IAmATeaf
Known around here
I typically leave a few 100Gb free, as said above BI can temp go over the allocated amount if it's writing to a current clip file and the maint to remove older clips to bring the space back down hasn't yet run. Not too sure on this but Windows when managing the disk also doesn't like it if you run the drive full. Make sure that you have the trash can and disk management utilities disabled on that drive else Windows might attempt to defrag it.