To perform an offline backup of a database, use operating system commands to copy the database directory. You must shut down the database prior to performing an offline backup.
For example, on Windows systems, the following operating system command backs up a (closed) database that is named sample and that is located in d:\mydatabases by copying it to the directory c:\mybackups\2005-06-01:
xcopy d:\mydatabases\sample c:\mybackups\2005-06-01\sample /s /i
If you are not using Windows, substitute the appropriate operating system command for copying a directory and all contents to a new location.
For large systems, shutting down the database might not be convenient. To back up a database without having to shut it down, you can use an online backup.