There is only one NIM master for each NIM environment. The master is fundamental to all operations in the NIM environment. This machine must be installed and configured before you can perform any NIM operations. The master must be a standalone machine, running AIX AIX 4.2 (or later) with the NIM master fileset installed. The master manages the NIM configuration database and provides the central point of administration for the NIM environment.
If you set up more than one NIM environment, each comprised of a master and one or more clients on a network, these environments are independent of each other. No configuration information is shared between the different masters.
The rsh command is used to remotely execute commands on clients. To use the rsh command, the $HOME/ .rhosts file (where $HOME is typically "/" for root) on the client is configured automatically by NIM when the client is initialized so that the master has the permissions required to run commands on the client as root. Once a NIM client is running, a user with root authority on a client can disable the master's permissions to push commands onto the client. A user with root authority on a client can also enable the master's push permissions for the client. For more information about the rsh command and the .rhosts file, see AIX 5L Version 5.1 Commands Reference and AIX 5L Version 5.1 Files Reference. For information on how a client can control the master's push permissions, see Controlling the Master or Client.
Consider the following factors when choosing a machine that will serve as the NIM master: