Guidelines for setting up the I/O configuration

Follow these guidelines when setting up an I/O configuration.

1. Determine the number of LPs and in which logical channel subsystem (CSS) they exist.
2. Determine if you want to move any channel paths among LPs. If you do, then these channel paths must be defined as reconfigurable in the IOCP CHPID statement. You cannot move a channel path from an LP in one CSS to an LP in another CSS.
3. Determine if you want to share any channel paths among LPs in the same CSS. If you do, then specify these channel paths as SHARED in the IOCP CHPID statement. This specification helps reduce the number of channel paths configured to a physical control unit and device. Make sure that the channel path type supports being shared.
4. Determine if you want to share any channel paths among LPs in different CSSs. If you do, then define these channel paths as spanned by specifying multiple CSS IDs in the PATH keyword of the IOCP CHPID statement. This specification further helps reduce the number of channel paths configured to a physical control unit and device. Make sure that the channel path type supports being spanned.
5. Within each LP, configure primary and backup paths from separate channel adapter cards.
6. Within each LP, configure primary and backup paths from separate self-timed interfaces (STIs).