Description of problem:
1) created a LVM over 4 8GB virtio disks with RAID10 to be mounted on / (all in Anaconda)
2) finsihed installation successfully
3) started installation again, selected all 4 disks
4) selected reclaim and delete all
5) got this error

Version-Release number of selected component:
anaconda-20.25.10-1

The following was filed automatically by anaconda:
anaconda 20.25.10-1 exception report
Traceback (most recent call first):
  File "/tmp/updates/blivet/devicelibs/lvm.py", line 321, in vgdeactivate
    raise LVMError("vgdeactivate failed for %s: %s" % (vg_name, msg))
  File "/tmp/updates/blivet/devices.py", line 2262, in _teardown
    lvm.vgdeactivate(self.name)
  File "/tmp/updates/blivet/devices.py", line 759, in teardown
    self._teardown(recursive=recursive)
  File "/tmp/updates/blivet/deviceaction.py", line 317, in __init__
    device.teardown()
  File "/tmp/updates/blivet/__init__.py", line 1220, in destroyDevice
    action = ActionDestroyDevice(device)
  File "/tmp/updates/blivet/__init__.py", line 759, in recursiveRemove
    self.destroyDevice(leaf)
  File "/tmp/updates/pyanaconda/ui/gui/spokes/lib/resize.py", line 396, in _scheduleActions
    self.storage.recursiveRemove(device)
LVMError: vgdeactivate failed for fedora_office17: running lvm vgchange -a n fedora_office17 failed

Additional info:
cmdline:        /usr/bin/python  /sbin/anaconda
cmdline_file:   initrd=/test/mk/fedora/initrd.img root=live:http://cobra02/trees/mk/my_comps_squashfs.img nokill updates=http://cobra02/ks/mk/master_updates.img resolution=1024x768 BOOT_IMAGE=/test/mk/fedora/vmlinuz 
executable:     /sbin/anaconda
hashmarkername: anaconda
kernel:         3.11.9-300.fc20.x86_64
product:        Fedora
release:        Cannot get release name.
type:           anaconda
version:        20