For data management by a processor device in a computing storage environment, a threshold for an amount of Non Volatile Storage (NVS) space to be consumed by any particular logically contiguous storage space in the computing storage environment is established based on at least one of 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. 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.