z/OS UNIX considerations

The following restrictions must be considered when running with POSIX(OFF) or POSIX(ON):

• In Language Environment a process can have only one enclave that is running with POSIX(ON), and that enclave must be the first enclave if that process contains multiple enclaves. All nested enclaves must be enclaves with POSIX(OFF).
• C exec() can only be issued from a single-thread enclave.