We are utilizing Avamar to backup Windows 2008 and 2012 servers in our environment, backing them up with the Windows File System and Windows VSS plugins. We frequently find exceptions on the file system backup for file locks on %windir%\system32\, NTUSER.dat files and other similar objects. It seems like we don't need to worry about backing some of these up with the file system plugin since we are also using the VSS plugin on these same servers. Am I correct in that assumption? If so, how can I determine what to safely exclude from the file system backups? Our dataset is only configured to exclude very few things from that, such as the Recycle Bin.