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

Obtain the fix for this APAR.

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 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

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