MULTISTORE TABLES : Moving Partitions

We are looking for any best practice document to move the data from memory to extended storage or vice versa.

Scenario 1:

When we are trying to move a partition(around 300 million records) from memory to extended storage -- it tooks us 2 hrs to move the data. are there any settings to be changed make the move faster?

Scenario 2:

We have 1.5 billion records in partition 'OTHERS', when we are trying to create a new partition for the table (to move the records from partition 'OTHERS' to the new partition), the job ran for 11 hrs and failed. We observed creation of new partition was running on a single thread.

Is there a way to create new partition using parallel threads? do we need to do any config changes?

Thanks

Srini