Description of problem:
When creating a new storage pool for type "fs" to allow a VM to access a disk partition with an existing installation in it, an error occurs stating that the "mount point .... does not exist".  The documentation says libvirt will create it if it doesn't exist, but even if it is created separately, it still generates the same error.


Version-Release number of selected component (if applicable):
libvir 0.8.3

How reproducible:

Create a new storage pool in virt manager.

Steps to Reproduce:

1. In virt-manager, select "edit | host details | storage (tab)".  
2. Add storage pool by clicking the "+" icon.
3. New dialog opens.
   Name: test_fs
   Type: fs: Pre-formatted block device
4. click forward
   Target path: var/lib/libvirt/images/test_fs
   Format: Auto
   Host Name: (greyed out)
   Source path: /dev/sda6
   Build pool: (greyed out)
5. click finish

Actual results:

Error is displayed
Error creating pool: Could not start storage pool: cannot open volume '/var/lib/libvirt/images/test_fs/initrd.img': No such file or directory

Expected results:
Storage pool to be defined and usable.

Additional info:

Below the error this traceback info is shown:
Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/createpool.py", line 432, in _async_pool_create
    poolobj = self._pool.install(create=True, meter=meter, build=build)
  File "/usr/lib/pymodules/python2.6/virtinst/Storage.py", line 477, in install
    raise RuntimeError(errmsg)
RuntimeError: Could not start storage pool: cannot open volume '/var/lib/libvirt/images/test_fs/initrd.img': No such file or directory

syslog shows the following messages:

May 21 05:38:08 zambas libvirtd: 05:38:08.473: error : storagePoolLookupByName:299 : Storage pool not found: no pool with matching name 'test1'
May 21 05:38:46 zambas libvirtd: 05:38:46.166: error : qemudDomainGetVcpus:6044 : Requested operation is not valid: cannot list vcpu pinning for an inactive domain
May 21 05:38:46 zambas libvirtd: 05:38:46.174: error : qemudDomainGetVcpus:6044 : Requested operation is not valid: cannot list vcpu pinning for an inactive domain
May 21 05:39:06 zambas libvirtd: 05:39:06.268: error : storagePoolLookupByName:299 : Storage pool not found: no pool with matching name 'test1'
May 21 05:39:42 zambas libvirtd: 05:39:42.133: warning : qemudDispatchSignalEvent:396 : Shutting down on signal 15
May 21 05:39:48 zambas libvirtd: 05:39:48.590: warning : networkAddIptablesRules:850 : Could not add rule to fixup DHCP response checksums on network 'routed'.
May 21 05:39:48 zambas libvirtd: 05:39:48.590: warning : networkAddIptablesRules:851 : May need to update iptables package & kernel to support CHECKSUM rule.
May 21 05:39:49 zambas libvirtd: 05:39:49.189: warning : qemudStartup:1832 : Unable to create cgroup for driver: No such device or address
May 21 05:39:49 zambas libvirtd: 05:39:49.341: warning : lxcStartup:1895 : Unable to create cgroup for driver: No such device or address
May 21 05:40:07 zambas libvirtd: 05:40:07.082: warning : qemudParsePCIDeviceStrs:1422 : Unexpected exit status '1', qemu probably failed
May 21 05:40:07 zambas libvirtd: 05:40:07.085: error : qemudDomainGetVcpus:6044 : Requested operation is not valid: cannot list vcpu pinning for an inactive domain
May 21 05:40:07 zambas libvirtd: 05:40:07.088: error : qemudDomainGetVcpus:6044 : Requested operation is not valid: cannot list vcpu pinning for an inactive domain
May 21 05:40:19 zambas libvirtd: 05:40:19.939: error : storagePoolLookupByName:299 : Storage pool not found: no pool with matching name 'test2'
May 21 05:41:04 zambas libvirtd: 05:41:04.292: error : storagePoolLookupByName:299 : Storage pool not found: no pool with matching name 'test1'
May 21 05:41:16 zambas libvirtd: 05:41:16.034: error : virStorageBackendVolOpenCheckMode:984 : cannot open volume '/var/lib/libvirt/images/test1/initrd.img': No such file or directory