Controlling DASDs

To control DASDs, you need to be able to:
  • Find out a DASD's status
  • Locate a specific DASD volume
  • Dedicate a DASD to a z/VM user or to the production system
  • Remove a DASD from a z/VM user or from the production system
  • Mount a disk pack for a z/VM user or for the production system.
To control system volumes, you must be able to:
  • Attach a system volume to the system
  • Detach a system volume from the system
  • Check the usage of system volumes
  • Check the format of a system volume and if necessary format and allocate it
  • Change the volume identifier or label on a DASD volume.
You also need to be able to:
  • Define a DASD as a dump device
  • Inspect the physical condition of a DASD volume
  • Copy one DASD volume to another

Some storage subsystems (such as the IBM® DASD subsystem) provide nonvolatile storage (NVS), a DASD fast write function, and a dual copy function as well as regular caching. If you have a storage subsystem that provides those functions, you need to know how to activate, display the status of, and deactivate them.

Before you start, you should be aware of the effect of sharing z/VM DASD volumes with other operating systems. If you are not familiar with operating z/VM with shared DASD, see Operating with Shared DASD Volumes.

Note: The following information includes a discussion about the cache subsystem, nonvolatile storage (NVS), and DASD fast write. To manipulate data within the IBM DASD subsystem, you must activate the DASDFW, CACHE, and NVS features. To do this, enter the following three commands:
set cache subsys on
set nvs on
set dasdfw on