Question: I have a database that has a 28gig transaction log file. Recovery mode is simple. I just took a full backup of the database, and then ran both:

`backup log dbmcms with truncate_only`

DBCC SHRINKFILE ('Wxlog0', TRUNCATEONLY)

The name of the db is db\_mcms and the name of the transaction log file is Wxlog0. 

Neither has helped. I'm not sure what to do next.

Answer: 
Don't you need this

```
DBCC SHRINKFILE ('Wxlog0', 0)

```

Just be sure that you are aware of the dangers: see here: [Do not truncate your ldf files!](http://blogs.lessthandot.com/index.php/DataMgmt/DBAdmin/MSSQLServerAdmin/do-not-truncate-your-ldf-files)

And here [Backup Log with Truncate\_Only: Like a Bear Trap](http://sqlserverpedia.com/blog/sql-server-backup-and-restore/backup-log-with-truncate_only-like-a-bear-trap/)
I know this is a few years old, but wanted to add some info.

I found on very large logs, specifically when the DB was not set to backup transaction logs (logs were very big), the first backup of the logs would not set log\_reuse\_wait\_desc to nothing but leave the status as still backing up. This would block the shrink. Running the backup a second time properly reset the log\_reuse\_wait\_desc to NOTHING, allowing the shrink to process.