CODEWITHSUNDEEP
ibm-midrange
Cryptographic_ICE
Cryptographic_ICE

Reputation: 619

iSeries memory utilization details or reports

I would like to make a change to the mysql server we are running on our iseries server. The change will increase the amount of memory mysql will use. Before I make this change I would like know how much memory do we have in our iseries? Roughly how much would be available at any given point? I have seen the WRKSYSSTS screen but I’m not sure how to read any info the information on IBM’s website has not been any help either. We are running V7R1

Just to clarify I'm not going to be changing iseries memory allocation or pools. I'm going to be changing MySQL settings that could result in the mysql processes consuming more memory then they currently are. If I make a change that causes mysql to use more memory than is available swapping could occur and I would be worse off.

Upvotes: 4

Views: 5516

Answers (1)

Buck Calabro
Buck Calabro

Reputation: 7648

% CPU used . . . . . . . :        1.2    Auxiliary storage:                    
Elapsed time . . . . . . :   00:00:01      System ASP . . . . . . :     2512 G 
Jobs in system . . . . . :      22701      % system ASP used  . . :    62.9081 
% perm addresses . . . . :       .108      Total  . . . . . . . . :     2512 G 
% temp addresses . . . . :       .215      Current temporary used :    40805 M 
                                           Peak temporary used  . :    42907 M 

Type changes (if allowed), press Enter.                                        

System    Pool    Reserved    Max   -----DB-----  ---Non-DB---                 
 Pool   Size (M)  Size (M)  Active  Fault  Pages  Fault  Pages                 
   1     1599.71    826.38   +++++     .0     .0     .0     .0                 
   2    26424.60      9.43     276     .0     .0     .9     .9                 
   3      314.87      <.01       9     .0     .0     .0     .0                 
   4     3148.79       .50     386     .0     .0   10.8   24.3                 

                                                                        Bottom

The numbers at the top right (Auxiliary storage) are for disk. The numbers in the various pools are RAM. You need to add them up to come up with a total. There are rounding issues, but the posted example machine has 32GB RAM installed.

Having explained that, I strongly caution you against tinkering with your memory pools until you have read and understood the Work Management Guide There are several interlocking and overlapping changes that you will probably need to make and these changes should not be made blindly. The rule for performance management is to measure, change one variable and measure again. WRKSYSSTS, WRKSBS, WRKSYSACT, and WRKDSKSTS can all help measure the workload. Read the Guide.

Upvotes: 4

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