Topic
  • 3 replies
  • Latest Post - ‏2012-10-04T05:32:52Z by cggibbo
swarzes
swarzes
2 Posts

Pinned topic AIX 7.1/6.1 init_high_wat network tuning parameters

‏2012-09-12T11:38:12Z |
In AIX 7.1 TL1 SP5, new network tuning parameter is introduced - init_high_wat. I could not find any details (google, man pages) about this parameter and how it can be used to improve network performance.

Anyone has any idea?
Updated on 2012-10-04T05:32:52Z at 2012-10-04T05:32:52Z by cggibbo
  • IgnacioDB
    IgnacioDB
    5 Posts

    Re: AIX 7.1/6.1 init_high_wat network tuning parameters

    ‏2012-09-19T11:41:02Z  
    Hi swazes, I suppose that is not a tunning to directly improve network performance, its a tunning to prevent that peaks of network activity impacts on CPU consumption.
    I think that is the same concept of I/O pacing for network performance, using pinned memmory to support high network traffic workloads.

    Regards
  • swarzes
    swarzes
    2 Posts

    Re: AIX 7.1/6.1 init_high_wat network tuning parameters

    ‏2012-10-03T09:33:10Z  
    Thanks IgnacioDB. Is there any way to disable this parameter or init_high_wat=0 means it is disabled?
  • cggibbo
    cggibbo
    27 Posts

    Re: AIX 7.1/6.1 init_high_wat network tuning parameters

    ‏2012-10-04T05:32:52Z  
    1. no -h init_high_wat
    Help for tunable init_high_wat:
    Purpose:
    Specifies the initial high water mark value for 128K bytes bucket per cpu. If init_high_wat is set, it will pin more initial memory for internal 128K bytes bucket than default behavior.

    Values:
    Default: 0
    Range: 0 - 10
    Type: Dynamic
    Unit: %_of_thewall
    Tuning:
    The init_high_wat attribute represents a percentage of the thewall per cpu. For example, if init_high_wat is set to 2, thewall is 8 gigabytes, and it has 4 logic cpus, the number of 128 kilobytes in size per cpu is: ((8 * 1024 * 1024 * 1024) / 4) / (128 * 1024) = 16384. 2% of 16386 is 327. So the initial high water value for 128 kilobytes in size per cpu is 327. WARNING: This is an extremely sensitive option and can have adverse impact on your system performance if set unresaonably high. Please use extreme caution in modifying this option.