I have encountered a serious problem on my WDS server. I would like to have the mixed mode because I'm deploying Linux with the old method. It works well. And Windows 2003 & 2008 with the new technology WDS.
But the service "Single Instance Storage Groveler" was unable to start. I have searched a long time, I have seen a lot of posts, and finally I decided to debug with the fantastic tools from Mark Russinovich (Process Monitor). I have seen with the help of this program, that the service try to load a file "sis.dat" in the "Volume System Information". I decided to delete the file, and try to restart the service. It creates a new file and started without issue.