When you rename or move all other files in the database, you should also do the same for the log file. To move or rename the log file, use the Transaction Log utility (dblog). You should run this utility:
After using RESTORE with a new database name
After using RESTORE with the RENAME option
The database server must not be running on that database
when the transaction log filename is changed.
You can also use dblog to rename the transaction log, even if you have not restored the database, given certain restrictions. You can access the Transaction Log utility from the system command line, using the dblog command-line utility. For details, refer to the section Transaction Log utility (dblog) in the Utility Guide.
