There are several things that might effect the Snapdrive service startup, it also depends on how many luns that snapdrive have to retrieve to its snap in. There are several hot fixes that were suggested for snapdrive to successfully run. Please use the interoperability matrix tool, apart from that the work around I have introduced is to run snapdrive service to start using a local account. This local account needs to have administrative rights .Create same local user account (admin role) on the filer with same password . Uninstall and reinstall the snapdrive service under this local user account afterwards. This might address the issue with the service being hung upon the server startup.