Controls XFC's statistics collection feature(s).

1  –  TRACE

    Controls the types of events that will be recorded by XFC's trace
    facility and initializes the trace structures (to eliminate already-
    recorded events).

1.1  –  Description

    The events that can be traced are organized into five categories
    (Extent/Hash, Init/Common/Sys, Lock, LRU/Mem/MemMgt, and Read/Write),
    which correspond to the organization of the XFC software
    architecture.  Within each type, the traceable events are organized
    by level of importance.  With the /SELECT qualifier, the user can
    select events to trace by type and level-within-type.  With the /MASK
    qualifier, the user can select arbitrary (groups of) events to be
    traced.

    Format

      SET TRACE [/SELECT= | /MASK=] [/RESET]

1.2  –  Qualifiers

1.2.1    /SELECT

      /SELECT={TYPE:type, LEVEL:level}

    Allows the user to control what is traced by named
    category.  The value list should consist of paired
    type and level specifications, with the type preceding
    the level.  If a TYPE specifier is not followed by a
    level specifier, tracing for that type will be set to
    the default level.  If a LEVEL specifier is not preceded
    by a TYPE specifier, the level will be set for all types.

    The default tracing level is:
            1 - standard XFC image
            4 - MON image
            4 - DEBUG image

    An attempt to set the level above the maximum for any type
    results in a warning and the level being set to the maximum.

    The trace types and level selected in the value list of
    one instance of the /SELECT qualifier enables tracing of
    those events and disables all others.  (If multiple
    SET TRACE/SELECT commands are used, only the selections of
    the last will take effect.)

    The LOCK category has 6 possible levels (1 through 6).
    All other categories have 4 possible levels (1 through 4).

1.2.2    /MASK

      /MASK=bitmask

    Allows the user to select individual trace types by the bit
    positions in bitmask that are set to 1.  The /MASK qualifier
    is incompatible with the /SELECT qualifier.

    The bit positions are as follows:

         0 - Extent/Hash Level 1
         1 - Extent/Hash Level 2
         2 - Extent/Hash Level 3
         3 - Extent/Hash Level 4
         4 - Init/Common/Sys Level 1
         5 - Init/Common/Sys Level 2
         6 - Init/Common/Sys Level 3
         7 - Init/Common/Sys Level 4
         8 - LRU/Mem/MemMgt Level 1
         9 - LRU/Mem/MemMgt Level 2
        10 - LRU/Mem/MemMgt Level 3
        11 - LRU/Mem/MemMgt Level 4
        12 - Read/Write Level 1
        13 - Read/Write Level 2
        14 - Read/Write Level 3
        15 - Read/Write Level 4
        16 - (Reserved)
        17 - (Reserved)
        18 - (Reserved)
        19 - (Reserved)
        20 - (Reserved)
        21 - (Reserved)
        22 - (Reserved)
        23 - (Reserved)
        24 - Lock Level 1
        25 - Lock Level 2
        26 - Lock Level 3
        27 - Lock Level 4
        28 - Lock Level 5
        29 - Lock Level 6
        30 - (Reserved)
        31 - (Reserved)

1.2.3    /RESET

    Initializes the trace buffer to eliminate all already-traced
    events.