I tried the script below, but I get the error message below.

ALTER DATABASE TestDB

ADD FILEGROUP FG4;

ALTER DATABASE TestDB

ADD FILE

(

NAME = FG4,

FILENAME = 'C:\TestDB\dbfile4.ndf',

SIZE = 2000,

FILEGROWTH = 10%

)

TO FILEGROUP FG4

Msg 5035, Level 16, State 1, Line 1

Filegroup 'FG4' already exists in this database. Specify a different name or remove the conflicting filegroup if it is empty.

Msg 1834, Level 16, State 1, Line 4

The file 'C:\TestDB\dbfile4.ndf' cannot be overwritten. It is being used by database 'TestDB'.