DASD management is critical to effective data center operation. In a VM environment, users are allocated DASD in the form of virtual disks or minidisks. Minidisks vary in size and usage and can be distributed among many real DASD volumes. These allocations are defined as MDISK statements in the CP source directory. In addition, there are CP-reserved areas on the DASD volumes that are defined outside the CP directory.
The VM DASD utilities identify, analyze, and report on the utilization of your VM system resources and allow you to identify and regain control over incongruent DASD allocations. The utilities provide comprehensive reports that indicate potential minidisk problems and provide you with recommendations to improve DASD allocation. These reports give you complete, relevant and accurate statistical data on CP-allocated DASD. The reports allow you to correct problems before they become issues and reduce the time and money you must spend managing your DASD system.
The VM DASD utilities let you do the following:
- Reclaim unused DASD
- Accurately determine minidisk allocation, distribution, and use
- Assess the costs incurred by in-use, underused, and unused minidisks
- Monitor the use of component resources
- Set thresholds to provide advanced warning of component- and user-minidisk use levels before they become dangerously high
- Increase end user awareness of DASD utilization and costs
- Postpone the need to purchase additional DASD
DASD Utilities Summary:
VMRMDS (Minidisk Scanning)
Gathers empirical data used by the VMRMUA, VMRSDA, and VMRMCA utilities.
VMRMUA (Minidisk Utilization Analysis)
Provides statistical snapshots of CMS minidisk utilization. Produces reports describing different aspects of your DASD system.
Makes recommendations based on those reports.
VMRSDA (System DASD Analysis)
Maps your VM DASD system, including all CP-reserved areas, and identifies potential problems. Validates your DASD (for example, checks for sufficient expansion area for your CP nucleus and alerts you to any overlaps).
VMRMCA (Minidisk Cost Analysis)
Reports on costs incurred by CMS minidisks.
VMRCMQ (Component Minidisk Query)
Reports on component minidisk utilization. Reports indicate when a component minidisk exceeds its threshold value.
We recommend that you run all of the utilities from the VMANAGER user ID. VMANAGER has the appropriate authorizations, privilege classes, and virtual storage to run the utilities. If you use a user ID other than VMANAGER to run the utilities, the user ID must have CP privilege classes B and E. You must link and access the VMANAGER 193 and 195 minidisks. The access mode Z and virtual address 1F1 are reserved for use by the utilities.
Additional requirements are provided on a utility-by-utility basis in the CA Mainframe VM Product DASD Utilities Guide.