4. EXCEPTIONS › 4.3 Detailed Exception Descriptions › 02153: Percent Control Unit Busy Exceeds Max

02153: Percent Control Unit Busy Exceeds Max

FILE: Logical Control Unit Activity File
SAS FILE NAME: DAYS.SCPLCU01
SOURCE LOCATION: prefix.MICS.USER.SOURCE(DYRMFEXC)

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

PURPOSE:  Identify overcommitted physical control units.

RATIONALE:  A high percentage I/O operations deferred for any
reason indicates a possible I/O bottleneck, resulting in
lower throughput or elongated response times in I/O-sensitive
online systems.  This exception identifies LCUs with
excessive numbers of I/Os deferred due to physical control
unit busy conditions.

DEFINITION:  This exception is detected when the percent of
I/O operations deferred due to physical 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:

/* ***********************************************
**  02153 PERCENT CONTROL UNIT BUSY EXCEEDS MAX **
*********************************************** */
IF LCUPCCUB GT percent
 THEN DO;
  EXCCODE='02153'; SEVERITY='I'; MGMTAREA='PERFORMANCE';
  EXCDESC1='PERCENT CONTROL UNIT BUSY EXCEEDS MAX';
  EXCDESC2='BUSY=' !! PUT(LCUPCCUB,5.1) !!
       '%, LCUID=' !! LCUID;
  LINK HIT;
END;

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

percent - The maximum percent of I/O requests deferred due to
physical control unit busy is specified.  A threshold of 15
percent would appear as:

LCUPCCUB GT 15