You do
not need to manage logical paths to a control unit
if the control unit supports the number of logical paths required
by the I/O configuration. However, if a control unit does
not support
the number of logical paths required by the I/O configuration, you
can manage logical paths as follows:
- Deactivate unneeded logical partitions (LPs).
- Configure offline unneeded channels. For shared channels, configure
offline unneeded channels on an LP basis.
- For a control unit attached to shared channels, limit the number
of LPs that can access the I/O devices attached to the control unit.
To limit LP access to I/O devices, specify a device candidate
list for each I/O device attached to the control unit. The device
candidate list (determined by the PART, PARTITION, or NOTPART keyword
in the IODEVICE statement) indicates the LPs that can access the I/O
device. LPs not in the device candidate list cannot access
the I/O device.
A shared channel does not establish
a logical path from an LP to an attached control unit if all the I/O
devices attached to the control unit deny access to the LP.
- Use the director to block ports or prohibit dynamic connections
or communication between ports.
- Combinations of the preceding.