| ## The dceshared Subtree The files in the dceshared subtree can be kept on local machines or, preferably, they can be exported to other machines in the DCE cell by using DFS. Therefore, shareable files, including binaries that are addressed by @sys, are stored under dceshared. The dceshared subtree is read-only. All files generated by a DCE build, all files delivered to binary licensees, and if appropriate, all files delivered to source licensees are initially stored in the dceshared subdirectories. All files in the dceshared subdirectories are kept unmodified over the lifetime of an installed DCE release. Configuration and data files are only stored as templates in dceshared. The actual working set of data files is located in the dcelocal/var and dcelocal/etc subdirectories. The default pathname prefix for dceshared is /opt/dce, which is a symbolic link to /opt/dce1.0, or for DFS, to /:/opt/dce1.0 (the short form of /.:/fs/opt/dce1.0). This entry is always physically located at the local machine. Therefore, the local system administrator (or the respective software administrator) must have write permission to modify this link. You can redirect this link from the fileset on the local machine to the cell-wide accessible fileset as soon as the local machine is configured and the cell is available; for example, redirect /opt/dce to /:/opt/dce1.0. Note: Special care must be taken because this link is crucial for protecting the local machine if it is running as client and for protecting the server machine if it is acting as service provider. This symbolic link must be created in a protected directory, which is comparable to /etc. Only the local system administrator needs to have write and modify permissions to this directory. To avoid having replicas of dceshared files on local machines, you can use a symbolic link to access the cell-wide versions of these files. If DFS users do not want to have replicas of these files physically stored on their local machine, they can remove the dceshared subtree that is installed on the local machine and redirect the default symbolic link to the cell-wide dceshared subtree, if these particular files are available there. The subdirectory that dceshared points to has a version number associated with the path name that provides the capability of running multiple versions of DCE in one cell. This capability is sometimes required in an intermediate phase of upgrading to a new release. An additional advantage is a simplified deinstallation procedure. If necessary, you can create copies or symbolic links from the other locations to /opt/dce/*, such as dcelocal/var, dcelocal/etc, dcelocal/bin, and /usr/bin. These guidelines are based on the assumption that you want to use the DCE capability of cell-wide file sharing. The path name for dceshared is set at compile time and is not associated with any particular version number. ##