1. A method for data management by a processor device in a computing storage environment, comprising: destaging modified data over a certain time period during a quiesce/resume operation of any particular logically contiguous storage space to an amount of Non Volatile Storage (NVS) space upon performing a code load operation by establishing a threshold for the amount of NVS space to be consumed by the any particular logically contiguous storage space in the computing storage environment based on a Redundant Array of Independent Disks (RAID) type, a number of point-in-time copy source data segments in the logically contiguous storage space, and a storage classification, wherein establishing the threshold for the amount of NVS to be consumed based on the number of point-in-time copy source data segments in the logically contiguous storage space further includes considering resources needed to perform a Copy Source To Target (CST) operation required prior to the point-in-time copy source data segments being destaged; and subsequent to establishing the threshold, establishing an additional threshold for the amount of NVS space based on a predefined percentage assigned to the any particular logically contiguous storage space.