I have an instance where LDF files for what ever reason hadn't been added to the maintenance plan to be backed up. The LDF file has now grown to over 500GB and I only have a 650GB hard drive. If I set the recovery model to Simple and Shrink the LOG file will I loose any data? I know it will shrink the size but what about any loss of data, that is what I am worried about? There is enough space to do a FULL database backup first.
The LDF file is the transaction log. If you set the database to simple recovery mode, and shrink the file, you will not lose any business data. You will, however, lose the ability to perform restores of data to a point in time after the last FULL backup. If you have space for it, you can back up the transaction log, then shrink the file. This will lose no business data or recovery data at all.