IBM Z9, Planning Manual

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3. 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.
4. 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. Doing this, 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.
5. 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. Doing this 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.
6. Within each LP, configure primary and backup paths from separate channel
adapter cards.
7. Within each LP, configure primary and backup paths from separate self-timed
interfaces (STIs).
Recovery Considerations
When planning for recovery, consider the following I/O configuration guidelines.
v
Assign channel paths to LPs as described in “Guidelines for Setting Up the I/O
Configuration” on page 2-5.
v Review the recoverability characteristics of the I/O configuration described in the
section “Shared Devices” on page 2-31.
2-6
PR/SM Planning Guide