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  • 1.  lrubucket sizing recommendations

    Posted Wed May 14, 2008 11:46 AM

    Originally posted by: SystemAdmin


    Howdy,

    I have a database system running 40GB of memory. I'm not doing a whole lot of paging, but I do have a lot of activity on scanning (sr column from vmstat). I know this can be affected by the value of lrubucket in vmo, and I realize for the optimal setting I will need to tune and test. In looking for some best practice recommendation for this setting, the only info I find is just the repeated information from the lrubucket definition which states that systems with "large amounts of memory" (which is never defined, but I consider 40GB to be a pretty substantial amount) can reduce scanning by increasing the value of lrubucket. All of the examples show increasing the bucket size from the default of 512 MB to 1GB.

    Does anyone have any more insight into this parameter? Is there any sort of formula like if you have X amount of memory then lrubucket should be Y? Does anyone know if there is a diminishing point of return or a point where making the value too large could have a negative effect on performance?

    Thanks for your input.

    Message was edited by: Victor_S


  • 2.  Re: lrubucket sizing recommendations

    Posted Wed June 11, 2008 11:59 AM

    Originally posted by: SystemAdmin


    I'm giving this a bump to see if anyone can give some input.