Port Object Commandswww.3ware.com 106/cx/px set dpmstat=clear [type=ra|lct|ext]This command only applies to 9000 series SX/SE/SA controllers, except fortype=ext, which applies only to SE/SA models.This command allows you to clear the data buffers of accumulated statisticsinformation. There are two reasons to clear this data:• Once dpmstat is enabled, statistics information continues to accumulate.Eventually it can cause a buffer overflow, causing all statisticsinformation to be rendered as ####.• You wish to have fresh data, such as when switching betweenbenchmarking writes to benchmarking reads.This command clears the statistics counters of the Drive PerformanceMonitor. The optional type attribute specifies which statistics should becleared. The options are: ra for Running Average, lct for Long CommandTimes, and ext for Extended Drive Statistics. For more about these statistics,see “/cx/px show dpmstat type=inst|ra|lct|histdata|ext” on page 102.Please note that if type=ra, both the Running Average and Histogram data arecleared. If type=lct, only the Long Command Times data will be cleared. Andif type=ext, the extended drive statistics are cleared. If no type is specified,the default is the same as type=ra. Note that there are no direct commands forclearing only histogram data, or for clearing instantaneous data.Example of clearing Running Average and Histdata statistics://localhost> /c0/p3 set dpmstat=clear type=raClearing Drive Performance Monitor running average data on /c0/p3 ... Done.Please note this clears the Running Average and Histogram data.Example of clearing when I/O traffic has been stoppedIf I/O traffic to the drive has been stopped, after clearing, a subsequent requestto show the running average statistics would show all zeros.//localhost> /c0/p3 show dpmstat type=raQueue Xfer RespPort Status Unit Depth IOPs Rate(MB/s) Time(ms)--------------------------------------------------------------p3 OK u0 0 0 0.000 0Similarly, the display for Histogram data would also be all zeros.
