Avago Technologies 3ware SAS 9750-4i - Manual (Page 122)

Chapter 2. CLI Syntax Reference
114 3ware SATA+SAS RAID Controller Card CLI Guide, Version 10.0
/c x /p x set dpmstat=clear [type=ra|lct|ext]
This command only applies to 9000 series SX/SE/SA controllers, except for
type=ext, which applies only to SE/SA models and 9750 models.
This command allows you to clear the data buffers of accumulated statistics
information. 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 statistics
information to be rendered as ####.
• You wish to have fresh data, such as when switching between
benchmarking writes to benchmarking reads.
This command clears the statistics counters of the Drive Performance
Monitor. The optional type attribute specifies which statistics should be
cleared. The options are: ra for Running Average, lct for Long Command
Times, and ext for Extended Drive Statistics. For more about these statistics,
see “/cx/px show dpmstat type=inst|ra|lct|histdata|ext” on page 110.
Please note that if type=ra, both the Running Average and Histogram data are
cleared. If type=lct, only the Long Command Times data will be cleared. And
if 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 for
clearing only histogram data, or for clearing instantaneous data.
Example of clearing Running Average and Histdata statistics:
//localhost> /c0/p3 set dpmstat=clear type=ra
Clearing 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 stopped
If I/O traffic to the drive has been stopped, after clearing, a subsequent request
to show the running average statistics would show all zeros.
//localhost> /c0/p3 show dpmstat type=ra
Queue Xfer Resp
Port Status Unit Depth IOPs Rate(MB/s) Time(ms)
--------------------------------------------------------------
p3 OK u0 0 0 0.000 0
Similarly, the display for Histogram data would also be all zeros.