Hi
I got similar upgrade quite recently. In my case I went to second scenario
from your list (finally it took less than 1 hour to reorg index of
BACKUP_OBJECTS of 200GB 4 year old DB previously running 6.2  ).
To prevent server from crashing you can follow document
http://adsm.se/?p=280 Focus on parts about monitoring status messages and
cancelling index reorganization (in case of ending log space or too big
load).
Unfortunately, I did not found any documentation about calculating time of
those reorganizations too.
Good luck.

Krzysztof Przygoda

2015-04-23 17:11 GMT+02:00 Thomas Denier <Thomas.Denier AT jefferson DOT edu>:

> We have a number of TSM server instances running under zSeries Linux.
> These were created with 6.2.2.0 server codes, subsequently upgraded to
> 6.2.5.0, and upgraded to 6.3.5.0 in early April. One of the server
> instances is now displaying the message:
>
> PM ANR3497W Reorganization is required on excluded table BACKUP_OBJECTS.
> The reason code is 2.
>
> every few days. The messages manual and various technotes mention the
> following three options:
>
> 1.Do nothing, and risk ongoing growth in disk space  used by the database
> and ongoing decline in performance.
> 2.Enable online reorgs of BACKUP_OBJECTS, lock out smaller reorgs for
> periods that might stretch into months, and risk crashing the server.
> 3.Take the server down for "many hours" to perform an offline reorg.
>
> The discussion of the advantages and disadvantages of each option is
> maddening vague. All sorts of things "might" happen, but hardly anything
> "will" happen. Timing is discussed only in terms like "many hours". As far
> as I can tell, the writers' main goal was to ensure that IBM will never be
> blamed for giving bad advice, and they achieved this goal by the simple
> expedient of refusing to give any advice.
>
> Is there any documentation available that provides real help in deciding
> which option would be best for our situation?
>
> Thomas Denier
> Thomas Jefferson University
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