The IORM utility routine enhances the I/O properties of BS2000 in native and VM2000 modes.
The following functions are implemented in IORM (and the IORM subsystem) for autonomous, dynamic control of the I/O resources channel, controller, path and device:
IOPT: I/O Priority Handling for Tasks
DDAL: Optimized Dynamic Device Allocation when using ETERNUS CS
IOLVM (SUs /390):
I/O Limit for Virtual Machines (individual VM2000 guest systems)
IORM also offers the following function:
- DPAV (/390-Server) Settings for PAV and FastDPAV:
The existing alias devices and their capacity utilisation can be queried, and for FastDPAV, the alias device count for individual disks can be restricted (Dynamic Parallel Access Volume).
During ongoing operation, IORM collects data on the utilization of the I/O resources and controls I/O operation in accordance with specified threshold values.
The IORM functions IOPT and IOLVM control disk devices.
The IORM function DDAL controls tape devices.
When IORM is used in the monitor system and in the BS2000 guest systems involved in VM2000 mode, the IORM subsystems exchange I/O data and control information via an internal interface.
IORM can be used in native mode and under VM2000. IORM does not work across more than one Server Unit, however.
A detailed description of IORM is provided in the “Utility Routines” manual [15].