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Average Disk sec/Write and Average Disk sec/Read values are zeros RRS feed

  • Question

  • The values of Average Disk sec/Write and Average Disk sec/Read values are mostly zeros in generated reports. I can see some 0.01 and 0.02 but the most are zeros. Although disk bytes read/s and disk bytes write/s  are large numbers. It seems like an rounding error of Excel or MAP Toolkit or SQL Express DB. There must be numbers like 0.00012345 but because of rounding to two digits after point I can see only zeros. How can I get real values?
    Thursday, June 10, 2010 5:26 PM

All replies

  • The values get rounded off for display purposes. But, the database has the actual averages of samples collected. You can look at dbo.performance_logical_disk table for the actual data and columns in this table are named according to the underlying perf counter.

    -MAP Team

    Tuesday, June 15, 2010 11:16 PM
  • Strange feature. This values are almost always <0.005 and they are important for counting of Read IOPS and Write IOPS.

    There is very nice tool "HP Sizer For Microsoft Windows Server 2008 R2 Hyper-V". It uses this values from MAP Tool performance report for counting IOPS. Because of this stupid rounding this tool is making wrong configuration proposals.

    Thursday, June 17, 2010 1:10 PM
  • OK, I can see this values in a dbo.performance_logical_disk table but I cannot see server's name in this table. How can I select disk IOPS information for server MyFileserver1 for example?
    Saturday, June 26, 2010 7:44 PM
  • SELECT

     

    dbo.GetDeviceNameForDisplay(device_number), * FROM dbo.performance_logical_disk

    There will be multiple rows per computer representing multiple samples and multiple disk instances (multiple samples denoted by the index column and multiple disk instances denoted by the instance column).  You'll have to decide how to aggregate those.

    Monday, June 28, 2010 3:38 PM