Re: Snapshot space question
Posted: Sat Mar 08, 2014 3:12 am
Returning back after I spoke to a pair of sales engineers about this. Their explanation was that the duplication avoidance only pertains to changed blocks being shared by multiple concurrent snapshots, they did not believe there is any attempt to dedupe or reuse existing blocks in the PIT area that match a newly changed block. I suspect that when Cleanur catches up on this thread he will clarify his position as well.
Building upon your example, this is what is meant by "non duplicative":
Monday evening snapshot = just metadata
Tuesday evening snapshot = just metadata
Wednesday evening snapshot = just metadata
Thursday working day the cell changes, old data copied to PiT area and ALL 3 snapshots updated to point to it and new data written to "live" VV.
Building upon your example, this is what is meant by "non duplicative":
Monday evening snapshot = just metadata
Tuesday evening snapshot = just metadata
Wednesday evening snapshot = just metadata
Thursday working day the cell changes, old data copied to PiT area and ALL 3 snapshots updated to point to it and new data written to "live" VV.