Autologging the VSE Virtual Machine

AUTOLOG is a convenient way to start a large VSE guest running with many I/O devices under z/VM®. The I/O devices needed by the VSE system require considerable contiguous free storage space for the I/O control blocks established by z/VM. If smaller users have logged on to z/VM before you IPL the large VSE guest, there may be insufficient contiguous free storage space available for the required I/O control blocks. As a result, there may be an insufficient number of I/O devices to accommodate the guest VSE system and its application programs.

To ensure sufficient contiguous free storage space for a large production VSE system, log on the VSE machine immediately after z/VM is loaded. To do this, either:

Have the z/VM system operator enter the CP AUTOLOG command before enabling user terminals
Define the AUTOLOG1 virtual machine in the z/VM directory. This is the method we have used in our initialization example. The AUTOLOG1 user ID is the default. You can change the AUTOLOG1 user ID using the STARTUP operand on the SYSTEM_USERIDS statement in the system configuration file.