Description of problem:

F20 laptop running virt-manager -> RHEL7 ~beta host via ssh (with key)

I'm trying to do an install of RHEL7 onto the RHEL7 host, controlled from my laptop.
I tried to create a new VM using a URL as an installation source, it downloaded the initrd/vmlinuz but then failed with the error 

ValueError: Cannot use storage '/var/lib/libvirt/boot/virtinst-vmlinuz.OLwdRQ': '/var/lib/libvirt/boot' is not managed on the remote host.
(full backtrace below)

I can see that a boot-scratch storage pool in /var/lib/libvirt/boot has been created on the host.
This is the 1st VM creation I've tried on this host.

Version-Release number of selected component (if applicable):

F20 client:
libvirt-client-1.1.3.2-1.fc20.x86_64
libvirt-daemon-driver-qemu-1.1.3.2-1.fc20.x86_64
libvirt-daemon-driver-secret-1.1.3.2-1.fc20.x86_64
libvirt-daemon-config-network-1.1.3.2-1.fc20.x86_64
libvirt-daemon-1.1.3.2-1.fc20.x86_64
libvirt-daemon-driver-nwfilter-1.1.3.2-1.fc20.x86_64
libvirt-daemon-driver-storage-1.1.3.2-1.fc20.x86_64
libvirt-python-1.1.3.2-1.fc20.x86_64
libvirt-daemon-driver-network-1.1.3.2-1.fc20.x86_64
libvirt-daemon-kvm-1.1.3.2-1.fc20.x86_64
libvirt-daemon-driver-interface-1.1.3.2-1.fc20.x86_64
libvirt-daemon-driver-nodedev-1.1.3.2-1.fc20.x86_64
libvirt-glib-0.1.7-2.fc20.x86_64
virt-manager-common-0.10.0-5.git1ffcc0cc.fc20.noarch
virt-manager-0.10.0-5.git1ffcc0cc.fc20.noarch
libvirt-daemon-driver-storage-1.1.3.2-1.fc20.x86_64

RHEL7 host:
libvirt-glib-0.1.7-1.el7.x86_64
libvirt-daemon-driver-nwfilter-1.1.1-16.el7.x86_64
libvirt-client-1.1.1-16.el7.x86_64
libvirt-daemon-driver-nodedev-1.1.1-16.el7.x86_64
libvirt-daemon-driver-storage-1.1.1-16.el7.x86_64
libvirt-daemon-driver-interface-1.1.1-16.el7.x86_64
libvirt-daemon-driver-network-1.1.1-16.el7.x86_64
libvirt-daemon-kvm-1.1.1-16.el7.x86_64
libvirt-python-1.1.1-16.el7.x86_64
libvirt-daemon-1.1.1-16.el7.x86_64
libvirt-daemon-driver-secret-1.1.1-16.el7.x86_64
libvirt-daemon-driver-qemu-1.1.1-16.el7.x86_64
qemu-kvm-common-1.5.3-30.el7.x86_64
qemu-kvm-1.5.3-30.el7.x86_64
qemu-img-1.5.3-30.el7.x86_64


How reproducible:
It succeeded trying a second time - so I suspect this is a race involving the creation of the boot-scratch storage storage, where it's not quite ready when it comes to use it.

Steps to Reproduce:
1. Take one F20 machine with a GUI, and a remote RHEL7 machine
2. Start virt-manager, add RHEL7 machine as a connection (I'm using an ssh key)
3. Add a new machine, giving an installation URL for the OS (in this case a RHEL7 install)

Actual results:

'/var/lib/libvirt/boot' is not managed on the remote host.' during remote install

Expected results:
A nice fresh running RHEL7 guest

Additional info:
Unable to complete install: 'Cannot use storage '/var/lib/libvirt/boot/virtinst-vmlinuz.OLwdRQ': '/var/lib/libvirt/boot' is not managed on the remote host.'

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 91, in cb_wrapper
    callback(asyncjob, *args, **kwargs)
  File "/usr/share/virt-manager/virtManager/create.py", line 1959, in do_install
    guest.start_install(meter=meter)
  File "/usr/share/virt-manager/virtinst/guest.py", line 370, in start_install
    self._prepare_install(meter, dry)
  File "/usr/share/virt-manager/virtinst/guest.py", line 263, in _prepare_install
    util.make_scratchdir(self.conn, self.type))
  File "/usr/share/virt-manager/virtinst/installer.py", line 212, in prepare
    self._prepare(guest, meter, scratchdir)
  File "/usr/share/virt-manager/virtinst/distroinstaller.py", line 422, in _prepare
    self._prepare_kernel_url(guest, fetcher)
  File "/usr/share/virt-manager/virtinst/distroinstaller.py", line 346, in _prepare_kernel_url
    fetcher.meter, kernel, initrd)
  File "/usr/share/virt-manager/virtinst/distroinstaller.py", line 289, in _upload_media
    kvol = _upload_file(conn, meter, pool, kernel)
  File "/usr/share/virt-manager/virtinst/distroinstaller.py", line 119, in _upload_file
    disk.path = os.path.join(poolpath, name)
  File "/usr/share/virt-manager/virtinst/devicedisk.py", line 457, in _set_path
    self._change_backend(val, None)
  File "/usr/share/virt-manager/virtinst/devicedisk.py", line 644, in _change_backend
    path, vol_object, None, None, None)
  File "/usr/share/virt-manager/virtinst/devicedisk.py", line 118, in _distill_storage
    conn, path)
  File "/usr/share/virt-manager/virtinst/diskbackend.py", line 129, in check_if_path_managed
    raise ValueError(err)
ValueError: Cannot use storage '/var/lib/libvirt/boot/virtinst-vmlinuz.OLwdRQ': '/var/lib/libvirt/boot' is not managed on the remote host.