Do not use TCB any more, replacement component is available : Trust Execution, more powerfull and it can be disable with a single reboot.

To check the TCB state:

# odmget -q attribute="TCB_STATE" PdAt | grep tcb

For information, it's not possible to disable TCB on a server, it prevent from using WPAR. Only way it to reinstall the server from scratch.

As TCB can't never been completely disable, even if you upgrade or migrate a server, you should partially disable it:

odmget -q attribute="TCB_STATE" PdAt | sed 's/tcb_enabled/tcb_disabled/' | odmchange -o PdAt -q attribute="TCB_STATE"

NB: never use this command to enable TCB, you 'll corrupt your LPAR