Comment 5 for bug 1320090

I'm unable to reproduce this. Setting default_ephemeral_format=ext4 in nova.conf, booting and deleting an instance. Node's driver_info fields get updated and cleaned appropriately:

driver_info post-boot:

{u'pxe_image_source': u'9f6345c6-e482-4805-839c-62d6b643e0b5',
u'pxe_ramdisk': u'fdb2c3a9-74f1-48b0-9a05-e678a00ad6c0', u'pxe_root_gb':
u'8', u'ssh_port': u'22', u'ssh_username': u'ubuntu', u'pxe_swap_mb':
u'0', u'pxe_ephemeral_format': u'ext4', u'pxe_deploy_kernel': u'003fa109
-dd9a-4c0a-b51d-64d87573f198', u'pxe_kernel': u'77393603-da4c-4bcc-
9c77-3217df20ddf1', u'pxe_deploy_key':
u'727BL418BCB4C7LDLNRFCYIRR020H9WJ', u'pxe_deploy_ramdisk': u'a6579774
-b88a-4f66-9703-13d9b8063ec1', u'ssh_key_filename':
u'/opt/stack/data/ironic/ssh_keys/ironic_key', u'ssh_address':
u'10.0.0.179', u'ssh_virt_type': u'virsh', u'pxe_ephemeral_gb': u'1'}

driver_info post-delete:

{u'ssh_port': u'22', u'ssh_username': u'ubuntu', u'ssh_virt_type':
u'virsh', u'ssh_address': u'10.0.0.179', u'ssh_key_filename':
u'/opt/stack/data/ironic/ssh_keys/ironic_key'}