QUERY MEMASSIST

Read syntax diagramSkip visual syntax diagram Query MEMAssist 1*FOR*USERuserid2
Notes:
  • 1 If QUERY MEMASSIST is executed with the AT command, the userid operand is required.
  • 2 Only class B users may specify this operand.

Authorization

Privilege Class: B, G

Purpose

Use QUERY MEMASSIST to determine the collaborative memory management assist settings for your own virtual machine or another user's virtual machine.

Operands

*
indicates that you wish to display your own virtual machine's MEMASSIST settings.
USER userid
is the user ID of the virtual machine for which you want to display the MEMASSIST settings.

Usage Notes

  1. The initial MEMASSIST settings for your virtual machine are determined as follows:
    1. If the collaborative memory management assist is installed on the system, the initial setting is ON unless the OPTION NOMEMASSIST is specified in the user directory entry.
    2. If the collaborative memory management assist is not installed, the initial setting is OFF.
  2. At z/VM® IPL, the initial MEMASSIST FOR ALL setting is ON, even if the assist is not installed on the machine. This allows a virtual machine to SET MEMASSIST ON, causing the assist to be simulated by z/VM for guest testing purposes.
  3. You can use the class G SET MEMASSIST command to change your MEMASSIST setting. You can use the class B SET MEMASSIST command to change another virtual machine's MEMASSIST setting. For more information, see SET MEMASSIST.
  4. If the collaborative memory management assist is not installed on the machine, guests can still use it by means of the simulation that is built into CP. However, because of the overhead incurred by simulation, this mode of operation is recommended for testing purposes only.

Responses

The response displays the overall setting for all users, followed by the setting and status for the individual user. The response pattern is: 
ALL USERS SET - {ON | OFF}
                          
USER      SETTING   STATUS
userid    setting   status
The possible setting and status combinations are: 
SETTING   STATUS  
OFF       INACTIVE
ON        INACTIVE

ON        INACTIVE,PENDING OFF
(ON)      INACTIVE,PENDING OFF
ON        ACTIVE

ON        ACTIVE,PENDING OFF
(ON)      ACTIVE,PENDING OFF

Any of these may be suffixed by ,SIMULATED.

ALL USERS SET - {ON | OFF}
The setting for ALL USERS is either ON or OFF. The setting is controlled by the class B command SET MEMASSIST ON|OFF FOR ALL, which controls access to the collaborative memory management assist on a system-wide basis.

ON means users can enable the assist for their virtual machines through the SET MEMASSIST ON command and use the assist by executing the EXTRACT AND SET STORAGE ATTRIBUTES (ESSA) instruction.

OFF means users cannot enable the assist for their virtual machines (SET MEMASSIST ON is rejected), and users who are not currently using the assist are not able to begin using it (the ESSA instruction causes an operation exception). However, users who are currently using the assist continue to have access to it until the next virtual machine reset.

USER
The userid field contains the user ID of the virtual machine being queried.
SETTING
This field is ON, (ON), or OFF. This setting is independent of the system-wide setting. That is, the system-wide setting is like one gate to pass through, which can be open or closed. The user setting is like a second gate, which can be open or closed independently of the first gate.

ON means the user has access to the assist and may begin using it if not already doing so.

(ON) means that the user's current setting is ON, but system-wide access to the assist is denied because that setting is OFF. The user may continue using the assist if already doing so.

OFF means the user does not have access to the assist and that execution of the ESSA instruction results in an operation exception.

The default value for this field is determined during logon processing and is set ON if the assist is installed on the machine and OPTION NOMEMASSIST does not appear in the user's directory entry; it is set OFF otherwise.

STATUS
The status field indicates the current disposition of the virtual machine with respect to the assist. The field can be INACTIVE; INACTIVE,PENDING OFF; ACTIVE; or ACTIVE,PENDING OFF. In addition, SIMULATED is appended to the status, if applicable.

INACTIVE means the user is not currently using the assist.

ACTIVE means the user is currently using the assist (that is, the guest has executed at least one ESSA instruction since the last virtual machine reset).

PENDING OFF means the user might be currently using the assist, but that the SET MEMASSIST OFF command has been issued by or for the user. The user might begin or continue using the assist until the next virtual machine reset, at which time the SET MEMASSIST OFF command takes effect.

SIMULATED means the assist is not installed on the machine, and that it is simulated by CP.

Sample responses are:

Response 1: In the following response, the assist is SET ON FOR ALL, SET ON FOR LINUX01, and the software in the LINUX01 virtual machine has begun using the assist. 
ALL USERS SET - ON        
                          
USER      SETTING   STATUS
LINUX01   ON        ACTIVE
Response 2: In the following response, the assist is SET ON FOR ALL and SET ON FOR MANSELL, but the software in the MANSELL virtual machine is not using the assist. 
ALL USERS SET - ON

USER      SETTING   STATUS
MANSELL   ON        INACTIVE
Response 3: In the following response, the assist is SET OFF FOR ALL, superseding the current setting of ON FOR MANSELL. The virtual machine is not now using the assist, and is not permitted to start using it (the assist appears not available to the virtual machine). 
ALL USERS SET - OFF

USER      SETTING   STATUS
MANSELL   (ON)      INACTIVE, PENDING OFF
Response 4: In the following response, the assist is SET OFF FOR ALL, which would normally supersede the individual user setting, ON FOR MANSELL. Because the virtual machine had already begun using the assist before it was SET OFF FOR ALL, it is permitted to continue using it until the next virtual machine reset. At that point, the assist will become INACTIVE, and will appear not available to the virtual machine. 
ALL USERS SET - OFF

USER      SETTING   STATUS
B         (ON)      ACTIVE, PENDING OFF

Messages

  • HCP003E Invalid option - option
  • HCP020E Userid missing or invalid
  • HCP045E userid not logged on