STN_FREE_SPACE_THRESHOLD > 4GB is truncated
Setting STN_FREE_SPACE_THRESHOLD to a value greater than 2^32-1 (4294967295) will result in the actual value used being truncated to the low-order 32 bits of the number, which will tend to be significantly lower than the intended value.
Workaround
Limit the setting of this configuration parameter to 4 GB / 4294 MB / 4294967 KB or less.
Last updated: 7/10/19