Comment 10 for bug 1643902

OK, I've searched github for 'check_ceph_partitions_after_reboot' and found this:

 https://github.com/openstack/fuel-qa/blob/36f7965045329eab47e089fe67207dc39e92056e/fuelweb_test/tests/test_ceph.py#L903-L916

There are several problems in this code.

1) Device nodes' names change across reboots, just because the drive's device node used to be /dev/vdb
   before a reboot doesn't mean it's going to be the same after the reboot

2) utils.get_ceph_partitions [1] should check if the target node is up (booting the OS till networking is ready takes some time), instead of blindly reporting "No such partition" error

[1] https://github.com/openstack/fuel-qa/blob/d9d8c524ef43409c0d8a2199a1fa8dfddaa500d5/fuelweb_test/helpers/utils.py#L978-L984