Diablo: ULLtraDIMM - CLI Managing Device Groups

Managing Device Groups

Device groups are used to ensure that devices are attached to specific CPUs.

For information about listing device groups and viewing the status of device groups, see: CLI Display Device Information.

This section describes the commands that are used to manage device groups:

• add
• update
• delete

The device group name is a unique identifier for the group. You can use the characters a through z, the numbers 0 through 9, as well as special characters for the group name. There is a character limit of 16; additional characters will be truncated.

Add device group

The add parameter of the device-group command is used to create a device group. You can set the CPU affiliation as required.

[root@mcs ~]# td-cli device-group --add td-cpu-01 01

To verify that the group has been created, use the status parameter of the device-group command:

[root@mcs ~]# td-cli device-group td-cpu-01 --status
Device Group Name:    td-cpu-01
CPU:                  1
Devices:              None

Update device group

The update parameter of the device-group command is used to assign a different name and/or CPU affinity to a device group.

[root@mcs ~]# td-cli device-group td-cpu-01 --update --name td-cpu-02 --cpu 02
 
Group Setting  Current Group Configuration  New Group Configuration
=============  ===========================  =======================
Name:                         td-cpu-01                   td-cpu-02 
CPU:                                     1                        2

Delete device group

The delete parameter of the device-group command is used to delete a device group.

This command requires that there are no devices attached to the group.

[root@mcs ~]# td-cli device-group td-cpu-02 --delete

If you try to delete a group that has devices attached to it, the system generates an error message: Device group <device-group_name> still has devices attached to it. Only empty groups can be deleted. To verify that the device group has been deleted, use the list' parameter of the device-group command:

[root@mcs ~]# td-cli device-group --list
Device Groups:
td-cpu-23
td-cpu-22
td-cpu-21
td-cpu-20
td-cpu-31
td-cpu-29
td-cpu-30
td-cpu-28

The successfully deleted device group will not be in the list.