Setting attributes

Red Hat Enterprise Linux 8.6 LPAR mode z/VM guest KVM guest

Directly write to attributes or, for CCW devices, use the chccwdev command to set attribute values.

About this task

Because the KVM hypervisor hides many aspects of physical devices that back virtio devices, the scope for setting device attributes for these devices on KVM guests is limited.

Procedure

  • You can set a writable attribute by writing the designated value to the corresponding attribute file.
  • For CCW devices, you can also use the chzdev or the chccwdev command to set attributes.
    With a single chzdev or chccwdev command you can:
    • Set an attribute for multiple devices
    • Set multiple attributes for a device, including setting the device online
    • Set multiple attributes for multiple devices