libvirt iSCSI driver sets is_block_dev=False

[iain MacDonnell]

Trying to use iSCSI with libvirt/Xen, attaching volumes to instances was failing. I tracked this down to the libvirt XML looking like:

<disk type="block" device="disk">
  <driver name="file" type="raw" cache="none"/>
  <source dev="/dev/disk/by-path/ip-192.168.8.11:3260-iscsi-iqn.1986-03.com.sun:02:ecd142ab-b1c7-6bcf-8f91-f55b6c766bcc-lun-0"/>
  <target bus="xen" dev="xvdb"/>
  <serial>e8c640c6-641b-4940-88f2-79555cdd5551</serial>
</disk>

The driver name should be "phy", not "file".

More digging lead to the iSCSI volume driver in nova/virt/libvirt/volume.py, which does:

class LibvirtISCSIVolumeDriver(LibvirtBaseVolumeDriver):
    """Driver to attach Network volumes to libvirt."""
    def __init__(self, connection):
        super(LibvirtISCSIVolumeDriver,
              self).__init__(connection, is_block_dev=False)

Surely is_block_dev should be "True" for iSCSI?? Changing this makes the problem go away - now pick_disk_driver_name() in nova/virt/libvirt/utils.py does the right thing and my volume attaches successfully.

Am I missing something here... ?

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/75438

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/75438
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=bb67b0137e8faebc8892c9176775f02f6dbb920b
Submitter: Jenkins
Branch: master

commit bb67b0137e8faebc8892c9176775f02f6dbb920b
Author: Vladik Romanovsky <email address hidden>
Date: Fri Feb 21 10:36:14 2014 -0500

    libvirt: setting a correct driver name for iscsi volumes

    Setting LibvirtISCSIVolumeDriver class to be identified
    as a block device to determine the correct driver name.

    Change-Id: Idfb89d051ccadab1d4c4b05b817b085e094ff992
    Closes-Bug: #1273496