MF68776 - LIC Possible data loss after IPL or IASP vary off.

TYPE PROGRAM  RELEASE   NUMBER   MIN/MAX  OPTION
---- -------- --------- -------  -------  ------
TR   5770999  V7R3M0    MF99211   00/00    0000



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-------
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APAR Error Description / Circumvention

-----------------------------------------------
When shutting down the system or varying off an IASP we use
multiple scan tasks to find any changed pages in the system or
IASP, then send messages detailing which pages to write to a
different set of tasks that issue asynchronous IO to write these
pages.  Once the scan tasks complete we must wait for these
asynchronous writes to complete, so each write tasks is queried
to determine the number of outstanding asynchronous writes.  If
there are none we proceed to the next step in shutting down the
system or varying off the IASP.  It is possible that at the
moment we query the write tasks they have no outstanding
asynchronous writes, but do have unprocessed write messages on
their queue.

CORRECTION FOR APAR MA49088 :
-----------------------------
The code is changed to wait until each write task has no
outstanding asynchronous writes and the write message queue is
empty before proceeding to the next step of the shutdown or IASP
vary off.  This will ensure all writes complete in their
intended order.

CIRCUMVENTION FOR APAR MA49088 :
--------------------------------
None.


Activation Instructions


None.




Special Instructions


None.


Default Instructions

THIS IS A DELAYED PTF TO BE APPLIED AT IPL TIME.



Supersedes

PTF/FIX NO(S).  APAR TITLE LINE
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     NONE

Summary Information

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