After you install a zone, you must log in to the zone to complete its application environment. You might log in to the zone to perform administrative tasks as well. Unless the -C option is used to connect to the zone console, logging in to a zone using zlogin starts a new task. A task cannot span two zones.
Only the zlogin command with the -C option can be used to log in to a zone that is not in the running state.
As described in How to Use Non-Interactive Mode to Access a Zone, you can use the zlogin command in non-interactive mode by supplying a command to run inside a zone. However, the command or any files the command acts upon cannot reside on NFS. The command will fail if any of its open files or any portion of its address space resides on NFS. The address space includes the command executable itself and the command's linked libraries.
The zlogin command can only be used by the global administrator operating in the global zone. See the zlogin(1) man page for more information.