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: 
This answer has been lifted from [here](http://social.msdn.microsoft.com/Forums/en-US/sqlreplication/thread/34ab68ad-706d-43c4-8def-38c09e3bfc3b/) and is posted here in case the other thread gets deleted:

> 
> The fact that you have non-distributed LSN in the log is the problem.
>  I have seen this once before not sure why we dont unmark the
>  transaction as replicated. We will investigate this internally. You
>  can execute the following command to unmark the transaction as
>  replicated
> 
> 
> 

```
EXEC sp_repldone @xactid = NULL, @xact_segno = NULL, @numtrans = 0, @time = 0, @reset = 1

```

> 
> At this point you should be able to truncate the log.
> 
> 
>
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.