Javadoc
This method performs the first step for all files in the committing process.
For UPLOADs, this is uploading the file to the temporary remote location.
For DELETEs, this is moving the file from the original remote location to a temporary remote location.
If this is a transaction that is being resumed, the
ActionStatus will show that this part has
already been done. In this case, we do not repeat it.
This is the expensive part of the committing process, when we are talking about I/O. Hence this is also
the most likely part to be interrupted on weak connections.