OA46493: IN Z/OS2.1 A RAS ENHANCEMENT WAS IMPLEMENTED TO ELIMINATE ABEND837-08 FOR TAPE DATA SETS.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• In z/OS2.1 a RAS enhancement was implemented to eliminate
  ABEND837-08 for tape data sets. This also, removed the ability
  to limit the number of volumes available to a Job through JCL
  or DATACLAS.
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All                                          *
  ****************************************************************
  * PROBLEM DESCRIPTION: No ability to limit the number of       *
  *                      volumes available to a job.             *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  With the V2R1 RAS enhancement, an ABEND837-08 will not appear
  after an attempt to exceed the limit set by the user's JCL
  Volume count, Vol=.
  

Problem conclusion

• Establish a behaviour similar to that seen prior to V2R1
  for dynamically-allocated tape datasets. That is, honour
  the value set in the user's JCL by VOLCNT, up to the pre-
  allocated volume limit (6,21,21+15, etc, up to 255).
  DATACLAS VOLCNT settings are honored, too. However,
  explicitly-set user JCL settings will override those
  set in DATACLAS.
  The following updates will be reflected in a future revision
  of z/OS MVS JCL Reference, in Ch. 12 DD Statement, VOLUME
  parameter, volume-count subparameter definition:
  
  volume-count
  DASD volumes cannot be removed from the drive.  Therefore the
  number of volumes for a data set is the same as the number of
  drives for the data set. This number cannot exceed 59.
  
  For a tape data set the number of volumes can be more or less
  than the number of drives.  The number of drives cannot exceed
  59. The number of volumes cannot exceed 255.  The system uses
  the unit count to determine how many tape devices to allocate.
  However, if you also specify P (for parallel mount) in the
  UNIT parameter, the system might use the value specified for
  the volume count to determine how many devices and volumes to
  allocate. See the unit-count description in  Subparameter
  definition  on page 293.
  
  Volume count and serial numbers: When the volume count is
  greater than:
       - The number of volume serials coded in the SER
  subparameter
       - The number of volume serials the system retrieved from
  the catalog
       - The number of volume serials the system retrieved from
  VOL=REF
       - The number of volume serials the system retrieved from
  a passed data set, the system can assign more volumes. If the
  volume count is smaller than the number of volume serials, the
  system ignores the volume count.
  
  If a data set may need more volumes than the number of volume
  serials coded, specify a volume count equal to the total
  number of volumes that might be used. Requesting more volumes
  in the volume count will ensure that the data set can be
  written on more volumes if it exceeds the requested volumes.
  
  Volume count for nonspecific requests: If the request is for
  a nonspecific, public volume on a direct access device, the
  system ignores the volume count and allocates the number of
  volumes in the UNIT count subparameter. If the request is
  for a nonspecific, private volume, then the system will act
  as though a volume count greater than one was coded, and
  will allocate the number of volumes given in the volume count.
  
  Volume count for system-managed DASD data sets: You cannot
  specify a volume count for an existing system-managed DASD
  data set. (If you do, the system will ignore it.) When you
  create a new system-managed DASD data set, the volume count
  defined in the data class may be overridden by using the
  volume-count subparameter. However, if the volume-count
  subparameter specifies a value greater then 59, the system
  will set the volume count to a maximum of 59. The maximum
  volume count for a VSAM or System-Managed DASD data set is 59.
  Volume Count for Tape Data Sets: The volume count is the
  upper limit on how many volumes the data set can reside on.
  The maximum value is 255. If you do not specify a volume
  count on the volume-count subparameter on the DD statement
  and the data set has a data class, the system can use the
  volume count in that data class.
  
  When your job begins to extend the data set to another
  volume, the system extracts the volume count from the data
  class as the data class is currently defined. If your data
  set does not have a data class or the data class has no
  volume count, then the system uses a maximum count of 255.
  The system can extend your data set to more volumes than
  the volume count but never more than 255. If the volume
  count is 1 through 5, the system allows 5 volumes. If the
  volume count is greater than 5, the system allows 5 plus
  a multiple of 15 volumes.
  
  Volume count for system-managed tape data sets: If you
  specify a volume count and DISP=PASS on a DD statement, the
  system will pass the volume count to subsequent receiving
  steps within the job. This may cause the system to allocate
  more devices than expected to the receiving DD. Coding
  UNIT=AFF in the receiving step's DD will result in the
  optimum number of devices being allocated to the receiving
  DD. For more information about the number of devices
  allocated, refer to the z/OS MVS JCL User's Guide.
  
  The following updates will be reflected in a future revision
  of z/OS MVS JCL User's Guide, in Ch. 15 Data Set Resources -
  Allocation, Multivolume data set for non-system-managed data
  sets and Data Sets on a System-Managed Tape Volume:
  
  If your data set does not have a data class or the data class
  has no volume count, then the system uses a maximum count of 
  255. The system can extend your data set to more volumes than
  the volume count but never more than 255. If the volume count is
  1 through 5, the system allows 5 volumes. If the volume count is
  greater than 5, the system allows 5 plus a multiple of 15
  volumes.
  

Temporary fix

Comments

• ×**** PE17/12/12 PTF IN ERROR. SEE APAR OA54541  FOR DESCRIPTION
  

APAR Information

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

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

  UA76740 UA76741 UA79987 OA49623

Modules/Macros

• IFG0194A
  

Fix information

• Fixed component name

  DATA MGMT SUPPO

• Fixed component ID

  5695DF107

Applicable component levels

• R210 PSY UA76741

     UP16/10/28 P F610

• R220 PSY UA79987

     UP16/10/28 P F610

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.