Topic
4 replies Latest Post - ‏2013-06-28T11:35:12Z by matekamoris
JLGuyot
JLGuyot
4 Posts
ACCEPTED ANSWER

Pinned topic nmon analyser and SEA

‏2013-06-26T15:53:59Z |

Hi,

i'm trying to use nmon analyser to graph the usage of my SEA.

The data is in the nmon file, but nmon analyser don't show them.

Is there a way to see them, or a future plan on that ?

Thx in advance for this great tool.

  • Steve_ATS
    Steve_ATS
    40 Posts
    ACCEPTED ANSWER

    Re: nmon analyser and SEA

    ‏2013-06-27T00:47:15Z  in response to JLGuyot

    You're using the -O option and running nmon on the VIOS? Have a recent level of analyser (I think it worked on the version before 34A)? VIOS level?

    • JLGuyot
      JLGuyot
      4 Posts
      ACCEPTED ANSWER

      Re: nmon analyser and SEA

      ‏2013-06-27T07:46:42Z  in response to Steve_ATS

      Hi Steve,

      I have 1300 disks on the machine and the excel results has tons of tabs and i just forgot to watch further in the tabs list....

      I got the information i need in SEA tab, thx for the heads up :)

  • JLGuyot
    JLGuyot
    4 Posts
    ACCEPTED ANSWER

    Re: nmon analyser and SEA

    ‏2013-06-27T11:50:38Z  in response to JLGuyot

    Actually i still have a problem.

    I have 2 SEA and each SEA shows the same value for read and write.

    I have difficulties trusting the metrics taken...

  • matekamoris
    matekamoris
    3 Posts
    ACCEPTED ANSWER

    Re: nmon analyser and SEA

    ‏2013-06-28T11:35:12Z  in response to JLGuyot

    Hi Jean-Luc,

     

    As stated by user seroyer and jklotz in this post : https://www.ibm.com/developerworks/community/forums/html/topic?id=77777777-0000-0000-0000-000014874176

     

    My educated guess of similar statistics on SEA adapters is that it reflects what the SEA is doing : it acts like a switch port, and receives some frames on one side (partitions virtual adapters for example) that it transmits to the other side (the physical LAN in my example).

    Therefore, unless some frames are discarded, you should have the same amount of data on each side.

     

    The graph you produced is plausible and even likely if you are using SEA (or otherwise have a trunk adapter). If you have an active trunk adapter and at least one other active adapter, then every frame that is transmitted will be recieved by one (or more) virtual adapters on the same VLAN (assuming your physical switch configuration is sane).

    You can also end up with a graph that looks similar to that, but where the rx side is a bit larger than the tx side if you have lots of broadcast or multicast traffic. In that case, each broadcast/multicast frame transmitted can be received by all other adapters on the VLAN (depending on multicast filtering), which would result in each receiving adapter incrementing its rx but the transmitter only incrementing its tx once.

     

    Having same values for rx and tx on an SEA seems to be normal.

    Best.

    Benoit.