Duplicate device number conflicts

IOCP allows duplicate device numbers in an IOCDS only if the duplicate device numbers do not occur in the same logical partition. Therefore, IOCP allows systems to use different logical partitions to integrate a processor complex without changing device numbers.

IOCP requires a unique device number for each device within a logical partition. When IOCP completes without error, the initial configuration contains no duplicate device number conflicts within a logical partition.

Conflicts can occur when the I/O configuration is modified. If a channel path is configured to a logical partition and devices attached to the channel path have device numbers that are already assigned in the receiving logical partition to other online channel paths, a conflict results.

When an I/O configuration is dynamically modified so the logical partition can gain access to a device not previously accessible, a device conflict can occur. The conflicts are detected when commands are processed that change the I/O configuration or when you attempt to activate the logical partition which has the device number conflict. A message displays identifying the error.

The identified device cannot be accessed while a conflict exists. Two types of conflict are possible:

• Conflicts between device numbers for the same device (a shared device)
• Conflicts between device numbers for different devices (unshared devices)

Activation fails if a duplicate device number conflict exists.