After taking steps to address the size issue of the SBS 2008 monitoring file as described here:
I found that my SBSMonitoring_log.ldf had grown to over 30 GB. The proper size is well less than 1 GB. What we need to do is shrink that LDF file. Here is what I did:
1. Open an elevated SQL Server Management Studio Express
2. Connect to the [servername]\SBSMonitoring database using Windows Authentication
3. Expand Databases and right-click on SBS Monitoring
4. Choose Tasks, then Backup
5. Make a backup of the current database
6. After backing up, right click SBSMonitoring and choose Tasks, Shrink, file.
7. In the opening window, choose Log in the File Type drop down list and click OK.
8. Now the SBSMonitoring_log.ldf file should shrink.
** of note, running the backup in step 4 is recommended, but I didn't run it as I was in a hurry to resolve this problem and it wasn't apparent to me where the backup would go. The C drive would be illogical as I had no space on the C drive. Given my time crunch (the low space on C was causing Exchange problems), shrank the file without backup and it did not cause any problems.