All
                               connectors                      Structure      Structure
                               respond to                    state change     available
                               structure                         event          event
    Start                      temporarily                     presented      presented
System-Managed                 unavailable                      to all         to all
   Rebuild                        event                        connectors     connectors
      |                       (synch point)
      |                             |                              |              |
--------------------------------------------------------------------------------------------------
      | - Event exits driven        | - System quiesces all        |              | - System resumes processing
      |   with structure            |   structure requests         |              |   structure requests
      |   temporarily               |                              |              |
      |   unavailable event         | - New structure allocated    |              | - Connectors resume normal
      |                             |                              |              |   structure operations, if
      | - Connectors optionally     | - All connectors connected   |              |   applicable
      |   quiesce structure         |   to new structure           |              |
      |   activity                  |                              |              | - Alter begin event
      |                             | - Data copied to new         |              |   presented to all
      | - All connectors respond    |   structure                  |              |   connectors (if structure
      |   to structure              |                              |              |   size or ratio change)
      |   temporarily               |                              |              |
      |   unavailable event         |                              |              | - Alter end event
      |                             |                              |              |   presented to all
      |                             |                              |              |   connectors (if structure
      |                             |                              |              |   size or ratio change)
      |                             |                              |              |
      |                             |                              |              |
      |------------- Stop rebuild requests permitted --------------|              |
      |                             |                              |              |
      |                             |                              |              |
      |-------------------------- Old structure allocated --------------------|   |
      |                             |                              |              |
      |                             |                              |              |
      |                             |   |--------- New structure allocated ------------------------>
      |                             |                              |              |
      |                             |                              |              |
      |--SVC dump dumps old structure --|-------- SVC dump dumps old ---------|-- SVC dump dumps -->
      |                             |             and new structures              new structure
      |                             |                              |              |