Clarification on DISK CONFIGURATION

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Hi guys,

I'm on OS400 V4R5M0, AS/400 9406-510 2144, with current CUM.

Need some clarification, education AND/OR suggestion(s) on my system disk 
configuration.

I have 2 ASP (ASP 1 is Mirrored and Raided) with a total of 173.1 Gig and 90% 
threshold.
My system ASP is 57.19Gig with 87.4692% USED.  I think the only unit MIRRORED 
in this ASP is UNIT 1.
ASP 2 is 115.92Gig with 82.49% USED. I think this ASP is totally RAIDED.
The protection column for both ASPs shows all "DEVICE PARITY" except for Unit 1 
in ASP1 that shows "CONTROLLER".

                                                                        
----Protected---  ---Unprotected--
 ASP  Unit   Type Model  Threshold  Overflow       Size  %Used      Size  %Used
   1                                        90%    No            57197 87.47%   
       0  0.00%
           1      6606  030                                        1967 100.00  
         0  0.00%
           1      6606  030                                        1967 100.00  
         0  0.00%
           2      6607  074                                        3145 89.78%  
        0  0.00%
           3      6607  074                                        3145 87.01%  
        0  0.00%
           4      6607  070                                        4194 86.78%  
        0  0.00%
           5      6607  070                                        4194 86.78%  
        0  0.00%
           6      6607  074                                        3145 86.79%  
        0  0.00%
           7      6607  074                                        3145 87.77%  
        0  0.00%
           8      6607  070                                        4194 86.79%  
        0  0.00%
         19      6713  072                                        7516 86.78%   
       0  0.00%
         20      6713  072                                        7516 86.78%   
       0  0.00%
         21      6713  072                                        7516 86.78%   
       0  0.00%
         22      6713  072                                        7516 86.78%   
       0  0.00%
   2                                        90%    No          115964 82.49%    
      0  0.00%
           9      9337  59C                                       8589 82.75%   
       0  0.00%
         10      9337  59C                                       8589 82.42%    
      0  0.00%
         11      9337  59C                                       8589 82.47%    
      0  0.00%
         12      9337  59C                                       8589 82.51%    
      0  0.00%
         13      9337  59C                                       8589 82.31%    
      0  0.00%
         14      9337  59C                                       8589 82.31%    
      0  0.00%
         15      9337  59C                                       8589 82.60%    
      0  0.00%
         16      9337  59C                                       8589 82.59%    
      0  0.00%
         17      9337  59C                                       8589 82.61%    
      0  0.00%
         18      9337  59C                                       8589 82.60%    
      0  0.00%
         23      6713  072                                       7516 82.49%    
      0  0.00%
         24      6713  072                                       7516 82.35%    
      0  0.00%
         25      6713  072                                       7516 82.42%    
      0  0.00%
         26      6713  072                                       7516 82.31%    
      0  0.00%


QUESTIONS:
==========
1.    Can this configuration be improved without any additional hardware and 
system disruption?
2.    My disk arm AVG % busy < 10% is this a good number and better usage of 
these ARMS?
3.    My MIRRORED disks are at 100%, if this is bad what can I do to improve?
4.    If I decided to upgrade to V5, will the MIRRORED disk be sufficient to 
accommodate the OS?
5.    Can I safely say that my current OS is contained in my MIRRORED disk?
6.    What other suggestions or comments would you give with this configuration?
7.    How do my both ASPs get used in terms of internal code libraries and 
other libraries?

Thanks for all of your input.

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