I had been using "NET USE j: \\SAMESERVER\C$\SQL\SQL_Data\J /persistent:yes", even to the point of running through a scheduled task in a batch script, as the service account. The service account is not logged onto the machine at any time.
I was hoping the trace flag would work, but appears to not. Good information to note. Maybe playing with the trace flag at levels above session may give me a better start.
I had been running
DBCC TraceON (1807)
ALTER DATABASE [DATABASE] ADD FILE
( NAME = N'TESTING',
FILENAME = N'J:\TESTING_Archive.ndf' ,
SIZE = 3072000KB ,
FILEGROWTH = 10%) TO FILEGROUP [TestAnother]
I had been getting the error of
Msg 5133, Level 16, State 1, Line 2
Directory lookup for the file "J:\LIFT_Data_Archive.ndf" failed with the operating system error 3(The system cannot find the path specified.).
Msg 5009, Level 16, State 8, Line 2
One or more files listed in the statement could not be found or could not be initialized.