If you put the database log in a non-default location prior to backing up the database, be aware of the following requirements.
xcopy d:\mydatabases\sample c:\mybackups\2012-04-01\sample /s /i xcopy h:\janet\tourslog\log c:\mybackups\2012-04-01\sample\log /s /i
If you are not using Windows, substitute the appropriate operating system command for copying a directory and all of its contents to a new location.
See Logging on a separate device for information about the default location of the database log and about putting the log in a non-default location.