When a non-SSM host is promoted to take over the functions for an SSM host, the SSM window and cycle, the status of the ARCMMEXT exit, and SSM restart variables from the original SSM host are copied to the promoted host. Messages ARC0151I and ARC0273I notify the user of the window or cycle updates. Message ARC1522I notifies the user of the promotion, and the promoted host performs all secondary space management functions. If promotion occurs during the SSM window, then the promoted host attempts to restart SSM functions as close to where the original SSM host left off as possible.

If there is more than one SSM host, all of them are eligible to have their responsibilities taken over by other hosts; however, SSM hosts are not eligible to be promoted for other SSM hosts. The number of hosts that can be demoted at any one time is limited by the number of hosts that are eligible to be promoted.