We are running a SQL 2012 std. instance on a 2008 R2 platform. It is a VM on ESXi 5.5. Drives are on a hybrid SAN with plenty of bandwidth. To further speed things up I am running Dataram ramdisk to create a 30GB ramdisk for tempdb. Moving tempdb to the ramdisk is trivial, but I am wanting to ensure that SQL does not run out of space for tempDB should something go off in the weeds. I think it is fairly straightforward to add another location to tempdb file locations, but is there a way to prioritize them? Of course we want to use all the ramdrive before going to the virtual hard drive. And is there a way to trigger a shrink back to the ramdrive should it exceed?