OW29186: MODIFY NET,VTAMOPTS,CSALIMIT=0 DOES NOT RESET VALUE TO NOLIMIT

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Customer set the MVS CSA maximum size in IEASYS00 (GDACSASZ). In
  VTAM startup they did not code parm CSALIMIT. It will default to
  the system CSA limit size. Using the modify command the customer
  can raise the VTAM CSALIMIT parm past the MVS system maximum
  which they should not be able to do. Also, according to the VTAM
  Resource Definition Reference manual, if they set the CSALIMIT
  value to 0 or use the command F net,VTAMOPTS,CSALIMIT=0 then the
  value will be set to NOLIMIT. This is incorrect. In both cases
  the value for ATCMXCSA should not be set to more than GDACSASZ.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All who use the CSALIMIT Start Option.       *
  ****************************************************************
  * PROBLEM DESCRIPTION: The CSALIMIT Start Option is allowed    *
  *                      to default when VTAM is started.  A     *
  *                      D NET,BFRUSE shows that the value is    *
  *                      set to something other than NOLIMIT.    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  When the CSALIMIT Start Option is not specified the VTAM
  Resource Definition Reference says that it should default to
  NOLIMIT.  But when the CSALIMIT is displayed (via D NET,BFRUSE
  or D NET,VTAMOPTS,OPT=CSALIMIT) a value other than NOLIMIT is
  displayed.
  
  Function was added in VTAM 4.4 to limit CSALIMIT to at most 90%
  of the CSA/ECSA defined to the system.  However, this was not
  documented in the VTAM publications.  Furthermore, there were a
  few errors in the added code.
  
  First of all, F VTAM,VTAMOPTS,CSALIMIT=0 results in message
  IST495I indicating CSALIMIT was now set to NOLIMIT.  However,
  D NET,VTAMOPTS,OPT=CSALIMIT results in message IST1189I which
  indicates a number for CSALIMIT instead of NOLIMIT.  The two
  messages should be consistent.
  
  Second, the intent of the function was to never let CSALIMIT
  get set to a value larger than the 90% system CSA limit.  But
  the code had a bug which allowed values much larger to be set.
  

Problem conclusion

• VTAM now allows CSALIMIT to be set no larger than the system CSA
  limit (90% of system CSA + ECSA).  For CSALIMIT in messages
  IST495I, IST1310I, and IST449I, NOLIMIT is no longer used (the
  actual value is displayed instead).
  
  The following publication changes are needed:
  
  VTAM 4.4 Messages (GC31-8368-00)
  --------------------------------
  Under message IST449I make the following changes to include
  message IST1667I:
  
    IST449I limitname = csa, CURRENT = current, MAXIMUM = maxlevel
    IST790I MAXIMUM type USED = maxK
    IST1667I SYSTEM CSA LIMIT = sys_csa_limit
     .
     .
     .
  
   IST1667I
  
   sys_csa_limit is the maximum amount of system CSA that VTAM
   will use.  It is derived by taking the total amount of CSA
   and ECSA defined in the system and multiplying by .9 (in other
   words, VTAM will never use more that 90% of the total CSA for
   the system).  See VTAM Resource Definition Reference, Start
   Options, CSALIMIT for more information on how the system CSA
   limit relates to the CSALIMIT Start Option.
  
  Under message IST495I make the following changes for messages
  IST1665I and IST1666I:
  
   Explanation: VTAM issues this message when one of the following
   occurs:
  
    The operator entered the MODIFY TRACE,TYPE=VTAM command.  The
    value specified on the SIZE operand of the command was less
    than the internal trace table default size of 50 pages.
  
    The operator entered a MODIFY VTAMOPTS,CSALIMIT or a MODIFY
    CSALIMIT command and the value specified was above the system
    CSA limit or was 0.  This message is part of a group of
    messages.  The first message is either IST1665I or IST1666I.
    See the explanation of the first message in the group for a
    complete description.
  
    The operator entered the CSALIMIT start option and the value
    specified was above the system CSA limit.  This message is
    part of a group of messages.  The first message is IST1665I.
    See the explanation of the first message in the group for a
    complete description.
  
    The operator entered a MODIFY VTAMOPTS,CSALIMIT, MODIFY
    VTAMOPTS,CSA24, or a MODIFY CSALIMIT command, and VTAM
    processed it successfully.
  
    type is one of the following:
  
      SIZE, which indicates the default size of the VTAM internal
      trace table in pages.
  
      CSALIMIT, which indicates total CSA.
  
      CSA24 LIMIT, which indicates CSA below 24-bit addressable
      storage.
  
    value is one of the following:
  
      If this message is in response to a MODIFY TRACE command,
      value is the default size of the internal trace table in
      pages and is always 50.
  
      If type is CSALIMIT and the specified value was 0 or was
      above the system CSA limit, value is set to the system CSA
      limit (see VTAM Resource Definition Reference, Start
      Options, CSALIMIT for more information.)
  
      If type is CSA24 LIMIT and the specified value was 0, value
      is NO LIMIT.
  
      Otherwise, value is the value specified on the command in
      kilobytes.
  
   System Action: If this message is in response to a MODIFY TRACE
   command, the value specified on the SIZE operand is ignored,
   and the internal trace table size is set to 50 pages.  If this
   message is in response to a MODIFY VTAMOPTS command for
   CSALIMIT or CSA24, or a MODIFY CSALIMIT command, VTAM's usage
   of CSA will be limited to value.
  
   Operator Response: None.
  
   Programmer Response: None.
  
