In Figure 1, assume that secondary logical unit LU1A is in session with an application program APPL1, and that LU1A has LOGAPPL=A50ACCTS coded. When the session with APPL1 ends, VTAM® attempts to establish a session between LU1A and A50ACCTS.

Figure 1. Automatic logon reallocation

If A50ACCTS is inactive, the automatic logon session fails. If the A50ACCTS major node is active to VTAM but it has not opened its ACB yet, the automatic logon session fails, but is initiated when A50ACCTS opens its ACB.

If you use the VARY INACT command to deactivate A50ACCTS, you can only regain the automatic logon sessions with LU1A and LU2A by issuing a VARY ACT,LOGON command for A50ACCTS or reactivating A50ACCTs and then reactivating LU1A and LU2A.