How to shrink the Sharepoint Config database log file on a 2008 SBS

To reduce the size of the log file, use the following steps.  A full server backup is recommended first.

1.  Open notepad and Copy and paste the following text into notepad.  Save the file as c:\logshrink.sql 

declare @ConfigDB varchar(255);
declare @ConfigDBLog varchar(255);
declare @ConfigDBCmd varchar(255);
select @ConfigDB =  name from sys.databases where name like ‘SharePoint_Config_%’;
set @ConfigDBCmd = ‘BACKUP database [‘ + RTRIM(@ConfigDB) + ‘] to disk=”C:\windows\temp\before.bkf”’;
execute(@ConfigDBCmd);
set @ConfigDBCmd = ‘use [‘ + RTRIM(@COnfigDB) + ‘]’;
execute(@ConfigDBCmd);
set @ConfigDBCmd = ‘BACKUP LOG [‘ + RTRIM(@ConfigDB) + ‘] WITH TRUNCATE_ONLY’;
execute(@ConfigDBCmd);
set @ConfigDBCmd = ‘use [‘ + RTRIM(@COnfigDB) + ‘]’;
execute(@ConfigDBCmd);
select @ConfigDBLog =  name from sys.database_files where name like ‘SharePoint_Config%_log’;
set @ConfigDBCmd = ‘use [‘ +  RTRIM(@ConfigDB) + ‘] DBCC SHRINKFILE([‘ + RTRIM(@ConfigDB) + ‘_log],1)’;
execute(@ConfigDBCmd);
set @ConfigDBCmd = ‘BACKUP database [‘ + RTRIM(@ConfigDB) + ‘] to disk=”C:\windows\temp\after.bkf”’;
execute(@ConfigDBCmd);
go

2.  Open an elevated command prompt and run the following command:
sqlcmd -S \\.\pipe\mssql$microsoft##ssee\sql\query -E -i c:\logshrink.sql
This script will create two backup files (before.bkf and after.bkf) in C:\windows\temp.

Taken from Microsoft's knowledge base article: http://support.microsoft.com/kb/2000544