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Displaying LUN statistics on exceeding throttles

Statistics are available about I/O requests for LUNs that exceed the igroup throttle. These statistics can be useful for troubleshooting and monitoring performance.

Steps

  1. Enter the following command:
    lun stats -o -i time_in_seconds

    -i time_in_seconds is the interval over which performance statistics are reported. For example, -i 1 reports statistics each second.

    -o displays additional statistics, including the number of QFULL messages, or "QFULLS".

    Example

    lun stats -o -i 1 /vol/vol0/lun1
    system1> lun stats -o -i 1 /vol/vol0/lun1
    Read  Write Other QFull Read  Write  Average  Queue   Partner   Lun
    Ops   Ops   Ops          kB    kB    Latency  Length   Ops kB
    0    5108    0     0     0    20432   0.62    6.00      0  0   /vol/vol0/lun1
    ---
    0    7555    0     0     0    30220   0.00    5.05      0  0   /vol/vol0/lun1
    ---
    0    7535    0     0     0    30144   0.01    5.05      0  0   /vol/vol0/lun1
    ---
    0    5599    0     0     0    22396   0.38    5.08      0  0   /vol/vol0/lun1
    ---
    0    6847    0     0     0    27384   0.16    5.07      0  0   /vol/vol0/lun1
    ---
    0    7460    0     0     0    29836   0.01    5.05      0  0   /vol/vol0/lun1
    ---
    0    7461    0     0     0    29844   0.01    5.05      0  0   /vol/vol0/lun1
    ---
    0    4962    0     0     0    19848   0.64    6.00      0  0   /vol/vol0/lun1
    ---
    0    7379    0     0     0    29516   0.05    5.05      0  0   /vol/vol0/lun1
    ---
    0    7482    0     0     0    29924   0.01    5.05      0  0   /vol/vol0/lun1
    ---
    0    7416    0     0     0    29664   0.02    5.05      0  0   /vol/vol0/lun1
    

    The output displays performance statistics, including the QFULL column. This column indicates the number of initiator requests that exceeded the number allowed by the igroup throttle, and as a result, received the SCSI Queue Full response.

  2. Display the total count of QFULL messages sent for each LUN by entering the following command:
    lun stats -o lun_path

    Example

    system1> lun stats -o /vol/vol0/lun1
    /vol/vol0/lun1  (11 hours, 19 minutes, 0 seconds)
    Read(kbytes) Write(kbytes) Read Ops Write Ops Other Ops QFulls Partner Ops Partner KBytes
       488          4875956       60      1218939    84       0       83          448