| ### manager RPC: A set of remote procedures that implement the operations of an RPC interface and that can be dedicated to a given type of object. See also object, RPC interface. ### manager Entry Point Vector (manager EPV) RPC: The runtime code on the server side uses this EPV to dispatch incoming remote procedure calls. See also Entry Point Vector, manager. ### marshalling RPC: The process by which a stub converts local arguments into network data and packages the network data for transmission. See also network data , unmarshalling. ### mask 1. With respect to DCE ACLs, a set of permissions that may be intersected (logically ANDed) with another set of permissions associated with a specified privilege attribute in order to yield the effective permissions for principals that possess that privilege attribute. 2. To apply a mask. DFS: A pattern of bits or characters used to control the retention or elimination of portions of another pattern of bits or characters, usually through an AND or OR operation. GDS: Refers to the administration screen interface menus. ### mask_obj mask When supported by an ACL manager type, the mask_obj mask represents the greatest set of security: an optional alternate name for a primary name in the registry database. Aliases and the primary name for which they are an alternate share the same UUID and UNIX ID permissions granted to principals other than those that match the user_obj or other_obj. ### master DSA GDS: The DSA that contains the master entry of an object. ### master entry GDS: The original entry of an object. This is the entry in the DSA that is specified in the master knowledge attribute of the entry. ### master information GDS: The information from the master entries. ### master knowledge attribute GDS: An attribute that designates the master DSA of an entry. ### master replica 1. The first instance of a specific directory in the namespace. Once copies of the directory have been made, it is possible to designate a different replica as the master if necessary, but only one master replica of a directory can exist at a time. CDS can create, update, and delete object entries and soft links in a master replica. 2. Security: An instance of a Security Server that accepts queries and updates to its associated registry database. The master replica dynamically propagates its updates to slave replicas. Each cell has only one master replica. See also slave replica. ### maybe semantics RPC: A form of idempotent semantics that indicates that the caller neither requires nor receives any response or fault indication for an operation, even though there is no guarantee that the operation completed. An operation with maybe semantics is implicitly idempotent and lacks output parameters. See also at-most-once semantics , broadcast semantics, idempotent semantics. ### medium convergence A setting that controls the degree to which CDS attempts to keep all replicas of a directory consistent. Medium convergence means CDS makes one attempt to immediately propagate an update to all replicas of the directory in which a change was just made. If the attempt fails, the software lets the next scheduled skulk take care of making the replicas consistent. Skulks occur at least once every 12 hours on a directory with medium convergence. When you create a namespace, the default setting on the root directory is medium. To control convergence, you set a directory's CDS_Convergence attribute. See also high convergence, low convergence. ### megabyte (MB) A unit of measurement for storage capacity equal to 1,048,576 (220) bytes. ### metadata The structural data associated with the file system, such as the organization of directories, inode tables, and links. Metadata is not data supplied by a user; it is information about the structure of user data. ### minimally consistent Said of an object that satisfies various conditions set forth in the definition of its class. ### monitoring window DFS: A separate terminal session dedicated to tracking the activities of a Tape Coordinator on a Tape Coordinator machine. A monitoring window must run on the same machine as the Tape Coordinator and tape drive it is monitoring. ### mount point DFS: An access point to a fileset in the DFS file tree. Once a fileset has been mounted, the resulting mount point looks and acts like a directory in the file tree. ### mount-level directory DFS: The top-level directory of a mounted fileset. It becomes transparently equivalent to the mount point for that fileset after the fileset is mounted. See also mount point. ### multihomed servers DFS Fileset Location Servers or File Servers with more than one IP address listed in the fileset. ### multivalued attribute A collection of attribute instances of the same attribute type attached to a single registry object. ### mutex A synchronization object that provides mutual exclusion among threads. A mutex is often used to ensure that shared variables are always seen by other threads in a consistent state.