It seems I had someone trying to perform brute-force login attempts on my SQL 2005 server. As a result, the log file has grown to about 55 gigs and sits in C:\Windows\SYSMSI\SSEE\MSSQL.2005\MSSQL\Data.
The file itself is called WSS_Content_0b8dae5814114114b874e35ea7ba795b_log.LDF and appears to be currently used.
I'm unclear on how to clear or truncate this LDF file. Thanks!
Open SQL Server Management Studio, connect to the SQL server, find the relevant database. Right click the DB, Tasks->Shrink->Files. File type: Log, verify the file name. It will display how much is used/free.
If it's all used, you should backup the database so that it's no longer using the log file. If it's mostly empty you can proceed with releasing the unused space (or whatever portion you'd like).
If you don't want to backup the DB, you can change the recovery model (right click DB, Properties, Options tab, Recovery Model) to something simpler, or off all together if you want.
I'm pretty sure that logins/login attempts don't get logged to the SQL transaction log. The cause is most likely due to the fact that the database is using the Full Recovery model and log management is not occurring.
That is the log file for a Sharepoint content database. It is in use because the associated database is attached and the SQL service is running.
How do you know that the login attempts are directly responsible for the log file being large? How active is your Sharepoint site?
I'm adding this as an answer because I can't vote or comment. The link posted by John does the trick and is a thorough step by step ( http://network-nick.blogspot.co.uk/2011/11/sbs-2008-c-drive-runs-out-of-space.html ), and should be at the top really because in SSEE you can't do it through the GUI (properties doesn't work). A summary is below:
Open SQL Management Studio and connect to:
\.\pipe\mssql$microsoft##ssee\sql\query
Open up a new query and run:
ALTER DATABASE "Database_name" SET RECOVERY SIMPLE
(Be sure to include the quotation marks if the database name has hyphens!)
Once complete you'll need to free up unused space in the log file as mentioned in one of the previous posts - Right click the DB, Tasks->Shrink->Files. File type: Log. (This usually doesn't free up much space until you've done the previous steps of switching your recovery model to simple.)