Since TSM has a support bug free of the "Event Based" for deleting documents, we are using that setting in the TSM policy instead of the "Creation Based".
Why, because that way we have only 1 location to change the retention period. And some customers are changing their mind quite often!
That said, even in the Event Based policy there is a grace period, and for most of our customer it's around a few month, just enough to be able to retrieve the documents with the appropriate indexes.
But if for you 365 is the grace period, then apply it to every storage nodes.
If your question was: if Retention period = Grace Period ?
Then I would say, is the customer, or do you agree to pay for the data disk space for again the period of time for documents that are supposed to be deleted??
And then for some countries (like US from what I know), you must keep the documents for their legal life, but not keeping them after their legal life (at least not too long after they are supposed to be deleted.
There were some lawsuit concerning company that destroyed the documents too soon, and also when they haven't destroyed it in time!!
I don't know if my answer makes sense, I hope so!
Cheers,
Alessandro
