4. EXCEPTIONS › 4.3 Detailed Exception Descriptions › 02703: Control Unit Busy Exceeds Max

02703: Control Unit Busy Exceeds Max

FILE: I/O Queuing Configuration File
SAS FILE NAME: DAYS.SCPIOC01
SOURCE LOCATION: prefix.MICS.USER.SOURCE(DYRMFEXC)

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

PURPOSE:  Identify overloaded control units that may be
symptomatic of I/O problems and performance degradation.

RATIONALE:  As the probability of finding a control unit busy
increases, the probability of I/O operations being delayed
also increases.  This can be a real problem if all of the
physical control units within the logical control unit are
excessively busy.

DEFINITION:  This exception is detected when the control unit
busy percentage exceeds the installation-defined maximum.
The actual percent that indicates a possible problem varies
with the I/O configuration and nature of the resources being
accessed.

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:

/* ***************************************
**  02703 CONTROL UNIT BUSY EXCEEDS MAX **
*************************************** */
IF IOCPCCUB GT percent THEN DO;
  EXCCODE='02703'; SEVERITY='I'; MGMTAREA='PERFORMANCE';
  EXCDESC1='CONTROL UNIT BUSY EXCEEDS MAX';
  EXCDESC2='BUSY=' !! PUT(IOCPCCUB,5.1) !!
           '%, LCUID=' !! TRIM(LCUID) !!
           ', CHAN=' !! CHANNEL;
  LINK HIT;
END;

THRESHOLD MODIFICATION:  The user should modify the percent
value according to the following convention:

percent - The maximum percent control unit busy is specified.
A 25 percent threshold would appear as:

IOCPCCUB GT 25