I have seen this problem and have an apar open with Tivoli.
We can't TEC alert, if there's no specific message that a drive went
offline...
other than perhaps a anr9999d (we're not going to rightly tec alert on
THAT message):
IC34067
    Item IC34067


  APAR Identifier ...... IC34067       Last Changed..02/07/10
  TSM SERVER TAKES TAPE DRIVE OFFLINE (MAKES IT UNAVAILABLE) BUT
  NO MESSAGE IS OUTPUT INDICATING THIS ACTION HAS OCCURED.

  Symptom ...... IN INCORROUT         Status ........... CLOSED  PER
  Severity ................... 2      Date Closed ......... 02/07/10
  Component .......... 5698TSMAX      Duplicate of ........
  Reported Release ......... 420      Fixed Release ............ 999
  Component Name TSM AIX SERVER       Special Notice
  Current Target Date ..              Flags
  SCP ................... AIXRSC
  Platform ............ AIX

  Status Detail: Not Available

  PE PTF List:

  PTF List:
  Release 420   : PTF not available yet
  Release 410   : No PTF planned


  Parent APAR:
  Child APAR list: IC34101 IC34102 IC34103 IC34107


  ERROR DESCRIPTION:
  Customer is attempting to pass all critical messages to the TEC.
  One message of importance to them are those that indicate a tape
  drive had been taken offline (made unavailable). Customer has
  found certain circumstances under which no message appears to
  be issued when a drive is taken offline. For example the
  following shows activity log messages about a drive followed
  by query drive message that show it was taken offline during
  this time even though no message indicating this action was
  issue:
  TSM drive messages:
  06/24/02   14:22:27      ANR8469E Dismount of LTO volume 100309
  from drive EF2D1 (/dev/rmt18) in library LTOPLANO01 failed.

  06/24/02   14:22:27      ANR9999D mmsscsi.c(1723): ThreadId<66>
  may still be  in the drive EF2D1 (/dev/rmt18).
  Library Name: LTOPLANO01

  Query Drive f=d output at 17:00:08:
   Drive Name: EF2D1
   Device Type: LTO
   On-Line: Unavailable Since 06/24/02 14:22:27
   Device: /dev/rmt18
   Element: 269
   Allocated to:
   Last Update (administrator): TWILL1
   Last Update Date/Time: 06/18/02 12:55:56

  The TSM server needs to issue an ANR message each time it takes
  a drive offline.


  LOCAL FIX:


  PROBLEM SUMMARY:
  ****************************************************************
  * USERS AFFECTED: Anyone affected by inconsistent messaging    *
  *                 when drives are taken offline.               *
  ****************************************************************
  * PROBLEM DESCRIPTION: Inconsistent messaging when a drive is  *
  *                      taken offline.                          *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  We display a couple of different messages whenever a drive is
  taken offline.  Moreover, there was a couple of situations
  when no message was displayed at all and the drive was taken
  offline.


  PROBLEM CONCLUSION:
  Therefore, we added a message anywhere that the drive was
  taken offline to prompt the user of such action.


  TEMPORARY FIX:


  COMMENTS:


  MODULES/MACROS:   NONE


  SRLS:      NONE


  RTN CODES:


  CIRCUMVENTION:


  MESSAGE TO SUBMITTER:




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