IBM Support

OA45952: AFTER UNIT CHECK, SUCH AS IFCC, MEDIA MANAGER RECOVERY SKIPS RECORDS DURING READ.

A fix is available

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • In some rare cases when Media Manager retries a failed channel
    program, it may not read or write all of the blocks that were
    requested.  Media Manager may terminate the request early. This
    can occur for MIDAW or zHPF channel programs if redriven.
    
    In the case presented for this apar, under z/OS 1.10, the
    program was reading a SAM extended format data set. There were
    63 CI's passed to MM to read. MM created 3 zHPF channel
    programs. If the read received an IFCC due to a hardware
    defect, MM will re-do the reads in Command Mode using non-zHPF
    channel programs and he skips some of the 63 CI's, with no
    indication back to the application. The number of CI's skipped
    is variable dependent on where the IFCC was presented in the 3
    channel programs.
    Message IOS050I IFCC was seen in the syslog and joblog.
    

Local fix

  • Turn off zHPF and MIDAW functions via the SETIOS  MVS command.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All dfsms users at HDZ1A10                   *
    ****************************************************************
    * PROBLEM DESCRIPTION: after a media manager retryable IO      *
    *                      error, a flag is left on which may      *
    *                      cause the retry of the failed IO to     *
    *                      terminate early.                        *
    *                      this may cause IO to  be incorrectly    *
    *                      reported as complete. Updates writes or *
    *                      reads may have been skipped.            *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    

Problem conclusion

  • when calculating space for a channel program and a CI is added
    to the channel program, the bit zzpllst will be set off. This
    will clear this bit in case it was set on in a prior channel
    program build path.
     KEYWORDS: ZHPF/K
               DATALOSS
    

Temporary fix

  • *********
    * HIPER *
    *********
    

Comments

APAR Information

  • APAR number

    OA45952

  • Reported component name

    DFSMS MEDIA MAN

  • Reported component ID

    5695DF126

  • Reported release

    A10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2014-08-28

  • Closed date

    2014-09-09

  • Last modified date

    2015-02-10

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

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

    UA74783

Modules/Macros

  • ICYBLD64 ICYPIO64
    

Fix information

  • Fixed component name

    DFSMS MEDIA MAN

  • Fixed component ID

    5695DF126

Applicable component levels

  • RA10 PSN UA74783

       UP14/09/10 P F409 Ž

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.

[{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SG19M","label":"APARs - z\/OS environment"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"A10","Edition":"","Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
10 February 2015