PI70330: DSNB224I RC00C200F8 ON READ I/O AFTER DASD HARDWARE WAS FIXED. OTHER MEMBER SUCCESSFULLY PROCESSED THE READ I/O.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A READ I/O error DSNB224I RC00C200F8 occurred because of a DASD
  hardware issue.
  But after the hardware issue was resolved, the DB2 member still
  got a READ I/O error DSNB224I RC00C200F8.
  Other members of the data sharing group were successful in their
  READ I/O request.
  A pageset control block did not clear the flag indicating that
  a READ I/O error occurred causing DSNB224I to be issue hours
  after the DASD hardware was fixed.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: DB2 users.                                   *
  ****************************************************************
  * PROBLEM DESCRIPTION: Resource Unavailable RC00C200F8 on an   *
  *                      index root page, persisting long after  *
  *                      the hardware error has been fixed.      *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  After an I/O error has been encountered for a page in a buffer
  pool, DB2 attempts to discard the page from the pool as soon as
  possible in order to drive another read on the next reference.
  If the original hardware error has been fixed, things will
  proceed normally after re-reading the page.  However, for an
  index root page which is "pinned" in the buffer pool, the page
  buffer can never be discarded and the residual "I/O error" flag
  in the PMB control block will cause all subsequent references
  to fail with RC00C200F8.
  

Problem conclusion

• When releasing a page flagged as having had an I/O error, DB2
  will attempt to latch the page and mark it as "read required"
  to force a re-read on the next access, even if the page buffer
  cannot be discarded from the buffer pool.
  

Temporary fix

Comments

APAR Information

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

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

  UI42583 UI42584

Modules/Macros

• DSNB1REL DSNB1RWI
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RA10 PSY UI42583

     UP16/11/29 P F611

• RB10 PSY UI42584

     UP16/11/29 P F611

Fix is available

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