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  • 1.  Inquiry regarding startstats -interval for SVC and V7000

    Posted Mon July 29, 2024 11:00 PM

    Dear,

    The customer wants to monitor the performance of SVC and V7000 through a solution called Arxview.
    In Arxview, there is a guide that change "startstats -interval 5".
    So, I executed the startstats -interval 5 command to change the interval to 5 minutes, but after a while, the interval was restored to 1 minute. 
    We would like to continuously collect performance in 5 minute increments, so please provide guidance on this.

    Thanks.



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    SUNG EUN KIM
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  • 2.  RE: Inquiry regarding startstats -interval for SVC and V7000

    Posted Tue July 30, 2024 04:14 AM

    Could it be possible that Arxview resets the interval to 1 again after a while? You could check this in the audit log (cli: catauditlog)



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    TMasteen
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    Original Message


  • 3.  RE: Inquiry regarding startstats -interval for SVC and V7000

    Posted Thu August 01, 2024 04:22 AM

    Keep in mind, that the in-memory auditlog will be dumped to a file on the boot drive every 500 entries.

    That said, if for example the startstats command was the one with sequence number 1499, auditlog will be dumped to file after command sequence number 1500, so it would not be visible any longer through cli catauditlog. 

    Anyhow, this was just to remind you of this behaviour, so you aren't too surprised if not seeing command history in the first place.



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    Best regards, 

    Christian Schroeder
    IBM Storage Virtualize Support with Passion
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    Original Message


  • 4.  RE: Inquiry regarding startstats -interval for SVC and V7000

    Posted Tue August 13, 2024 06:25 AM

    Hello,
    you should not need to worry about this. The statistics are counters, just like your utility meters (water, gas, electric, ...), which means that always increase. Setting the interval to 5 minutes, simply means, every 5 minutes the counters are written to the stat files.

    If another application needs to have the statistics in 1 minute interval that will not interfere with your other application that needs 5-min intervals. Let's say the application with the 5 min setting is collecting the files at :00, :05,  :10, .... The value in the files will be the value of the difference counters at that time, and it doesn't matter at :10 when the previous statistics files were created. The values in the stat files are absolute values in that sense, not delta values, so the interval doesn't really matter.

    There are only two aspects that are influenced buy the interval:

    1. How long the files go back in time: there are (I believe) only 16 "versions" of the files, so setting a 1 minute interval means you can only see 16 minutes in the past, when you get all the files like during a support case, with 5 minutes this would be 80 minutes, but realistically it doesn't matter
    2. The maximum values: While 1 minute intervals allows for better capturing of maximum values, 1 minute is still a pretty long time, and with 5 min intervals any peak is even more smoothed out. This would be something visible in your application and different intervals are not interfering with each other.
      • Note, there are some values in the stat files that are already max xyz values, and those will be a bid skewed for the application using the 5min intervals, because that application will collect every 5 minutes a files, which doesn't have the max value of the 5 min period, instead that file will include the max value of the last 1 minute of the period. 
        However in practical use of the data, this doesn't have a significant impact: Remember  Spectrum Control is running with 1 min intervals (for selected IBM systems) but Storage Insights is using 5 min intervals in many installations, and there is no issue with this.

    I hope this helped

    Regards, Markus



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    Markus Standau
    Offering Leader for FlashSystems and SVC
    IBM
    Walldorf
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    Original Message