n is either 1 (true) or 0 (false). The default value is 1.
When ZSTU is enabled (n = 1), InterSystems IRIS® data platform runs the user-defined startup from the ^ZSTU routine.
Changing This Parameter
On the Startup page of the Management Portal (System Administration > Configuration > Additional Settings > Startup), in the ZSTU row, select Edit. Select ZSTU to enable this setting.
Instead of using the Management Portal, you can change ZSTU in the Config.Startup class (as described in the class reference) or by editing the CPF in a text editor (as described in the Editing the Active CPF section of the “Introduction to the Configuration Parameter File” chapter in this book).