  Add message IST1665I:
  
   IST1665I CSALIMIT VALUE value EXCEEDS SYSTEM CSA LIMIT
  
   Explanation: This message is the first in a group of messages
   that VTAM issues during start processing or in response to a
   Modify VTAMOPTS,CSALIMIT or Modify CSALIMIT command when the
   value specified for CSALIMIT is above the system CSA limit.
   See VTAM Resource Definition Reference, Start Options,
   CSALIMIT for more information about the system CSA limit.  A
   complete description of the message follows.
  
    IST1665I CSALIMIT VALUE value EXCEEDS SYSTEM CSA LIMIT
    IST1666I SYSTEM CSA LIMIT WILL BE USED FOR CSALIMIT
    IST495I type HAS BEEN SET TO value
  
   IST495I
  
   type is CSALIMIT.  value is the value to be used for CSALIMIT,
   expressed in kilobytes.
  
   IST1665I
  
   value is the value specified (but rejected) for the CSALIMIT.
  
   System Action: Processing continues with CSALIMIT set to the
   system CSA limit.
  
   Operator Response: Save the system log for problem
   determination.
  
   Programmer Response: Check the value specified for CSALIMIT in
   the start list, on the start command, or via Modify command.
   Use D NET,BFRUSE command if needed to see what the system CSA
   limit is.
  
  Add message IST1666I:
  
   IST1666I SYSTEM CSA LIMIT WILL BE USED FOR CSALIMIT
  
   Explanation: There are two ways this message can be issued:
  
    This message is part of a group of messages that VTAM issues
    during start processing or in response to a Modify VTAMOPTS,
    CSALIMIT or Modify CSALIMIT command when the value specified
    for CSALIMIT is above the system CSA limit.  The first message
    in the group is IST1665I.  See the explanation of that message
    for a full description.
  
    This message is the first in a group of messages that VTAM
    issues in response to a Modify VTAMOPTS,CSALIMIT or Modify
    CSALIMIT command when the value specified for CSALIMIT is 0.
    See VTAM Resource Definition Reference, Start Options,
    CSALIMIT for more information about the system CSA limit.  A
    complete description of the message follows.
  
    IST1666I SYSTEM CSA LIMIT WILL BE USED FOR CSALIMIT
    IST495I type HAS BEEN SET TO value
  
   IST495I
  
   type is CSALIMIT.  value is the value to be used for CSALIMIT,
   expressed in kilobytes.
  
   System Action: Processing continues with CSALIMIT set to the
   system CSA limit.
  
   Operator Response: None.
  
   Programmer Response: None.
  
  Add message IST1667I:
  
   IST1667I SYSTEM CSA LIMIT = sys_csa_limit
  
   Explanation: This message is part of a group of messages that
   VTAM issues in response to a DISPLAY BFRUSE command.  The first
   message in the group is IST449I.  See the explanation of that
   message for a full description.
  
  VTAM 4.4 Operation (SC31-8372-00)
  ---------------------------------
  DISPLAY BFRUSE Command needs the following changes:
  
   Resulting Display, For VTAM's common service area (CSA),
   including 24-bit and 31-bit addressable storage, add
  
    - The system CSA limit (90% of the total 24-bit and 31-bit
      CSA defined to the system).
  
   Examples, in each display which includes message IST790I,
   just after IST790I add
  
    IST1667I SYSTEM CSA LIMIT = 1887436K
  
  MODIFY CSALIMIT needs the following changes:
  
   Operands, CSALIMIT=value, 0, should now read
  
    when OPTION=BELOW specifies that no limit is enforced on the
    amount of CSA used by VTAM.  When OPTION=TOTAL specifies the
    maximum amount of CSA used by VTAM is to be set to the system
    CSA limit.  See "DISPLAY BFRUSE" to find out what the system
    CSA limit is for your system.
  
  VTAM 4.4 Resource Definition Reference (SC31-8377-00)
  -----------------------------------------------------
  Start Options, CSALIMIT, needs the following changes:
  
   Second paragraph, last sentence, should now read
  
    The F operand of this command allows you to force the value
    specified to be used as the CSA usage limit even though VTAM
    is currently using more CSA.  If the operator forces a lower
    limit to take effect, the operator is prevented from using
    VTAM commands until the CSA usage falls below the specified
    limit, because CSA storage is needed to process all VTAM
    operator commands except HALT CANCEL.  If the CSA usage
    does not fall below the specified CSA limit, VTAM must be
    canceled and restarted with a more appropriate CSALIMIT
    value specified.
  
   Notes, 1, should now read
  
    If the number you code is greater than the system CSA limit
    (90% of CSA + ECSA defined in the system) CSALIMIT is set to
    the system CSA limit (which is the default).  See VTAM
    Operations, DISPLAY BFRUSE, for information on displaying
    the system CSA limit.
  
   CSALIMIT=0 should now read
  
    specifies that the maximum amount of CSA storage to be used
    by VTAM is the system CSA limit.  See VTAM Operations,
    DISPLAY BFRUSE, to find out what the system CSA limit is
    for your system.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UW42676

Modules/Macros

• ISTATCVT ISTCFCML ISTCFCMM ISTCICMS ISTCICPR
  ISTCICPS ISTCIPRM ISTINCNO ISTNOCDB ISTNOCDO ISTNOCMV ISTNOCPR
  ISTVTMEU MSG1650
  

Fix information

• Fixed component name

  VTAM V4 MVS/ESA

• Fixed component ID

  569511701

Applicable component levels

• R401 PSY UW42676

     UP97/11/06 P F711

Fix is available

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