Shared DASD can affect the volume characteristics, device status, volume mounting, and unloading at your installation. You can define shared DASD in VATLSTxx as permanently resident on the system; volumes on the DASD can be shared but the DASD itself cannot be physically mounted on another system.
You can also define the DASD as removable; the DASD can be mounted on another system, but first any other system using the device must take the DASD offline. Finally, you can define DASD as reserved; operators can also reserve removable DASD by using the MOUNT command. This means that the DASD is reserved for use by the system and that the device is offline to other sharing systems.
You can control the mount characteristics for shared DASD in a system by using VATLSTxx. Use VATLSTxx to set initial values for the mount characteristics of shared DASD at your installation.
Your operators can use MOUNT, VARY, and CONFIG commands to reserve volumes for the system, take devices offline, and inform other sharing systems about the mounting of the volumes.
For information about VATLSTxx, see z/OS MVS Initialization and Tuning Reference. For information and examples on using MOUNT, VARY, and CONFIG see z/OS MVS System Commands.