The SET DEVICE/SERVED command is used in conjunction with the mass 
storage control protocol (MSCP) server to make a disk on a local node 
available to all nodes on the cluster. The local node must be a member 
of an OpenVMS Cluster, and the local MSCP server must have been invoked 
by the System Generation utility (SYSGEN).
You cannot use the SET DEVICE/SERVED command under the following 
conditions:
  - In service of a Phase II shadow set virtual unit
  
 - On devices that are already mounted
  
 - On system disks
  
 - On quorum disks
 
The SET DEVICE/SERVED command string can be included as part of the 
local startup command file and entered before the Mount utility mounts 
the disk to be served (made available to the entire cluster).