Topic
  • 4 replies
  • Latest Post - ‏2013-08-29T13:11:55Z by PittP
PittP
PittP
3 Posts

Pinned topic NMON - collecting performance data before configuration data?

‏2013-08-22T14:24:21Z |

Hi,

I'm starting different tools at the same time. All other tools start at the full hour - lets say 11:00. Although NMON has been started at the same time, Performance data collecting begins 30min later (obviously it takes 30min to collect configuration information). So all tools collected for example 11:00 to 12:00, but NMON is collecting 11:30 to 12:30 ....

Is there any chance to tell Nmon should collect peformance before configuration? Furthermore, how can i determine which configuration data takes so long?

 

Thanks,

Peter

  • Steve_ATS
    Steve_ATS
    40 Posts
    ACCEPTED ANSWER

    Re: NMON - collecting performance data before configuration data?

    ‏2013-08-22T20:15:51Z  
    • PittP
    • ‏2013-08-22T15:29:48Z

    Hi Steve,

    i'm using this command line:

    /usr/bin/topas_nmon -s 10 -c 361 -p -Y -A -d -G -w 8 -K -^ -NN -P -V -F /file.nmon

    I don't access to the system, therefore cannot do the tail think.

    Do you think, that -D "skip disk configuration" and -E "skip ESS" might help?

    TOP process should not be an issue, I thought ps is collect each interval, which is not my problem. The performance collection itself is running as expected, it just starts minutes after my expection.

    The best solution would be, that nmon collects peformance first and configuration afterwards...

     

    Thanks, Peter

    -Y will add up all the same processes with the same name. If you have 100's or more processes with the same name, that could be slow. If you have lots of VGs, you could drop -V.

    You could try -D to see if it is faster. If not, I would open a service call.

    Nothing else should take that long.

  • Steve_ATS
    Steve_ATS
    40 Posts

    Re: NMON - collecting performance data before configuration data?

    ‏2013-08-22T15:01:07Z  

    What is the command line you are using to start nmon?

    If configuration information is taking that long, you can run ps and see if an AIX command is being executed in the background. You could also try 

    tail -f [my_nmon_recording] and see what area of the recording it is in.

    I would guess the slowest things are:

    BBBC tab file system collection

    BBBP tab lsconf output

    Top process information, ps api is notoriously slow. If you are collect a lot of top processes, you could turn that off and see if it is faster.

  • PittP
    PittP
    3 Posts

    Re: NMON - collecting performance data before configuration data?

    ‏2013-08-22T15:29:48Z  
    • Steve_ATS
    • ‏2013-08-22T15:01:07Z

    What is the command line you are using to start nmon?

    If configuration information is taking that long, you can run ps and see if an AIX command is being executed in the background. You could also try 

    tail -f [my_nmon_recording] and see what area of the recording it is in.

    I would guess the slowest things are:

    BBBC tab file system collection

    BBBP tab lsconf output

    Top process information, ps api is notoriously slow. If you are collect a lot of top processes, you could turn that off and see if it is faster.

    Hi Steve,

    i'm using this command line:

    /usr/bin/topas_nmon -s 10 -c 361 -p -Y -A -d -G -w 8 -K -^ -NN -P -V -F /file.nmon

    I don't access to the system, therefore cannot do the tail think.

    Do you think, that -D "skip disk configuration" and -E "skip ESS" might help?

    TOP process should not be an issue, I thought ps is collect each interval, which is not my problem. The performance collection itself is running as expected, it just starts minutes after my expection.

    The best solution would be, that nmon collects peformance first and configuration afterwards...

     

    Thanks, Peter

  • Steve_ATS
    Steve_ATS
    40 Posts

    Re: NMON - collecting performance data before configuration data?

    ‏2013-08-22T20:15:51Z  
    • PittP
    • ‏2013-08-22T15:29:48Z

    Hi Steve,

    i'm using this command line:

    /usr/bin/topas_nmon -s 10 -c 361 -p -Y -A -d -G -w 8 -K -^ -NN -P -V -F /file.nmon

    I don't access to the system, therefore cannot do the tail think.

    Do you think, that -D "skip disk configuration" and -E "skip ESS" might help?

    TOP process should not be an issue, I thought ps is collect each interval, which is not my problem. The performance collection itself is running as expected, it just starts minutes after my expection.

    The best solution would be, that nmon collects peformance first and configuration afterwards...

     

    Thanks, Peter

    -Y will add up all the same processes with the same name. If you have 100's or more processes with the same name, that could be slow. If you have lots of VGs, you could drop -V.

    You could try -D to see if it is faster. If not, I would open a service call.

    Nothing else should take that long.

  • PittP
    PittP
    3 Posts

    Re: NMON - collecting performance data before configuration data?

    ‏2013-08-29T13:11:55Z  
    • Steve_ATS
    • ‏2013-08-22T20:15:51Z

    -Y will add up all the same processes with the same name. If you have 100's or more processes with the same name, that could be slow. If you have lots of VGs, you could drop -V.

    You could try -D to see if it is faster. If not, I would open a service call.

    Nothing else should take that long.

    I was able to figure out, that reading the disk configuration took almost 30 mins. Skipping this part by using -D did the trick.

    -Y will only have impact during the performance measurement, but this was never an issue.

     

    Thanks,

    Peter