IBM Support

OA35057: UNIT CHECK WITH SENSE CODE CMD REJECT,FORMAT0 MSG CODE 3. (LR CCW MISSING IN CHANNEL PROGRAM)

A fix is available

Subscribe

You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • ICYTRACE records (in LOGREC) show Unit check with sense code
    Command Reject, format 0, message3 indicating CCW count less
    than required. This is similar to OA30391, but fix for OA30391
    is applied.
    Along with the ICYTRACE, you will see message
    
    IOS000I dddd,xx,,CMD,A6,0E00,,cccchhhh,volser,jobname,sense-data
    
    The sense data will have '80' at +0 and '03' at byte 7
    (Example: 8000000015FFFF03....)
    This had occurred for a striped data set where the CI size of
    the data set is made up of 2 or more physical blocks.
    In this case, the cluster is defined with a CISIZE of 32768
    and a physical record size of 16384 - meaning it takes 2
    physical records to hold a CI. The channel program that is
    created, results in NOT every track having the same layout
    (some tracks have 3 blocks and some tracks have 2 blocks - and
    this causes the last track of each CA to be short). The Command
    Reject occurs when reading the last track of the CA.
    
    Additional Symptoms:
    
    ICYTRACE Unit check records with a sense code of Invalid Track
    Format.  (Sense=0040....)
    
    DB2 experienced loss of new updated records on dasd and no
    IOS000I messages were seen on the console. The downlevel
    pages for DB2 errors are best diagnosed by performing CHECK
    INDEX, which will flag blocks with incorrect versions. Various
    external symptoms can occur, such as deleted records
    reappearing, updated records not matching the most recently
    logged record, etc.
    
    In all cases, we had a CISIZE of 32K and a BLKSIZE of 16K on a
    data set with multiple extents. THe data set does not have to
    be striped, but does have to have more than one extent. This
    can occur with a CISIZE of 20K, 28K, or 32K.
    (20K and 28K CISIZE are not used by DB2.)
    
    This problem occurs for both z/HPF and non-z/HPF channel
    programs with the CI SIZES stated above.
    

Local fix

  • Change cluster definition so CISIZE is not 20K, 28K, or 32K
    ================================================================
    You may find additional information about CIsizes, physical
    blocking, and CI/CA ratios in the manual "Macro Instructions For
    Data Sets". Look for the appendix titled "VSAM Usage of 3390
    DASD Space".
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: all DFSMS users of linear data sets where    *
    *                 the last track of each control area has      *
    *                 fewer records than the other tracks. This    *
    *                 will be CI sizes of 20480, 28672, and 32768. *
    *                                                              *
    *                 The problem occurs when an application, such *
    *                 as DB2, requests multiple CI's to be updated *
    *                 in a single call to Media Manager.           *
    *                 The structure of this request makes the      *
    *                 exposure appear to be small: there must be   *
    *                 one contiguous set of CI's to be updated in  *
    *                 one dasd extent and a second set of          *
    *                 consecutive CIs in a different extent where  *
    *                 this second extent crosses a CA boundary,    *
    *                 in a single Media Manager request.           *
    *                 The channel program built by Media Manager   *
    *                 for the second extent was improperly formed, *
    *                 as it did not correctly react to the "short  *
    *                 track" at the end of the CA which exist for  *
    *                 the specified CI sizes.                      *
    *                 Applications that use VSAM macros, such as   *
    *                 GET, PUT, ERASE, which includes COBOL, PL/I  *
    *                 CICS, IMS, are not impacted by this error.   *
    *                 Only those applications that directly invoke *
    *                 Media Manager may see this condition         *
    ****************************************************************
    * PROBLEM DESCRIPTION: the channel program does not include    *
    *                      the command necessary to skip from the  *
    *                      last block in one control area to the   *
    *                      first block in the next control area.   *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    

Problem conclusion

  • the short track in the control area is recognized by the fix
    code and the proper command is included.
    

Temporary fix

Comments

APAR Information

  • APAR number

    OA35057

  • Reported component name

    DFSMS MEDIA MAN

  • Reported component ID

    5695DF126

  • Reported release

    B10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2010-12-01

  • Closed date

    2011-02-02

  • Last modified date

    2011-08-08

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

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

    UA58935 UA58936 UA58937

Modules/Macros

  • ICYRBA
    

Fix information

  • Fixed component name

    DFSMS MEDIA MAN

  • Fixed component ID

    5695DF126

Applicable component levels

  • RA10 PSY UA58935

       UP11/02/22 P F102

  • RB10 PSY UA58936

       UP11/02/22 P F102

  • RC10 PSY UA58937

       UP11/02/22 P F102

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.



Document information

More support for: z/OS family

Software version: B10

Operating system(s): z/OS

Reference #: OA35057

Modified date: 08 August 2011


Translate this page: