Enabling and disabling a device

6.18 LPAR mode z/VM guest KVM guest

You can use the chzdev command to enable or disable a device, both in the active and in the persistent configuration.

About this task

Any steps necessary for the device to function are automatically taken. If a cio_ignore device exclusion list is active, chzdev removes the specified device ID from the list.

Note: If a SCSI device is enabled and its FCP device taken off the cio_ignore exclusion list, all devices defined to the FCP device might come online automatically.

where:

-d or --disable

disables the selected devices.

Active configuration: Disables the selected devices by reverting the configuration steps necessary to enable them.
Persistent configuration: Removes configuration files and settings associated with the selected devices.
You can limit this persistent change to a particular site.

-e or --enable

enables the selected devices. Any steps necessary for the devices to function are taken, for example: create a CCW group device, remove a device from the CIO exclusion list, or set a CCW device online.

Active configuration: Performs all setup steps required for a device to become operational, for example, as a block device or as a network interface.
Persistent configuration: Creates configuration files and settings associated with the selected devices.
You can limit this persistent change to a particular site.

-a or --active

applies changes to the active configuration only. The persistent configuration is not changed unless you also specify --persistent.

Note: Changes to the active configuration are effective immediately. They are lost on reboot, when a device driver is unloaded, or when a device becomes unavailable.

-p or --persistent

applies changes to the persistent configuration only. The persistent configuration takes effect when the system boots, when a device driver is loaded, or when a device becomes available.

-s<site_id> or --site <site_id>

applies changes to the persistent configuration for the scope of a particular site that is identified by <site_id>. The site identifier <site_id> is an integer in the range 0 to 9. For more information about site-specific configurations, see Site-specific Linux instantiation.

Examples

To enable an ECKD™ DASD with bus ID 0.0.3718 in both the active and the persistent configuration, specify the device ID and its type to the chzdev command, together with the --enable option:
```
# chzdev dasd-eckd 0.0.3718 --enable
ECKD DASD 0.0.3718 configured
```
This command sets ECKD DASD 0.0.3718 online and creates udev rules to automatically bring it online at the next boot.
To restrict the scope of the configuration actions to either the active or persistent configuration, specify --active or --persistent. The following command creates udev rules to automatically bring device 0.0.3718 online at the next boot:
```
# chzdev dasd-eckd 0.0.3718 --enable --persistent
Configuring devices in the persistent configuration only
ECKD DASD 0.0.3718 configured
```
To disable a device, specify its device type and ID together with the --disable option:
```
# chzdev dasd-eckd 0.0.3718 --disable
ECKD DASD 0.0.3718 deconfigured
```
To enable an ECKD DASD with bus ID 0.0.f001 in the persistent configuration for a specific site with ID 3, specify the device ID and its type to the chzdev command, together with the --site option:
```
# chzdev dasd-eckd 0.0.f001 --enable --site 3
Configuring devices in the site 3 configuration only
```
This command sets ECKD DASD 0.0.f001 online and creates a persistent configuration that sets in online for the next boot in the site 3 context.

To enable an FCP device and create a persistent configuration, issue:

# chzdev --enable zfcp-lun 0.0.198d:0x50050763070bc5e3:0x4006404600000000

To enable a FCP device without creating a persistent configuration, issue:

# chzdev --enable --active zfcp-lun 0.0.198d:0x50050763070bc5e3:0x4006404600000000

To enable a QETH device and create a persistent configuration, issue:
```
# chzdev --enable qeth 0.0.a000:0.0.a001:0.0.a002
```
To enable a QETH device without creating a persistent configuration, issue:
```
# chzdev --enable --active qeth 0.0.a000:0.0.a001:0.0.a002
```