root root dir The server will chroot() (i.e. Change its root directory) to this directory on startup. This is not strictly necessary for secure operation. Even without it the server will deny access to files not in one of the service entries. It may also check for, and deny access to, soft links to other parts of the filesystem, or attempts to use ".." in file names to access other directories (depending on the setting of the parameter). Adding a root directory entry other than "/" adds an extra level of security, but at a price. It absolutely ensures that no access is given to files not in the sub-tree specified in the root directory option, including some files needed for complete operation of the server. To maintain full operability of the server you will need to mirror some system files into the root directory tree. In particular you will need to mirror /etc/passwd (or a subset of it), and any binaries or configuration files needed for printing (if required). The set of files that must be mirrored is operating system dependent. / /homes/smb