patch details: MPEMXT4C

Patch Description
     Large Disk: SSM changes for disk space allocation and accounting

SR Number:
     8606-391171     8606-340906

This patch is dependent upon: None

General Release Text
Known Conflicts                                                                 
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Not applicable                                                                  
                                                                                
Patch-to-Patch Dependencies                                                     
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The following patches address various aspects of Large Disk/Files               
Support enhancements.  Although these patches are not truly dependent           
upon each other, the complete set of fixes will be available if they            
are installed as a group.                                                       
                                                                                
MPEMXT1 - Large Disk: FSCHECK SYNCACCOUNTING fix for HFS files                  
MPEMXT3 - Large Disk: limit maximum SCSI disk size to 1/2 TB                    
MPEMXT4 - Large Disk: SSM changes for disk space allocation and                 
          accounting                                                            
MPEMXT7 - Large Disk: Discfree changes to correct sector counts                 
MPEMXU3 - Large Disk: REPORT "FORMAT=LONG" enhancement                          
          (Note: MPEMXU3 includes patch MPEMXT2 which is another                
           Large Disk/Files patch.  MPEMXT2 provides changes to the             
           ALTACCT, NEWACCT, ALTGROUP, NEWGROUP commands.)                      
MPEMXU6 - Large Disk: CATALOG.PUB.SYS changes for CIERR messages                
MPEMXU7 - Large Disk: CICAT and CICATERR.PUB.SYS changes                        
                                                                                
External Symptoms, Cause, Fix Description                                       
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By default MPE/iX should allocate disk space from the volume set member         
with the highest PERCENTAGE of free space.  In this case it has been            
found that if very large disks are added to a volume set (> 87 GB) MPE          
will not always use them EVEN if they are nearly empty.                         
                                                                                
Note this is NOT a problem if the disk is the sole member of a volume           
set.  Or if ALL disks are the same size.   It is only a problem when            
there is a mix of "small" and very large disks (< 87 and > 87 GB) . .           
                                                                                
The problem is due to an overflow in calculations using 32 bit values           
-- the fix is to perform the calculation in a way that prevents an              
overflow and thus produces the correct percentage of used/free disk             
space.                                                                          
                                                                                
Customer Environment Changes                                                    
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Not applicable                                                                  
                                                                                
Hardware Dependencies                                                           
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Not applicable                                                                  
                                                                                
Software Product/Application Dependencies                                       
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Not applicable                                                                  
                                                                                
Product Version Information                                                     
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See filename information for specific version changes for each module.          
                                                                                
Dump Analysis                                                                   
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Not applicable                                                                  

OS Release VUF: C.65.00

Supersedes:
     (0) MPEMX38 C  (Current General Release patch)

Criticality:
     (1) The system could experience a System failure without the patch.

Update Required: Yes

This page last updated on Mon, Mar 10, 2008