4. EXCEPTIONS › 4.3 Detailed Exception Descriptions › 02103: Log Chan / LCU Delayed I/O (CU Busy) Exceeds Max

02103: Log Chan / LCU Delayed I/O (CU Busy) Exceeds Max

FILE: Logical Channel/CU Activity File
SAS FILE NAME: DAYS.SCPLCA01
SOURCE LOCATION: prefix.MICS.USER.SOURCE(DYRMFEXC)

SEVERITY: Impacting            (SEVERITY='I')
MANAGEMENT AREA: Performance   (MGMTAREA='PERFORMANCE')

PURPOSE:  Identify why logical channel or logical control
unit queuing exists.

RATIONALE:  Queuing can be caused by a control unit, channel
path busy, or device busy condition.  One of these reasons,
control unit busy, can indicate incorrect configuration of
control units in the I/O subsystem.

DEFINITION:  This exception is detected when the percent of
I/O operations deferred because of control unit busy exceeds
the installation-defined maximum.

EXCEPTION STATEMENTS:  The SAS statements identifying the
exception situation and describing the condition are stored
in the source member named in SOURCE LOCATION and are
described below:

**  02103 LCU DELAYED I/O (CU BUSY) EXCEEDS MAX
*;
IF LCAPCCUB GT percent
 THEN DO;
  EXCCODE='02103';SEVERITY='I';MGMTAREA='PERFORMANCE';
  EXCDESC1=
    'LCU DELAYED I/O (CONTROL UNIT BUSY) EXCEEDS MAX';
  EXCDESC2='DELAYED=' !! PUT(LCAPCCUB,5.1) !!
          '%, LCUID=' !! LCUID;
  END;
  LINK HIT;
END;
THRESHOLD MODIFICATION:  The user should modify the percent
value according to the following convention:

percent - The maximum percent of delayed I/O operations is
specified.  A threshold of 75 percent would appear as:

LCAPCCUB GT 75