OZIBM OZNEW RISCOHW RISCSYSTEM SWAPPABLE                                       


WWQA: ITEM: RTA000054896 ITEM: RTA000054896
Dated: 10/1996 Category: RISCOHW
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