DX Unified Infrastructure Management

  • 1.  CDM memory definition

    Posted Mar 22, 2019 01:19 PM

     

    Hi All,

    We have looked at the cdm probe pdf's and was looking at "memory usage", and "physical memory usage" defined:

     

    Memory Usage
    (MB)
    QOS_MEMORY_USAGE Megabytes Total memory
    usage in megabytes

     

    Physical Memory
    (MB)
    QOS_MEMORY_PHYSICAL Megabytes The size of the
    physical memory
    used on the
    system in
    megabytes.
    Note: For this
    metric, the buffer
    cache will be
    subtracted from
    physical memory
    value if the key
    mem_buffer_used
    is set as No. This
    support is added
    for Linux, AIX,
    Solaris and HPUX
    platforms

     

    Can someone please tell me in common laymans terms what the difference is between the two? Its confusing when the customer are looking at both and getting two different readings.

     

    TIA



  • 2.  Re: CDM memory definition

    Posted Mar 22, 2019 02:31 PM

    My understanding is that QOS_MEMORY_USAGE reflects the total amount of "memory" used. In this context, since pretty much every system today has a virtual memory model, this is the combination of physical memory, swap file, page file, mapped executable, etc that contributes to the total amount of "stuff" you can have active. More simply it can be thought of as the combination of bytes of physical memory used and bytes of page file used combined.

     

    QOS_MEMORY_PHYSICAL should be a number that represents the used size of just the physical RAM.

     

    So for instance, if you had a server that had a pagefile/swapfile size of 0 then these two values should be the same.

     

    MEMORY_USAGE should also always be the same as MEMORY_PHYSICAL or larger. 

     

    Or maybe a different way of looking at it is that MEMORY_PHYSICAL + MEMORY_SWAP = MEMORY_USAGE

     

    That is of course assuming I'm correct....