The DRC (Disk Resource Control) command provides information on the current state of the disk resource control system.

Syntax

<old family name>

<new family name>

Explanation

DRC

Displays the current state of the disk resource control system. The following are the states that the DRC command can display:

After a cold-start, the default state of the DRC is inactive.

DRC +

Causes the disk resource control system to be started after the next halt/load if it is not already active or initializing. Note that if the disk resource control system is active or initializing at the time of a halt/load, it is automatically restarted after the halt/load. The DRC+ command is not allowed while the disk resource system is in the process of terminating.

DRC −

Causes the disk resource control system to be terminated if it is active. The DRC − also cancels a pending DRC + request. The DRC − command is not allowed while the disk resource control system is in the process of initializing.

DRC LB <old family name> <new family name>

Informs the DRC system that a family was relabeled when it was not visible to the DRC system. The command causes a new FAMILYLIST entry to be created in the USERDATAFILE for the new family name with the same FAMILYINUSE value as the old family name. The FAMILYINUSE value for the old family name is set to zero. The system performs this operation on all usercodes known to the DRC system to have files on the old family name. You must enter the DRC LB command before the family named by the new family name is brought online on the system that is running the DRC system.

DRC PG <old family name>

Informs the DRC system that a family was purged or destroyed when it was not visible to the DRC system. The command causes the FAMILYINUSE value to be set to zero for all usercodes known to the DRC system to have files on the old family name.

Examples

Example 1

This example displays the current state of the disk resource control system:

DRC

     THE DRC SYSTEM IS INACTIVE

Example 2

This example directs the MCP to start the disk resource control system after the next halt/load:

DRC +

     THE DRC SYSTEM WILL BE STARTED AFTER THE NEXT HALT/LOAD

Example 3

This example directs the MCP to terminate the disk resource control system after the next halt/load:

DRC -

     THE DRC SYSTEM IS TERMINATING

Example 4

This example informs the MCP that a family named ABC was changed to XYZ when the family was not visible to the MCP. Respond with OK to receive confirmation as follows:

DRC LB OLDNAME = ABC NAME = XYZ

    <mix number> DRC LB OLDNAME = ABC NAME = XYZ OK TO CONTINUE

<mix number> OK

    <mix number> DRC LB OLDNAME = ABC NAME=XYZ DONE

Example 5

This example informs the MCP that a family named ABC was purged when the family was not visible to the MCP. Respond with OK to receive confirmation as follows?

DRC PG OLDNAME = ABC

     <mix number> DRC PG OLDNAME = ABC OK TO CONTINUE

<mix number> OK

     <mix number> DRC PG OLDNAME = ABC DONE

Considerations for Use

A family is not visible to the DRC system under the following circumstances:

When a family is visible to the DRC system, changes to disk space usage that occur as the result of the system commands LB (Relabel Pack), PG (Purge), and RC (Reconfigure Disk) are automatically propagated to the USERDATAFILE entries of usercodes that have files on the affected families. Consequently, the system does not execute DRC LB and DRC PG requests if the families named by either the old family name or the new family name are online at the time that you enter the request.

Because these commands can cause substantial changes to information stored in the USERDATAFILE, the system issues one of the following RSVP messages before it executes a DRC LB or DRC PG command:

DRC LB OLDNAME = <family name> NAME = <family name>
   OK TO CONTINUE
    
DRC PG OLDNAME = <family name> OK TO CONTINUE

If you enter the DS (Discontinue) system command, the system does not perform the operation. If you enter the OK (Reactivate) system command, the system continues the operation.