[Pkg-libvirt-maintainers] Bug#797850: virsh cant specify disk device block-xxx script

[Andreas Pflug]

Package: libvirt-clients
Version: 1.2.9-9


Non-standard block devices may be used as disk for xen using
/etc/xen/scripts/block-xxx scripts. In my case, I'm using a special lvm
driver block-lvm
With old xm configurations, it was possible to specify
  disk=["lvm:vg/lv,xvda1,w"]
xl won't like this, but specifying "disk=["phy:vg/lv,
xvda1,w,script=block-lvm"] will happily bring up the disk device using
that script. I found this digging in xen-4.4.1/tools/libxl/libxlu_disk_l.l


As an alternative, replacing block-iscsi and specifying
  disk=["iscsi:vg/lv,xvda1,w"] works as well, although deprecated (as of
libxlu_disk_l.l).


For virsh, there seems to be no way to specify the script for a disk
device in the domxml (similar to the <script/> tag for interfaces), so
virsh can't create the domU. Creating an xml using domxml-from-native
will result in

    <disk type='file' device='disk'>
      <driver name='iscsi'/>
      <source file='vg/lv'/>
      <target dev='xvda1' bus='xen'/>
    </disk>

but virsh create will result in "libxenlight does not support disk
driver iscsi" (which is wrong; same with drbd).