This part describes the Time Sharing Option Extensions (TSO/E) OMVS command that you use to invoke the shell and the TSO/E commands that you can use to work with the z/OS UNIX file system.
The OMVS command invokes the z/OS shell. You can enter the OMVS command from TSO/E or from the ISPF command processor panel.
man tsomount
Option 6 is usually preferable, because it does not convert into uppercase the commands that you enter. You should enter a TSO/E command from an ISPF panel that does not convert all the parameters into uppercase; some panels, such as the main ISPF panel, convert what you enter into uppercase. z/OS UNIX System Services is case-sensitive.