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VM66104: Z/VSE GUEST FAILS WITH UNIT CHECK/FILE PROTECT ERROR

A fix is available

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APAR status

  • Closed as program error.

Error description

  • z/VSE guest program failing with Unit Check and sense indicating
    File Protect error.  This fails only on 640.  Previous releases
    report Unit Check with End of Cylinder.
    z/VSE message: 0P17I MSG0P17I FILE PROT running LVTOC
    and volume was initialized with DOSVTOC(END)
    

Local fix

  • Disable STP_Timestamping in the VM System Configuration file to
    circumvent the problem.
    .
    VM Note:  The root cause of this problem appears in code as far
    back as 5.4 when STP_Timestamping is enabled in the VM System
    Configuration file.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All z/VM users of STP_Timestamping           *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    ****************************************************************
    * RECOMMENDATION: APPLY PTF                                    *
    ****************************************************************
    When STP_Timestamping is enabled in the system configuration
    file, VM must insert Define Extent data in the channel program,
    if not already present, in order to provide the time stamp.  In
    this error scenario, there is no Define Extent data from VSE
    since VSE issues CKD I/O.  Therefore, VM inserts the Define
    Extent.  This is the root cause of the problem.
    
    During normal CKD I/O processing, VSE expects to get an End of
    Cylinder error when searching for a record and hitting the end
    of the last track on a cylinder (without finding the record).
    However, because z/VM inserted the Define Extent, VSE receives
    the File Protect error instead if searching to the end of the
    last cylinder of the minidisk.  This is because architecturally
    the search has hit the end of the defined extent.  The File
    Protect error is unexpected by VSE and causes the external error
    condition.
    

Problem conclusion

  • CCW translation code was modified to remember when Define Extent
    data is inserted in the channel program due to STP_Timestamping.
    CCW UNtranslation was modified to convert a File Protect Error
    to an End of Cylinder error if the Define Extent was inserted by
    CP (as remembered in CCW translation).  This logic was done for
    both dedicated DASD as well as minidisk CCW translation /
    UNtranslation.  This logic specifically hit Set File Mask, Seek
    (all flavors), and channel program redrive processing in CCW
    translation & UNtranslation (for dedicated DASD and minidisks).
    
    This fix piggybacks on similar logic added many years ago for
    Define Extent data inserted to bypass the controller cache when
    MINIOPT NOCACHE was specified in the user directory.
    

Temporary fix

  • FOR RELEASE VM/ESA CP/ESA R640 :
    PREREQ: VM65943
    CO-REQ: NONE
    IF-REQ: NONE
    

Comments

APAR Information

  • APAR number

    VM66104

  • Reported component name

    VM CP

  • Reported component ID

    568411202

  • Reported release

    640

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-12-08

  • Closed date

    2018-02-14

  • Last modified date

    2018-12-14

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

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

    UM35279

Modules/Macros

  • HCPDDP   HCPDUP   HCPIORBK HCPMDP   HCPMD1   HCPUNT
    

Fix information

  • Fixed component name

    VM CP

  • Fixed component ID

    568411202

Applicable component levels

  • R640 PSY UM35279

       UP18/02/22 P 1802

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/VM family

Software version: 640

Operating system(s): z/VM

Reference #: VM66104

Modified date: 14 December 2018