Multihead
From Sun Ray User Group Wiki
With the Multihead feature, you can have up to 16 Sun Rays controlled by one keyboard and mouse.
Sun Ray 2FS treats both screens as a single piece of glass. Xinerama like functionality is the only way it operates when two monitors are attached. However if you had two Sun Ray 2FS units with four monitors you could create a multihead group to make it two distinct workspaces or 1 large workspace.
Multihead must be enabled via group policy before tools such as utmhadm and utmhconfig can be used. Xinerama is controlled via the utxconfig tool.
Multihead and Xinerama with Sun Rays Blog Entry: http://blogs.sun.com/ThinkThin/entry/multihead_sun_rays
Examples of a 2x1 Multihead groups with Xinerama enabled.

