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2 replies Latest Post - ‏2012-11-13T17:08:20Z by Steve_ATS
SystemAdmin
SystemAdmin
2402 Posts
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Pinned topic How to recognize swapping ?

‏2012-11-12T21:43:19Z |
Hello,

we are quite new in AIX world. We are trying to migrate some of our software from Solaris to AIX.
During our benchmarks we are monitoring are system. But I am not sure how can I recognize if
AIX is swapping (using sar) ?
Updated on 2012-11-13T17:08:20Z at 2012-11-13T17:08:20Z by Steve_ATS
  • The_Doctor
    The_Doctor
    5 Posts
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    Re: How to recognize swapping ?

    ‏2012-11-13T16:01:33Z  in response to SystemAdmin
    My guess is you are really wondering about how much PHYSICAL paging is going on.

    AFAIK, SAR really isn't the best tool for that.

    I'd be looking initially at commands similar to :
    
    --> vmstat -wIt 1 30   OR   --> topas
    

    if I wanted some quick insight into what was taking place.
  • Steve_ATS
    Steve_ATS
    40 Posts
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    Re: How to recognize swapping ?

    ‏2012-11-13T17:08:20Z  in response to SystemAdmin
    In vmstat, physical paging is pi/po. AIX 6.1 should not physically page (other than small backing segments) until you reach 97% computational (working) memory. Otherwise, you need an APAR. vmstat -v, svmon, nmon and topas will report percentages or totals of memory types.

    Your first complaint will be that all the memory is used in AIX. You will need to familiarize yourself with the concepts of computational memory vs file cache. You cannot look at memory "free" and have any idea what is going on:

    http://www.ibm.com/developerworks/aix/library/au-vmm/

    computational rate is the only thing that really matters.