Below are sample output, the script gathers SCSI IO statistics given a sampling
interval and displays the summary ouptut in histogram format.  The script takes
1 argument which is sampling interval in seconds.

The left column of the histogram 'value' output is the latency time in milli-seconds
and the right 'count' are the number of IO commands completed.
 
# scsi-latency.d 5   (5 being sample interval in seconds).
        sdbz
           value  ------------- Distribution ------------- count
              -1 |                                         0
               0 |@@@@@@@@@@@@@@@@@@@@@@                   16616
               1 |@@@@@@@@@@@@@@@@                         12411
               2 |@@                                       1479
               4 |                                         229
               8 |                                         10
              16 |                                         0
    (ms)
        sdef
           value  ------------- Distribution ------------- count
              -1 |                                         0
               0 |@@@@@@@@@@@@@@@@@@@@@@@@@@               29766
               1 |@@@@@@@@@@@@                             14042
               2 |@                                        1073
               4 |                                         186
               8 |                                         2
              16 |                                         0
    (ms)

Below is a sample of abnormally higher latency of IO completion.

# scsi-latency.d 5
       2022 Oct 21 15:49:16
        =======================================================
        sddb                                 7:0:2:229
           value  ------------- Distribution ------------- count
              -1 |                                         0
               0 |@@                                       2
               1 |                                         0
               2 |@@@@@                                    5
               4 |@                                        1
               8 |@@                                       2
              16 |                                         0
              32 |                                         0
              64 |                                         0
             128 |                                         0
             256 |                                         0
             512 |                                         0
            1024 |                                         0
            2048 |                                         0
            4096 |                                         0
            8192 |                                         0
           16384 |@@@@@@@@@@@@@@@@@@@@@                    20
           32768 |@@@@@@@@@                                9
           65536 |                                         0
    (ms)
    ========================================================

