If you have installed Report Center, then the size of your eHealth Oracle Database AND each individual Database Save increase approximately 50%.
When you combine the affects, the amount of space required by an eHealth Database Save can triple from previous versions.
The NH_BACKUP_HISTORY table contains the information on the previous DB save, including size.
Even though one can remove the prior .tdb save from the target directory before running the save, the save still accounts for its size during the space check because it gets the information from the NH_BACKUP_HISTORY table. This is why the save can continue to fail due to a lack of free disk space. This is also why the save run using the -noDiskSpaceCheck option will be successful.
Until more disk space can be added, as a work around first remove the old .tdb save and then run the database save using the -noDiskSpaceCheck argument.