The BACKUP LOG WITH NO_LOG and WITH TRUNCATE_ONLY options are discontinued in SQL Server 2008.
There is no replacement for this functionality. When the command is executed there is the message suggesting to switch to Simple Recovery.
Of course , a SQL Server DBA knows that this breaks the Log Chain, and a full backup is required to start a new Log Chain.
There are plenty of DBA scripts in Production environments that use BACKUP LOG WITH NO_LOG in SQL Server 2005 . Some thoughts to consider:
1) NO_LOG and TRUNCATE_ONLY are similar
2) Switching from FULL Recovery to SIMPLE Recovery will break the log chain.
3) Using NO_LOG in SQL Server 2005 will create a BACKUP with no logs
4) If used with BACKUP LOG , a checkpoint is forced. The transaction log is truncated.
5) If using NO_LOG , the truncated portion is not recoverable. Good practise is to commit a full BACKUP after the NO_LOG (or TRUNCATE_ONLY)
6) Use the NO_LOG only if absolutely necessary.
7) If Log file growth management is required – use monitoring and regular BACKUPs to manage growth