( 2 Votes )

Having checked out an implementation of TSM for Sharepoint, I was surprised to see that backup data was being retained for longer periods than set in the backup plan. I checked the usual places (Server copygroups, expiration processing, etc) but everything seemed in order. I then turned to google and user groups and after many searches I finally stumbled across an answer to the problem. 

This can be caused by two different TSM server settings for the DocAve node.
1.  The node does not have Del Backup set to Yes
2.  The node's txngroupmax is too low Diagnostics:
1. Check the following:
 Query Node F=D for the node in question and ensure the following is set :
      Backup Delete Allowed: Yes

2. Check the actlog for the following
ANR0445W Protocol error on session 1115630 for node nodename (DocAve) - maximum group transaction size exceeded. (SESSION: 1115630) In the case where the node's Backup Delete Allowed is set to No, update the node so that it is set to Yes. In the case where you are getting the delete errors due to maximum group transaction size exceeded, then you need to update the node's txngroupmax.

During a DocAve backup, the data is segmented into 50mb chunks. This is stored individually on TSM as an object. Because DocAve uses the TSM API, the deletion of the old data is done as a single transaction. If the number of objects it is trying to delete is greater than txngroupmax, then the deletion will fail.