Hi Sreekanth,
Check the users, how many years data is required in cube. I believe it is now 4 years data, based on users response. Let's move 2 years old data to another cube (call it as history), then for further year data and partition use Quarter instead of month. So that your partitions are reduced.
If you multiprovider and there is no restriction on InfoProvider in your queries, then it would have been easy task to create another cube either for new year data OR history data.
conclusion, instead of month use quarter to re partition the cube. Hope it helps!
Thanks,
Umashankar