One of the most common problems DBA’s have is the Transaction Log size. For some reason your transaction log grows, and ends up using all of your disk free space.
Of course you can limit the growth of the transaction log file, but, then you’ll end up with the users complaining about lack of free space in T-Log.
There are, no doubt about it, many ways to check the file size, and the amount of used space, for me, the easiest one is using:
DBCC sqlperf(logspace)
It will return a list with the Database name, Log Size, Log Space used and Status.
For more info, check http://technet.microsoft.com/en-us/library/ms189768%28v=sql.100%29.aspx.