IC71159: INFORMIX SERVER ARCHIVE API DOESN'T CHECK IF THE LOGICAL LOG PAGES BEING ARCHIVED DURING L0 BACKUP ARE THE CORRECT ONES

APAR status

• Closed as program error.

Error description

• As a part of a level 0 archive done by Informix Server the
  current logical log is backed up. In case its pages on disk
  contain a stale data only (from previous logical log cycles) the
  Informix Server's Archive API doesn't notice that and sends the
  pages to the backup client (ontape/onbar) without any error.
  This later leads to the problem described as APAR IC70909.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Users performing archive                                     *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * A logical log file backup copies logical log data from the   *
  * server disk storage to external backup media.  In doing so   *
  * it traverses the pages of the logical log file but currently *
  * does not verify its health.  The user has requested the      *
  * addition of checks to detect logical log file corruption.    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to 11.50.xC8 and above for this enhancement.  Should *
  * the warning messages indicating logical log file corruption  *
  * appear during backup of logical logs, the affected logs in   *
  * the server cannot be used for fast recovery and the logs in  *
  * backup cannot be used for restore.  For this reason, issue   *
  * several "onmode -l" commands to advance past the corrupted   *
  * log storage, use "onmode -c" to issue a checkpoint and take  *
  * a level 0 archive.  Please realize that if logical log file  *
  * corruption is detected during backup, whatever led to the    *
  * log file corruption is likely to have corrupted other areas  *
  * of disk storage as well.  Use oncheck to assess the scope of *
  * the likely corruption and repair as necessary.               *
  ****************************************************************
  

Problem conclusion

• Additional checks have been implemented and will be available in
  11.50xC8 and 11.70xC2. If the checks detect logical log file
  corruption, they will print a message in the message log.  In
  11.70xC2, but not 11.50xC8,  they will also raise an alarm.
  
  Note that this is an enhancement, not a defect fix.  Prior to
  these changes, the logical log file backup functionality was
  working correctly.
  

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:

Fix information

• Fixed component name

  IBM IDS ENTRP E

• Fixed component ID

  5724L2304

Applicable component levels

• RB15 PSN

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