The first time you connect to your GIS server, you will need to add one or more server object containers, or SOC machines, to it. The SOC machines host services and are the work centers of your GIS server. For your GIS server to utilize these SOC machines, you need to link them to the server object manager (SOM).
For a machine to function as a SOC, it needs to have the Server Object Container component of ArcGIS Server installed on it. Additionally, you should have run the GIS Server post install on the container machine, specifying the same SOM Account and SOC Account names and passwords that you used on all of the other machines of your ArcGIS Server system.
To add a server object container machine from ArcGIS Server Manager:
Type the machine name. This is the machine on which you installed the Server Object Container component of the software. For smaller system configurations, this may also be the machine on which you installed the Server Object Manager.
Note: You must type the exact name of the machine; do not use "localhost".