Reference Guide › Configuration File Reference › DEVTYPE Record › XSTORE Subcommand › Limitations Using CACHE | NOCACHE and MDC | NOMDC

Limitations Using CACHE | NOCACHE and MDC | NOMDC

CA VM:Secure automatically adds MINIOPT records when it updates an object directory. Each time a directory update is made, CA VM:Secure checks each MDISK record in the directory entry against the caching attributes (CACHE|NOCACHE or MDC|NOMDC) on the DEVTYPE record. If no MINIOPT record is present and the specified attributes for the device type are not the CP default, CA VM:Secure adds a MINIOPT record with the caching attributes specified on the DEVTYPE record.

For example, suppose you have a DEVTYPE record similar to this:

DEVTYPE 3390 3390 (NOCACHE NOMDC

The CP default for z/VM systems is CACHE MDC. If you issue the CA VM:Secure EDIT command for a directory entry, CA VM:Secure updates the directory. If there is currently a MINIOPT record following an MDISK record in the directory entry, no changes are made to this MINIOPT record. However, if there is no MINIOPT record following an MDISK that defines a minidisk on a 3390, CA VM:Secure inserts the following MINIOPT record after the MDISK record:

MINIOPT NOCACHE NOMDC

It also updates the object directory and saves the source directory entry on the CA VM:Secure DRCT (1B0) minidisk.

For CA VM:Secure initialization, the scenario may be different. If a SOURCE start is invoked, CA VM:Secure opens each directory entry. If a MINIOPT record is needed for caching, CA VM:Secure sets the correct caching attributes in the object directory. However, the source directory entry is not normally changed and saved on the CA VM:Secure DRCT (1B0) minidisk. The source directory does not contain the MINIOPT record even though the object directory entry is set with the correct caching attributes. You can use the SAVEDIR startup option to change the normal procedure and make CA VM:Secure update all of the source directory entries on the CA VM:Secure DRCT minidisk. For more information about SAVEDIR startup option, see Changing Startup Options in the chapter "Introduction" in the Administration Guide.

A directory update is not invoked during a quick start. Therefore, if the caching attributes on the DEVTYPE record are changed while CA VM:Secure is down and a quick start is invoked at initialization, CA VM:Secure does not make any changes to the online directory to reflect the new caching attributes of the device type. However, subsequent directory updates will recognize the new DEVTYPE record.

The following table lists all device types that CAVM:Secure support: