Input/Output Configuration Data Set (IOCDS)

An IOCDS defines the logical partitions by name, allocates I/O resources to each of them, and specifies the security characteristics of those I/O resources. The following list describes the security-relevant parameters of each type of IOCDS source statement.

Statement Type
Discussion
ID
No security-relevant parameters.
RESOURCE
Assign logical partition names and MIF image IDs so that explicit control is asserted, and maximum checking of following IOCDS source statements is enabled.
CHPID
  • Use PARTITION parameter to specify which logical partition each channel path is allocated to.
  • Don't use the SHARED parameter for Isolated logical partitions without study of the security implications.
  • Don't use the REC parameter without study of the security implications.
  • Specify whether the channel path is REConfigurable, and specify which logical partitions are to have access (using logical partition names in the candidate list).
  • Don’t use the IOCLUSTER keyword for any Isolated logical partitions.
CNTLUNIT
Specification of the PATH parameter must be accorded care so that a secure configuration results.
IODEVICE
Specification of the CUNUMBR parameter must be accorded care so that a secure configuration results.
FUNCTION
Use PART parameter to specify which logical partition each function ID (FID) is allocated to. Do not allow other logical partitions in FID's candidate list for Isolated logical partitions without study of the security implications.