The DO command executes the accompanying DCL command or DCL
    command procedure on all nodes in the current environment. Each
    DO command executes as an independent process, so no process
    context is retained between DO commands. For this reason, you
    must express all DCL commands in a single command string, and you
    cannot run a program that expects input.

    In an OpenVMS Cluster environment, SYSMAN executes the commands
    sequentially on all nodes in the cluster. Each command executes
    completely before SYSMAN sends it to the next node in the
    environment. Any node that is unable to execute the command
    returns an error message. SYSMAN displays an error message if
    the timeout period expires before the node responds.

    The system cannot display output returned from a command of more
    than 2048 characters without concatenation.

    Three exceptions to be aware of when using the DO command in
    clusters are the following ones:

    o  In a multi-architecture heterogeneous cluster running OpenVMS
       VAX, Alpha, and Integrity servers, some uses of the DO
       command may require special handling. For example, if you
       are installing images that are named differently in each
       architecture, you can still use the DO command if you create
       logical name tables for VAX, Alpha, and Integrity server
       nodes. See the example sequence that follows this description
       for an example.

    o  Some DCL commands, such as MOUNT/CLUSTER or SET
       QUORUM/CLUSTER, operate clusterwide by design. It is best
       to avoid using these kinds of commands with the DO command
       in SYSMAN when the environment is set to cluster. As
       alternatives, you could leave SYSMAN temporarily with the
       SPAWN command and execute these commands in DCL, or you could
       define the environment to be a single node within the cluster.
       Similarly, operations on clusterwide logical names and tables
       operate clusterwide by design.

    o  Make sure that if you redefine the logical DCLTABLES, you do
       so in SYLOGICALS.COM, not in SYSTARTUP_VMS.COM or elsewhere.
       Otherwise, you will receive a command interpreter failure when
       executing a DO command on a remote node.